JP5344235B2 - Non-aqueous secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonaqueous secondary battery in which an electrode body, in which a positive and a negative electrode sheets with a mixture layer formed leaving a mixture layer non-formed portion installed at one of edges along the longitudinal direction are superposed and wound, is housed in a case, and of which reliability is improved. <P>SOLUTION: A positive electrode terminal is welded at a positive electrode side end part 301 of a wound electrode body 30 with the mixture layer non-formed portion 320A of the positive electrode sheet 320 collected to the winding center side. A negative electrode terminal is welded at a negative electrode side end part 302 of the electrode body 30 with the mixture layer non-formed portion 340A of the negative electrode sheet 340 collected to the winding center side. The tensile strength of the positive electrode current collector 322 is smaller than that of the negative electrode current collector 342, and the distance A from the end 324A of the positive electrode mixture layer to a positive electrode terminal welding part 42 is larger than the distance B from the end 344A of the negative electrode mixture layer to the negative electrode terminal welding part 82. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a non-aqueous secondary battery including a wound electrode body.

  Lithium ion secondary batteries and other non-aqueous secondary batteries are becoming increasingly important as on-vehicle power supplies or personal computers and portable terminals. In particular, a lithium ion secondary battery that is lightweight and obtains a high energy density is expected to be preferably used as a high-output power source mounted on a vehicle.

  As a typical configuration of the lithium ion secondary battery, a configuration including positive and negative electrodes including an electrode active material capable of occluding and releasing lithium ions, a separator disposed between them, and a non-aqueous electrolyte is used. Can be mentioned. For example, a positive and negative electrode sheet in which a layer mainly composed of an electrode active material (electrode mixture layer) is held by a long strip-shaped current collector is stacked with a separator between both electrode sheets, A lithium ion secondary battery having a configuration in which an electrode body (rolled electrode body) wound in the longitudinal direction is housed in a case (battery container) together with a non-aqueous electrolyte is known. Patent document 1 is mentioned as technical literature regarding this kind of battery.

JP 2005-190913 A

In the wound electrode body as described above, an electrode sheet in which the electrode mixture layer is provided while leaving one edge along the longitudinal direction of the current collector in a strip shape is used. There is a form in which both electrode sheets are overlapped so that the forming portion) protrudes from the counter electrode sheet.
An object of the present invention is to provide a non-aqueous secondary battery (typically a lithium-ion secondary battery) that is a non-aqueous secondary battery having such an electrode body and is more reliable. To do.

  In the wound type electrode body, the distance from the outermost composite layer non-formation part to the innermost circumference becomes longer as the number of windings increases, so it is necessary to weld the electrode terminal to the gathered part The width of the non-mixed material layer non-forming portion is gradually increased. Further, from the viewpoint of the welding quality and welding strength of the electrode terminals, it is advantageous that the width of the above-mentioned composite material layer non-forming portion is set with a certain margin. If there is no margin in the width of the composite material layer non-formation part or the margin is small, the composite material layer non-formation part will be gathered near the winding center at a steep angle. The current collector tends to break due to a strong stress applied to the electric body), or the welding yield tends to be lowered due to the failure to collect the composite layer non-formed part. In addition, in the electrode body in which the electrode terminal is welded to the mixture layer non-formed part gathered together at a steep angle in this way, due to impact, vibration, etc. that can be applied during battery production, distribution, use, etc. There is a concern that the current collector and the electrode terminal weld may be damaged. However, since the non-mixed material layer non-forming portion does not contribute to the battery capacity, it is desirable to make the width of the non-mixed material layer non-formed portion as small as possible from the viewpoint of increasing the energy density, reducing the weight, and reducing the material cost of the battery. There is a request.

In view of such circumstances, one non-aqueous secondary battery disclosed herein is a form in which a wound electrode body wound in a longitudinal direction is housed in a case together with a non-aqueous electrolyte, and the wound The electrode body includes a positive electrode sheet in which a positive electrode mixture layer is held on a long band positive electrode current collector, and a negative electrode sheet in which a negative electrode mixture layer is held on a long band negative electrode current collector. It has the structure wound through the separator sheet. The positive electrode sheet is provided with a strip-shaped positive electrode mixture layer non-forming portion that does not have the positive electrode mixture layer at the first edge along the longitudinal direction of the positive electrode current collector. The negative electrode sheet is provided with a strip-shaped negative electrode mixture layer non-forming portion that does not have the negative electrode mixture layer at the first edge along the longitudinal direction of the negative electrode current collector. In the positive electrode sheet and the negative electrode sheet, the positive electrode mixture layer non-forming portion protrudes from the second edge of the negative electrode sheet, and the negative electrode mixture layer non-forming portion protrudes from the second edge of the positive electrode sheet. Are overlaid. In the separator sheet, the positive electrode mixture layer non-forming portion protrudes from the first edge along the longitudinal direction of the separator sheet, and the negative electrode mixture layer is not formed from the second edge facing the first edge. The positive electrode sheet and the negative electrode sheet are overlapped so that the portion protrudes. In one end portion (positive electrode side end portion) in the axial direction of the wound electrode body, the positive electrode mixture layer non-forming portion of the positive electrode sheet is gathered to the winding center side, and the gathered positive electrode mixture The positive electrode terminal is welded to the layer non-forming part. At the other end portion (negative electrode side end portion) in the axial direction of the wound electrode body, the negative electrode mixture layer non-forming portion of the negative electrode sheet is gathered to the winding center side, and the gathered negative electrode mixture A negative electrode terminal is welded to the layer non-forming portion. Here, the tensile strength of the positive electrode current collector is lower than the tensile strength of the negative electrode current collector. The positive electrode sheet and the negative electrode sheet are
A distance A from the positive electrode mixture layer non-forming part side end of the positive electrode mixture layer to the positive electrode terminal weld,
The distance B from the negative electrode composite material layer non-formation part side end of the negative electrode composite material layer to the negative electrode terminal weld,
Is configured such that A> B.

  In this specification, “secondary battery” includes a so-called storage battery such as a lithium ion secondary battery, a metal lithium secondary battery, a nickel metal hydride battery, and a nickel cadmium battery, and a storage element such as an electric double layer capacitor. It is.

  In the battery having the above-described configuration, the distance from the end of the composite layer in each electrode sheet to the electrode terminal welded portion (hereinafter, sometimes referred to as “collecting distance”) is higher in tensile strength than the positive electrode current collector. Compared with a negative electrode sheet using a negative electrode current collector (for example, a copper foil having a thickness of about 10 μm to 20 μm), a positive electrode current collector having a lower tensile strength (for example, 0.7 to 2 times the thickness of the copper foil) In the positive electrode sheet using the aluminum foil in the range of about twice, the larger is ensured. As a result, it is possible to effectively reduce welding defects (improve yield) and improve welding strength while suppressing an increase in material cost, mass, size, and the like of the entire battery. Therefore, the battery having the above configuration is excellent in productivity and reliability.

  In addition, in a battery in which the tensile strength of the positive electrode current collector is higher than the tensile strength of the negative electrode current collector, contrary to the above configuration, the gathering distance of the negative electrode sheet is larger (longer) than the gathering distance of the positive electrode sheet. By ensuring, the same effect can be exhibited. Accordingly, the matters disclosed by this specification include the following.

A non-aqueous secondary battery in which a wound electrode body wound in a longitudinal direction is housed in a case together with a non-aqueous electrolyte. The wound electrode body includes a positive electrode sheet in which a positive electrode mixture layer is held in a long band-like positive electrode current collector, and a negative electrode sheet in which a negative electrode mixture layer is held in a long band-like negative electrode current collector, It has a configuration wound around a long strip-shaped separator sheet. The positive electrode sheet is provided with a strip-shaped positive electrode mixture layer non-forming portion that does not have the positive electrode mixture layer at the first edge along the longitudinal direction of the positive electrode current collector. The negative electrode sheet is provided with a strip-shaped negative electrode mixture layer non-forming portion that does not have the negative electrode mixture layer at the first edge along the longitudinal direction of the negative electrode current collector. In the positive electrode sheet and the negative electrode sheet, the positive electrode mixture layer non-forming portion protrudes from the second edge of the negative electrode sheet, and the negative electrode mixture layer non-forming portion protrudes from the second edge of the positive electrode sheet. Are overlaid. In the separator sheet, the positive electrode mixture layer non-forming portion protrudes from the first edge along the longitudinal direction of the separator sheet, and the negative electrode mixture layer is not formed from the second edge facing the first edge. The positive electrode sheet and the negative electrode sheet are overlapped so that the portion protrudes. At the first end in the axial direction of the wound electrode body, the positive electrode mixture layer non-forming portion of the positive electrode sheet is gathered to the winding center side, and the collected positive electrode mixture layer non-forming portion is a positive electrode terminal. Are welded. At the second end in the axial direction of the wound electrode body, the negative electrode mixture layer non-formed portion of the negative electrode sheet is gathered to the winding center side, and the gathered negative electrode mixture layer non-formed portion is connected to the negative electrode terminal. Are welded. Here, the positive and negative electrode sheets are:
Among positive and negative electrode current collectors and negative electrode current collectors, the gathering distance A ′ in the electrode sheet comprising an electrode current collector with lower tensile strength,
The gathering distance B ′ in the electrode sheet comprising an electrode current collector with higher tensile strength, and
The relationship is such that A ′> B ′.

Another non-aqueous secondary battery disclosed herein is a form in which a wound electrode body wound in a longitudinal direction is housed in a case together with a non-aqueous electrolyte, and the wound electrode body includes: A positive electrode sheet in which a positive electrode mixture layer is held on a long band-shaped positive electrode current collector, and a negative electrode sheet in which a negative electrode mixture layer is held on a long band-shaped negative electrode current collector are formed into a long band-shaped separator sheet. It has the structure wound through. The positive electrode sheet is provided with a strip-shaped positive electrode mixture layer non-forming portion that does not have the positive electrode mixture layer at the first edge along the longitudinal direction of the positive electrode current collector. The negative electrode sheet is provided with a strip-shaped negative electrode mixture layer non-forming portion that does not have the negative electrode mixture layer at the first edge along the longitudinal direction of the negative electrode current collector. In the positive electrode sheet and the negative electrode sheet, the positive electrode mixture layer non-forming portion protrudes from the second edge of the negative electrode sheet, and the negative electrode mixture layer non-forming portion protrudes from the second edge of the positive electrode sheet. Are overlaid. In the separator sheet, the positive electrode mixture layer non-forming portion protrudes from the first edge along the longitudinal direction of the separator sheet, and the negative electrode mixture layer is not formed from the second edge facing the first edge. The positive electrode sheet and the negative electrode sheet are overlapped so that the portion protrudes. At the first end portion (positive electrode side end portion) in the axial direction of the wound electrode body, the positive electrode mixture layer non-formation portion of the positive electrode sheet is gathered to the winding center side, and the gathered positive electrode composite is collected. The positive electrode terminal is welded to the material layer non-formed part. At the second end portion (negative electrode side end portion) in the axial direction of the wound electrode body, the negative electrode mixture layer non-formation portion of the negative electrode sheet is gathered to the winding center side, and the gathered negative electrode composite is gathered. The negative electrode terminal is welded to the material layer non-formed part. Here, the negative electrode current collector is made of a material having a higher thermal conductivity than the positive electrode current collector. For example, the negative electrode current collector is made of copper, and the positive electrode current collector is made of aluminum. In a preferred embodiment of such a non-aqueous secondary battery, the electrode body is in the case,
A distance E from a positive electrode mixture layer non-formation portion side end of the positive electrode mixture layer to a case inner surface (positive electrode end facing surface) facing an end surface (positive electrode side end surface) on the one end portion side of the electrode body;
From the end of the positive electrode mixture layer opposite to the positive electrode mixture layer non-forming portion side end to the case inner surface (negative electrode end facing surface) facing the other end surface (negative electrode side end surface) of the electrode body Distance F;
Are arranged such that E <F.

  In a non-aqueous secondary battery, gas may be generated inside the case due to improper use such as overcharging or unforeseen circumstances. Such gas can also be generated inside the electrode body. In the case of a wound electrode body, the discharge position of the gas generated inside the electrode body is substantially limited to the wound end face (the first end and the second end). In a situation where a large amount of gas is generated inside the wound electrode body, a large amount of heat is generated from the wound core portion of the electrode body (that is, the portion where the positive electrode mixture layer and the negative electrode mixture layer face each other). The heat is transferred to the positive electrode and negative electrode mixture layer non-forming portion, and the temperature is increased. For this reason, the gas generated in the electrode body is discharged from the electrode body through the high-temperature positive electrode end and the negative electrode end, and is concentrated on the opposing case wall surface. When such a high-temperature gas hits the case wall surface, the case wall surface may be damaged (for example, deformation or perforation of the case due to softening, melting, corrosion, etc. of the case constituent material).

  The inventor paid attention to the fact that the negative electrode side end of the electrode body is likely to be hotter than the positive electrode side end in a situation where a large amount of gas is generated inside the electrode body as described above. This is because the portion where the composite material layer non-forming portion made of the current collector with higher thermal conductivity is wound (here, the negative electrode side end portion) is the composite material layer made of the current collector with lower thermal conductivity. This is probably because the amount of heat transferred from the wound core portion is larger than the portion where the non-formed portion is wound (here, the positive electrode side end portion). Therefore, in the non-aqueous secondary battery described above, the positive electrode mixture layer that can be at a high temperature in the event of an overcharge or the like is based on the center position of the case (the central surface between the positive electrode end facing surface and the negative electrode end facing surface). It is arranged so as to be biased toward the positive electrode end facing surface side from the center position. This makes it possible to effectively reduce the maximum temperature reached on the case surface within a limited space within the case (particularly, the distance between the positive electrode end facing surface and the negative electrode end facing surface). Therefore, the non-aqueous secondary battery having the above-described configuration has a higher reliability even in the case of an abnormality caused by overcharging or the like (especially when a large amount of gas is generated in the electrode). Can be an indication. In addition, the above-described effect that the maximum temperature on the case surface can be reduced is achieved by the fact that in the assembled battery configured by arranging a plurality of the non-aqueous secondary batteries, heat transfer to adjacent single cells is achieved. It is also meaningful from the viewpoint of restraining. As described above, further excellent reliability can be realized by the combination with the configuration in which the gathering distance is A> B.

  The ratio (F / E) between the distance F and the distance E is preferably 1.1 or more, and more preferably 1.2 or more. This can better reduce the maximum temperature reached on the case surface. The upper limit of F / E is not particularly limited, but it is usually appropriate to set it to 5 or less (for example, 3 or less). If F / E is too large, the size of the battery may be easily increased.

  In a preferred aspect of the non-aqueous secondary battery disclosed herein, in the above configuration, the distance G from the first end (positive end) of the electrode body to the positive end facing surface, The electrode body is disposed so that the distance H from the second end (negative electrode side end) to the negative electrode end facing surface has a relationship of G <H. According to this aspect, the above-described effect of effectively reducing the maximum temperature reached on the surface of the case can be exhibited better.

  Note that in a battery in which the thermal conductivity of the positive electrode current collector is higher than that of the negative electrode current collector, the dimensional relationship of each part is reversed between the positive electrode side and the negative electrode side. This is the same as the gathering distance of the electrode sheets.

Another non-aqueous secondary battery disclosed herein is a form in which a wound electrode body wound in a longitudinal direction is housed in a case together with a non-aqueous electrolyte, and the wound electrode body includes: A positive electrode sheet in which a positive electrode mixture layer is held on a long band-shaped positive electrode current collector, and a negative electrode sheet in which a negative electrode mixture layer is held on a long band-shaped negative electrode current collector are formed into a long band-shaped separator sheet. It has the structure wound through. The positive electrode sheet is provided with a strip-shaped positive electrode mixture layer non-forming portion that does not have the positive electrode mixture layer at the first edge along the longitudinal direction of the positive electrode current collector. The negative electrode sheet is provided with a strip-shaped negative electrode mixture layer non-forming portion that does not have the negative electrode mixture layer at the first edge along the longitudinal direction of the negative electrode current collector. In the positive electrode sheet and the negative electrode sheet, the positive electrode mixture layer non-forming portion protrudes from the second edge of the negative electrode sheet, and the negative electrode mixture layer non-forming portion protrudes from the second edge of the positive electrode sheet. Are overlaid. In the separator sheet, the positive electrode mixture layer non-forming portion protrudes from the first edge along the longitudinal direction of the separator sheet, and the negative electrode mixture layer is not formed from the second edge facing the first edge. The positive electrode sheet and the negative electrode sheet are overlapped so that the portion protrudes. At the first end portion (positive electrode side end portion) in the axial direction of the wound electrode body, the positive electrode mixture layer non-formation portion of the positive electrode sheet is gathered to the winding center side, and the gathered positive electrode composite is collected. The positive electrode terminal is welded to the material layer non-formed part. At the second end portion (negative electrode side end portion) in the axial direction of the wound electrode body, the negative electrode mixture layer non-formation portion of the negative electrode sheet is gathered to the winding center side, and the gathered negative electrode composite is gathered. The negative electrode terminal is welded to the material layer non-formed part. Here, the negative electrode current collector is made of a material having a higher thermal conductivity than the positive electrode current collector. And the electrode body is
A distance P from the second edge of the negative electrode sheet to the first edge of the separator sheet;
A distance Q from the second edge of the positive electrode sheet to the second edge of the separator sheet;
Is configured such that P <Q. In a more preferred aspect, the relationship between the distance P and the distance R from the negative electrode composite material layer non-forming portion side end of the negative electrode composite material layer to the second edge of the separator sheet is P <R. It is configured.

  One factor that may cause a situation where a large amount of gas is generated inside the wound electrode body in the event of an overcharge or other abnormal condition is that the separator sheet heats up when the electrode body temperature rises far beyond the normal operating temperature range. It contracts, and it is mentioned that a positive electrode sheet and a negative electrode sheet contact directly (namely, short circuit) by this. The inventor paid attention to the fact that when the temperature of the electrode body rises as described above, the negative electrode side end tends to be hotter than the positive electrode side end. Therefore, in the above non-aqueous secondary battery, the end of the positive electrode mixture layer extends from the end of the positive electrode mixture layer to the end of the negative electrode side rather than the width (distance P) from which the separator sheet protrudes from the end of the negative electrode mixture layer toward the positive electrode side end. The width (distance Q) at which the separator sheet protrudes is made larger. That is, the heat shrinkage allowance of the separator sheet is more widely secured on the negative electrode end portion side where the temperature tends to be higher. By this, the performance which prevents the short circuit resulting from the thermal contraction of a separator sheet can be improved effectively. Therefore, the non-aqueous secondary battery having the above-described configuration can exhibit better reliability even in an abnormality caused by overcharge or the like. Separator sheet formed using a material containing a thermoplastic resin (typically polyethylene) such as polyolefin (typically a single layer containing at least one resin layer in which the thermoplastic resin is a continuous phase) In a battery having an aspect including a multilayer separator sheet, it is particularly meaningful to adopt the above configuration. Further, by combining with one or both of the configuration in which the gathering distance is A> B as described above and the configuration in which the electrode body is arranged so that E <F, further excellent reliability can be realized. .

  Note that in a battery in which the thermal conductivity of the positive electrode current collector is higher than that of the negative electrode current collector, the dimensional relationship of each part is reversed between the positive electrode side and the negative electrode side. This is the same as the gathering distance of the electrode sheets.

  In a preferred embodiment of any of the non-aqueous secondary batteries disclosed herein, at least one of the gap between the positive electrode mixture layer and the separator sheet and the gap between the negative electrode mixture layer and the separator sheet. A porous insulating layer containing insulating inorganic particles and a binder for binding the particles is interposed. Further, an intermediate layer containing conductive particles and a thermoplastic polymer in at least one of the space between the positive electrode current collector and the positive electrode composite material layer and between the negative electrode current collector and the negative electrode composite material layer. Is intervened. The intermediate layer forms a conductive path between the current collector and the composite layer in a normal operating temperature range of the battery, and the conductive path is cut off due to a temperature rise when the battery is abnormal. It is configured.

  According to the battery having such a configuration, even if at least a part of the separator sheet between the positive electrode mixture layer and the negative electrode mixture layer disappears due to heat shrinkage or melting, both the composite materials are utilized using the porous insulating layer. A situation where the layers are short-circuited can be avoided. Further, the function of the intermediate layer can greatly increase the resistance between the current collector and the electrode mixture layer when the battery is abnormal. By taking one or both of these measures (preferably both), it is possible to more reliably suppress an increase in battery temperature even during an abnormality such as overcharging. That is, a non-aqueous secondary battery with higher reliability can be realized. According to the combination of the above-described distances A and B, distances E and F, distances P and R, and distances P and Q, and a configuration that satisfies one or more of the relations, further excellent reliability can be realized. .

  Any non-aqueous secondary battery (for example, a lithium ion secondary battery) disclosed herein is a battery mounted on a vehicle (any non-aqueous secondary battery disclosed herein is a single battery). It can be in the form of an assembled battery comprising a plurality of batteries. Therefore, according to this invention, the vehicle (for example, motor vehicle) provided with one of the non-aqueous secondary batteries disclosed here is provided.

It is typical sectional drawing which shows the structure of the non-aqueous secondary battery which concerns on one Embodiment. It is a schematic diagram which shows the arrangement | positioning of the positive / negative electrode sheet | seat and separator sheet which comprise the non-aqueous secondary battery which concerns on one Embodiment, and the welding position of an electrode terminal. It is sectional drawing which shows typically the shape of the electrode body in the III-III line cross section of FIG. It is a schematic diagram which shows arrangement | positioning of the positive / negative electrode sheet | seat and separator sheet which comprise the non-aqueous secondary battery which concerns on other one Embodiment. It is a schematic diagram which shows the positional relationship of the positive / negative electrode sheet | seat and separator sheet which comprise the non-aqueous secondary battery which concerns on other one Embodiment, and a case. It is a schematic diagram which shows arrangement | positioning of the positive / negative electrode sheet | seat and separator sheet which comprise the non-aqueous secondary battery which concerns on other one Embodiment. It is the VII-VII sectional view taken on the line of FIG. 1 is a schematic side view showing a vehicle (automobile) provided with a nonaqueous secondary battery according to an embodiment.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

  Although not intended to be particularly limited, the present invention will be described in more detail below by taking as an example the case where the present invention is mainly applied to a lithium ion secondary battery. In addition, in the following drawings, the same code | symbol is attached | subjected to the member and site | part which show | plays the same effect | action, and the overlapping description may be abbreviate | omitted. Moreover, the dimensional relationship (length, width, thickness, etc.) in each drawing does not necessarily reflect the actual dimensional relationship.

<Embodiment 1>
As shown in FIGS. 1 to 3, a lithium ion secondary battery 10 according to the present embodiment includes a battery case 20 having a flat rectangular parallelepiped shape (that is, a square shape) and a predetermined battery constituent material (a current collector for each positive and negative electrode). And a wound electrode body 30 including a sheet-like electrode, a separator, and the like each holding an active material for each of the positive and negative electrodes is housed together with an appropriate electrolytic solution (not shown).

  The case 20 is attached to (for example, welded) a box-shaped (that is, a bottomed rectangular tube) case body 21 in which one of the narrow surfaces of the flat rectangular parallelepiped shape is an opening, and the opening. And a lid 22 that closes the opening. As a material constituting the case 20, the same materials as those used in a general lithium ion secondary battery can be appropriately used, and there is no particular limitation. From the viewpoint of heat dissipation and the like, a metal case 20 (for example, aluminum, steel, etc.) can be preferably used. The case 20 (the main body 21 and the lid body 22) of the present embodiment is made of aluminum.

  The lid 22 is formed in a rectangular shape that matches the opening shape of the case body 21. The wound electrode body 30 is a wound body having a flat shape (typically a substantially oval shape in a cross section perpendicular to the axis), and a posture in which the wound axis is laid down (that is, the case body) The opening portion 21 is accommodated in the main body 21 in such a direction that the opening portion is located in a direction transverse to the winding axis. A positive electrode terminal 40 and a negative electrode terminal 80 are respectively welded to both ends of the winding shaft of the electrode body 30. These electrode terminals 40 and 80 are respectively led out from the inside of the case 20 through terminal lead holes (not shown) provided at one end and the other end in the longitudinal direction of the lid body 22. In addition, a safety valve (not shown) is provided at the center portion of the lid body 22 to allow the inside and outside of the case to communicate with each other to release the internal pressure when the internal pressure of the case 20 rises.

  The wound electrode body 30 includes a positive electrode sheet 320 in which a positive electrode current collector layer 324 is held on a long band-like positive electrode current collector 322 and a negative electrode mixture layer 344 held on a long band-like negative electrode current collector 342. A negative electrode sheet 340 and two long strip-shaped separator sheets 36 are included. Each of the positive electrode mixture layer 324 and the negative electrode mixture layer 344 includes an active material capable of reversibly occluding and releasing lithium as a main component (typically a component that occupies 50% by mass or more of the mixture layer). Is a layer. By laminating these four sheets 340, 36, 340, 36, winding the sheet laminate in a cylindrical shape in the longitudinal direction, and then crushing the resulting wound body from the side direction and abducting it, A flat wound electrode body 30 is obtained.

The materials constituting the positive electrode sheet 320, the negative electrode sheet 340, and the separator sheet 36 may be the same as the electrode body provided in the conventional lithium ion secondary battery, and are not particularly limited. For example, for the positive electrode current collector 322 constituting the positive electrode sheet 320, an aluminum foil (this embodiment) or other metal foil suitable for the positive electrode can be suitably used. As the positive electrode active material used for forming the positive electrode mixture layer 324, one or more of materials conventionally used in lithium ion secondary batteries can be used without particular limitation. Preferable examples include lithium transition metal oxides such as LiNiO ₂ (this embodiment), LiCoO ₂ , LiMn ₂ O ₄ . Further, as the negative electrode current collector 342 constituting the negative electrode sheet 340, a metal foil suitable for copper foil (this embodiment) and other negative electrodes can be suitably used. As the negative electrode active material used for forming the negative electrode mixture layer 344, one or more of materials conventionally used in lithium ion secondary batteries can be used without any particular limitation. Preferable examples include carbon-based materials such as amorphous carbon such as natural graphite (this embodiment) and artificial graphite, lithium transition metal oxides, and lithium transition metal nitrides. Preferable examples of the separator sheet 36 include those having a single layer or a laminated structure made of a porous polyolefin resin.

  In the present embodiment, an aluminum foil having a thickness of 15 μm is used as the positive electrode current collector, and a copper foil having a thickness of 10 μm is used as the negative electrode current collector. Therefore, the tensile strength of the negative electrode current collector according to this embodiment is clearly higher than the tensile strength of the positive electrode current collector. In addition, the negative electrode current collector according to the present embodiment is made of a material that clearly has a higher thermal conductivity than the positive electrode current collector.

  The positive electrode sheet 320 is provided with a strip-shaped positive electrode mixture layer non-forming portion 320 </ b> A at a first edge 3201 along the longitudinal direction of the positive electrode current collector 322. The positive electrode mixture layer non-forming part 320 </ b> A is provided at substantially the same position on both sides of the positive electrode current collector 322. The positive electrode mixture layer 324 is formed on the surfaces of both sides of the positive electrode current collector 322 over the entire range excluding the positive electrode mixture layer non-forming portion 320A.

  The negative electrode sheet 340 is provided with a strip-shaped negative electrode mixture layer non-forming portion 340 </ b> A at a first edge 3401 along the longitudinal direction of the negative electrode current collector 342. The negative electrode mixture layer non-forming portion 340 </ b> A is provided at substantially the same position on both sides of the negative electrode current collector 342. The negative electrode mixture layer 344 is formed on the surfaces of both sides of the negative electrode current collector 342 over the entire range excluding the negative electrode mixture layer non-forming portion 340A.

  As shown in FIG. 2, the positive electrode sheet 320 and the negative electrode sheet 340 protrude from the first edge 3601 along the longitudinal direction of the separator sheet 36 so that the positive electrode mixture layer non-forming portion 320 </ b> A of the positive electrode sheet protrudes. The position is slightly shifted in the width direction (winding axis direction, that is, the left-right direction in FIG. 2) so that the negative electrode mixture layer non-forming part 340A of the negative electrode sheet protrudes from the second edge 3602 along the line. It is wound together. As a result, as shown in FIG. 1, the positive electrode mixture layer non-forming part 320 </ b> A of the positive electrode sheet is wound on one end (positive electrode side end) 301 in the winding axis direction of the wound electrode body 30. A portion that protrudes outward from the core portion 31 (that is, a portion where the positive electrode sheet 320, the negative electrode sheet 340, and the separator sheet 36 are closely wound) is formed. Further, the negative electrode mixture layer non-forming portion 340A of the negative electrode sheet protrudes outward from the wound core portion 31 at the other end portion (negative electrode side end portion) 302 in the winding axis direction of the wound electrode body 30. A part is formed.

  As well shown in FIG. 3, in the positive electrode side end portion 301 of the wound electrode body 30, the positive electrode mixture layer non-formed portion 320 </ b> A is wound from the both sides of the thickness of the electrode body (that is, the thickness center of the electrode body). Side). One flat surface side (FIGS. 1 and 2 in FIGS. 1 and 2) of the gathered portion is located slightly upward (terminal lead side) from the winding center of the electrode body (positive terminal welding portion 42). The positive electrode terminal 40 is welded from the front side (upper side in FIG. 3). Further, in the negative electrode side end portion 302 of the wound electrode body 30, the negative electrode mixture layer non-formed portion 340A is gathered from both sides of the thickness of the electrode body toward the winding center side. The negative electrode terminal 80 is welded from one flat surface side of the electrode body 30 to a portion (negative electrode terminal welded portion 82) that is slightly upward from the winding center of the electrode body in the collected portion. In order to effectively utilize the space in the case 20 and increase the energy density of the battery, the positive electrode terminal welded portion 42 and the negative electrode terminal welded portion 82 are each of the first edge of the mixture layer non-formed portions 320A and 340A. It is preferably set at a location near 3201, 3401 (preferably, a location closest to the first edge 3201, 3401).

  Here, as shown in FIGS. 2 and 3, the positive electrode sheet 320 and the negative electrode sheet 340 have a distance A (closest point) from the positive electrode mixture layer non-forming portion side end 324 </ b> A of the positive electrode mixture layer to the positive electrode terminal weld portion 42. ) Is configured to be larger than the distance B (same as above) from the negative electrode mixture layer non-forming portion side end 344A of the negative electrode mixture layer to the negative electrode terminal weld portion 82 (that is, A). > B). Thus, by making the gathering distance A of the positive electrode sheet longer than the gathering distance B of the negative electrode sheet, the gathering angle of the current collector is made gentler on the positive electrode side than on the negative electrode side, as shown in FIG. be able to. As a result, the gathering distance A can be sufficiently secured for the positive electrode sheet having a weaker tensile strength without making the gathering distance B longer than necessary for the negative electrode sheet having a high tensile strength. Therefore, it is possible to effectively realize a reduction in welding failure and an improvement in welding strength while suppressing an increase in material cost, mass, size and the like of the entire battery. As a result, a battery that is resistant to shock and vibration that can be applied during manufacture, distribution, and use of the battery, that is, a battery with higher reliability (for example, a current collector or electrode terminal weld is less likely to be damaged). Can be realized.

  The ratio (A / B) between the distance A and the distance B is preferably 1.1 or more, and more preferably 1.3 or more. Thereby, said effect of improving reliability, suppressing the enlargement of a battery, etc. can be exhibited better. The upper limit of A / B is not particularly limited, but it is usually suitably 5 or less (eg 3 or less). If A / B is too large, the size of the battery may be easily increased. Moreover, it is preferable that the value obtained by doubling the gathering distance B on the negative electrode side is 1.1 times or more with respect to the thickness T of the electrode body in the wound core portion. According to this aspect, the welding quality and welding strength on the negative electrode side can be improved. Therefore, on both the positive electrode side and the negative electrode side, the electrode body can be prevented from being damaged due to poor welding or vibration of the electrode terminals.

  The lithium ion secondary battery 10 having such a configuration can be suitably manufactured (constructed) generally by the following procedure, for example. That is, the positive electrode terminal 40 and the negative electrode terminal 80 are attached to the terminal lead hole of the lid body 22 to produce a lid body-electrode assembly. Next, the positive electrode terminal 40 and the negative electrode terminal 80 are welded to the positive electrode terminal weld portion 42 and the negative electrode terminal weld portion 82 of the wound electrode body 30 having the above-described configuration, respectively. Thereby, the lid body-electrode assembly and the electrode body 30 are integrated. In addition, as a welding method of the positive electrode terminal 40, for example, ultrasonic welding can be preferably used, and as a negative electrode terminal, for example, resistance welding can be preferably used. Then, the electrode body 30 is fitted into the opening from the opening of the case body 21 so that the lid 22 is attached to the opening, and the joint between the lid 22 and the case body 21 is sealed by, for example, laser welding. .

Thereafter, an electrolytic solution is injected into the case 20 from a liquid injection hole provided in the lid body 22. As the electrolytic solution, the same non-aqueous electrolytic solution conventionally used for lithium ion secondary batteries can be used without any particular limitation. In this embodiment, an electrolytic solution in which LiPF ₆ is contained in a mixed solvent of ethylene carbonate and diethyl carbonate (for example, a mixed solvent having a volume ratio of about 1: 1) at a concentration of about 1 mol / liter is used. Thereafter, a metal sealing cap is attached to the liquid injection hole (for example, by welding) to seal the case 20. In this way, the lithium ion secondary battery 10 can be manufactured (constructed).

<Embodiment 2>
FIG. 4 schematically shows an overlapping arrangement of the electrode sheets 320 and 340 and the separator sheet 36 constituting the electrode body of the wound electrode body 30 constituting the lithium ion secondary battery according to the present embodiment. As shown in the drawing, the electrode body 30 has a second edge of the positive electrode sheet 320 that is longer than a distance P from the second edge 3402 of the negative electrode sheet 340 to the first edge (positive electrode side end) 3601 of the separator sheet 36. The distance Q from 3202 to the second edge (negative electrode side end) 3602 of the separator sheet 36 is configured to be larger (that is, P <Q). Further, in the electrode body 30 according to this embodiment, the distance R from the negative electrode mixture layer non-formation portion side end 344A of the negative electrode mixture layer 344 to the second edge 3602 of the separator sheet 36 is more than the distance P. It is configured to be large (that is, P <R). Thus, according to the configuration in which the heat shrinkage allowance of the separator sheet is larger than that on the positive electrode end side, which is likely to be higher, the performance of preventing the short circuit due to the heat shrinkage of the separator sheet can be achieved. Can be effectively increased. Therefore, the lithium ion secondary battery having the above-described configuration can exhibit better reliability even in an abnormality caused by overcharge or the like.

  In addition, in the porous separator sheet, when the temperature rises due to abnormality of the battery or the like, the sheet constituent material (typically thermoplastic resin) is melted and the pores are blocked, thereby causing mass transfer through the sheet. Some are configured to exhibit a so-called shutdown function that stops and stops the battery reaction. However, in a large non-aqueous secondary battery that can be applied as a power source for mounting on a vehicle, the temperature can vary greatly depending on the location of the electrode body. Therefore, before the shutdown function is exerted over the entire electrode body, At the portion, the temperature of the electrode body further increases, which may cause the separator sheet to thermally contract and cause a short circuit between the electrode sheets. The above-described configuration in which the relationship between the distances P, Q, and R is P <Q or P <R is preferably applied to a large battery (for example, a battery for a vehicle power supply) and exhibits the above-described effects. be able to.

<Embodiment 3>
In the lithium ion secondary battery 10 according to the present embodiment, as shown in FIG. The case from the end opposite to the positive electrode mixture layer non-formation portion side end of the positive electrode mixture layer (in this embodiment, coincides with the positive electrode side end of the electrode body 30) than the distance E to the extreme facing surface 20A. 20 is arranged such that the distance F to the negative electrode end facing surface 20B is larger (that is, E <F). In this way, the positive electrode mixture layer is limited by being disposed so as to be biased toward the positive electrode end facing surface side of the case (positive electrode end side constituted by a current collector made of a material having lower thermal conductivity). By effectively using the space in the case, the maximum temperature reached on the case surface can be effectively reduced. Therefore, the lithium-ion secondary battery having the above-described configuration has a higher reliability even in the case of an abnormality caused by overcharging or the like (especially when a large amount of gas is generated in the electrode). Can be an indication.

  Hereinafter, some experimental examples related to the present invention will be described, but the present invention is not intended to be limited to those shown in the specific examples.

<Experimental example 1>
In order to confirm the effect of adopting the above configuration, the following experiment was conducted. That is, a total of six types of lithium ion secondary batteries (samples 1A to 6A) in which the distances A and B shown in FIG. .

  The following was used as the positive electrode sheet. That is, acetylene black (conductive material) having an average particle diameter of 48 nm and PVDF (polymer material) are mixed with NMP so that the mass ratio of the conductive material / polymer material is about 30/70 and the solid content is about 10% by mass. By mixing, a solvent-based intermediate layer forming composition was prepared.

Also, LiNiO ₂ powder (positive electrode active material), acetylene black and CMC are mixed with ion-exchanged water so that the mass ratio of these materials is 87: 10: 3 and the solid content is about 45 mass%, An aqueous positive electrode composition layer forming composition was prepared.

As shown in the schematic diagrams of FIGS. 6 and 7, the intermediate layer forming composition is applied to the surfaces of both sides of an aluminum foil (positive electrode current collector) 322 having a thickness of 15 μm and dried, whereby the current collector is collected. An intermediate layer 323 was formed on both sides of the body 322. The coating amount of the intermediate layer forming composition was adjusted so as to be about 2 g / m ² per one side of the current collector 322 on a solid basis (that is, a mass basis after drying). The application range of the intermediate layer forming composition was set to a range approximately 4 mm wider than the application range of the positive electrode mixture layer forming composition described later.

On the positive electrode current collector 322 having the intermediate layer 323 formed thereon, a strip-shaped portion having a predetermined width from the first edge 3201 along the longitudinal direction of the current collector (a positive electrode mixture having a width 5 mm wider than the distance A shown in Table 1) A positive electrode mixture layer 324 was formed on each intermediate layer 323 by applying the composition for forming a positive electrode mixture layer to the remaining range excluding the layer non-forming part 320A) and drying it. The coating amount (solid content basis) of the composition for forming the positive electrode mixture layer was adjusted to 50 g / m ² per one side of the positive electrode current collector 322. Then, it pressed so that the whole thickness might be set to 70 micrometers, and the positive electrode sheet 320 was obtained.

The following was used as the negative electrode sheet. That is, natural graphite (powder), SBR, and CMC are mixed with ion-exchanged water so that the mass ratio of these materials is 98: 1: 1 and the solid content is 45% by mass. A material layer forming composition was prepared. This composition is applied to the surface of both sides of a copper foil (negative electrode current collector) 342 having a thickness of about 10 μm from a first edge 3401 along the longitudinal direction of the current collector (shown in Table 1). The negative electrode mixture layer 344 was formed on both surfaces of the current collector 342 by applying and drying the remaining area excluding the negative electrode mixture layer non-forming portion 340A) 5 mm wider than the distance A). The coating amount (solid content basis) of the negative electrode composite layer forming composition was adjusted to 40 g / m ² per one side of the negative electrode current collector 342.

An α-alumina powder having an average particle size of 0.8 μm and an acrylic binder are mixed with NMP so that the mass ratio of these materials is 90:10 and the solid content is 50% by mass, to obtain a slurry solvent A system coating agent was prepared. The coating agent was applied to the negative electrode current collector 342 on which the negative electrode mixture layer 344 was formed and dried to form a porous insulating layer 346 on each negative electrode mixture layer 344. The coating amount (based on solid content) of the coating agent was adjusted to 8 g / m ² per side of the negative electrode current collector 342. The coating range of the coating agent was about 4 mm wide from the coating range of the composition for forming a negative electrode mixture layer. Then, it pressed so that the whole thickness might be set to 75 micrometers, and the negative electrode sheet 340 was obtained.

  The positive electrode sheet 320 and the negative electrode sheet 340 produced as described above were separated into two separator sheets 36 (thickness 20 μm, width 85 mm, length 5000 mm, an intermediate layer made of PE resin between the front layer and the back layer made of PP resin) The separator sheet having a three-layer structure was used, and this was also referred to as “PP / PE / PP sheet”. At this time, the distance P from the second edge 3402 of the negative electrode sheet 340 to the first edge 3601 of the separator sheet 36 is 2 mm, and from the second edge 3202 of the positive electrode sheet 320 to the second edge 3602 of the separator sheet 36. The alignment was performed such that the distance Q was 7 mm, and the distance R from the negative electrode mixture layer non-forming portion side end 344A of the negative electrode mixture layer 344 to the second edge 3602 of the separator sheet 36 was 4 mm (Experimental Example 2 described later) The same conditions as Sample 1B in FIG. The laminated sheet thus laminated was wound in the longitudinal direction (number of windings: about 30 times), and the wound body was crushed from the side to obtain a flat wound electrode body. The thickness of the wound core portion of this electrode body was 11 mm.

  In the positive electrode side end portion of the wound electrode body obtained above, the positive electrode mixture layer non-formed part is gathered in the thickness direction of the electrode body, with a width of 5 mm from the end of the gathered positive electrode current collector, Aluminum positive terminals were joined by ultrasonic welding. Further, at the negative electrode side end portion of the electrode body, the negative electrode mixture layer non-formed portion is gathered in the thickness direction of the electrode body, and a copper negative electrode terminal having a width of 5 mm from the end of the gathered negative electrode current collector Were joined by resistance welding. At this time, if the current collector (metal foil) was observed to be broken or cut at the welded part or in the vicinity thereof, it was determined that the weld was defective. Twenty electrode bodies were prepared for each of Samples 1A to 6A, terminals were welded, and the occurrence rate of defective welding (number of defects / number of products) was evaluated. The results are shown in Table 1.

  Of the 20 electrode bodies according to Samples 1A to 5A, 10 were prepared (selected) for which no terminal welding failure was observed, and lithium ion secondary batteries were produced using these electrode bodies. . As the battery case, a container having a flat box-shaped outer shape having a height of 9 cm, a width of 11 m, and a depth of 1.2 cm was used. The case includes a bottomed square cylindrical case main body and a lid that is attached to the opening and closes the opening. Both the case main body and the lid are made of aluminum, and the thickness of the aluminum constituting the case main body is 0.5 mm. The wound electrode body was accommodated in the case. At this time, the distance E from the positive electrode mixture layer non-forming portion side end of the positive electrode mixture layer to the positive electrode end facing surface of the case is 16 mm, and the distance F from the second edge of the positive electrode sheet to the negative electrode end facing surface of the case The accommodation position of the wound electrode body was adjusted so as to be 20 mm (see FIG. 5).

And after welding the joint of a case main body and a cover body, electrolyte solution was inject | poured from the liquid injection hole provided in the cover body, and the said liquid injection hole was then sealed. As an electrolytic solution, a mixture solvent containing EC, DMC, and EMC in a volume ratio of 1: 1: 1 contains lithium hexafluorophosphate (LiPF ₆ ) as a supporting salt at a concentration of about 1 mol / liter. It was used. Thereafter, an initial charge / discharge treatment (conditioning) was performed by a conventional method to obtain a lithium ion secondary battery according to this example. The theoretical capacity of this lithium ion secondary battery is 5 Ah.

  These batteries were subjected to a T3 vibration test based on the United Nations Recommendations on the Transport of Dangerous Goods. Table 1 shows the ratio of the number of batteries in which the current collector was damaged by this vibration test. Note that the vibration test was not performed on sample 6A because the welding defect rate was high in the above welding.

  As shown in Table 1, samples 1A to 4A in which the relationship between distances A and B is A <B (that is, A / B> 1) are welded compared to samples 5A and 6A in which A ≦ B. A clear reduction effect was observed in the defect rate and the failure rate by the vibration test. Further, as apparent from the comparison between the samples 3A and 5A and the samples 4A and 6A in which the total value (A + B) of the gathering distances on the positive electrode side and the negative electrode side is the same, both electrode sheets can be obtained by applying the relationship of A <B. It was confirmed that the welding failure rate and the failure rate by the vibration test can be greatly reduced without increasing the width of the electrode composite material layer non-forming portion.

<Experimental example 2>
Experimental example except that distance A and distance B were fixed to 9 mm and 8 mm, respectively (same conditions as in sample 2A of experimental example 1), and distances P, Q, and R were adjusted to the values shown in Table 2, respectively. In the same manner as in Example 1, 20 lithium ion secondary batteries (samples 1B to 8B) in total of 20 were produced. After conditioning, the batteries were adjusted to 100% SOC (state of charge) with constant current and constant voltage charge (cut current 0.1 A) of 5 A (corresponding to 1 C) and 4.1 V, and 25 ° C. After measuring the voltage between terminals of each battery in an environment, 10 pieces were carried in a temperature environment of 130 ° C. and 150 ° C., and left at that temperature for 1 hour. Then, the voltage between terminals of each battery was measured again under an environment of 25 ° C., and the ratio of batteries in which a voltage change of 0.1 V or more was observed. The results are shown in Table 2.

  As shown in Table 2, the samples 1B to 4B in which the distance P and the distance Q satisfy the relationship P <Q are compared to the samples 5B to 8B that do not satisfy the relationship (that is, P ≧ Q). The voltage stability at was clearly good. According to the samples 1B to 3B in which the distance P and the distance R satisfy the relationship of P <R, a better result was realized in the standing test at a high temperature (150 ° C.).

<Experimental example 3>
Except that the distance A and the distance B are fixed to 9 mm and 8 mm, respectively (the same conditions as the sample 2A of Experimental Example 1), and the positions of the electrode bodies are adjusted so that the distances E and F have the values shown in Table 2, respectively. Produced a total of six types of lithium ion secondary batteries (Samples 1C to 6C) in the same manner as in Experimental Example 1. The batteries were adjusted to SOC 60% under the same charging conditions as in Experimental Example 2 after conditioning, and charged at 150 A (corresponding to 30 C) for 5 seconds and discharged at 150 A for 3 seconds under a temperature condition of 60 ° C. Was repeated until the upper limit voltage reached 100V. Meanwhile, the maximum temperature reached on the case side surface of each sample was measured by tracking the temperature transition of each part of the case side surface (the outer surface of the positive electrode end facing surface and the negative electrode end facing surface) using a thermocouple. The results are shown in Table 3.

  As shown in Table 3, according to the samples 1C to 3C in which the distance E and the distance F satisfy the relationship of E <F, compared to the samples 4C to 6C that do not satisfy the relationship (that is, E ≧ F), The maximum temperature reached on the surface (here, the side surface) could be significantly reduced. In addition, comparison between samples 1C and 3C (example of E <F) and samples 4C and 5C (example of E ≧ F) having the same value of E + F, and sample 1C (example of E <F) and sample 6C (E>) As can be seen from the comparison with F 鄭), the case surface can be obtained without increasing the physique of the battery (particularly, the distance between the positive electrode end facing surface and the negative electrode end facing surface) by applying the relationship of E <F. It was confirmed that the maximum temperature reached could be greatly reduced.

  The battery according to sample 1C was adjusted to SOC 30% under the same charging conditions as in Experimental Example 2 after conditioning, and overcharged at 4C-60V (with a constant current of 4C up to 60V) and 20C-60V. A test was conducted. As a result, the maximum reached temperatures were 115 ° C. and 98 ° C., respectively. Moreover, about the battery similarly constructed except the point which did not form the porous insulating layer in the negative electrode compound-material layer surface, when the overcharge test of 4C-60V and 20C-60V was done similarly, The highest temperatures reached were 115 ° C and 105 ° C, respectively. This result shows that the maximum temperature reached can be further reduced by providing a porous insulating layer (in other words, the installation of the porous insulating layer is effective to reduce the maximum temperature). It is something to support.

  As mentioned above, although this invention was demonstrated in detail, the said embodiment is only an illustration and what changed and modified the above-mentioned specific example is included in the invention disclosed here.

  A non-aqueous secondary battery (for example, a lithium ion secondary battery) provided by the technology disclosed herein is excellent in reliability as described above, and therefore, a power source for a motor (electric motor) mounted on a vehicle such as an automobile. Can be suitably used. Therefore, as schematically shown in FIG. 8, the present invention is one of the lithium ion secondary batteries 10 disclosed herein (in the form of an assembled battery 100 formed by connecting a plurality of the batteries 10 in series. 1 is provided as a power source (typically, an automobile, in particular, an automobile including an electric motor such as a hybrid vehicle, an electric vehicle, and a fuel cell vehicle).

1 Automobile (vehicle)
10 Non-aqueous secondary battery (lithium ion secondary battery)
20 battery case 20A positive electrode end facing surface 20B negative electrode end facing surface 30 wound electrode body (electrode body)
301 One end (positive electrode side end)
302 The other end (negative electrode side end)
30A One end side end face (positive side end face)
30B End surface on the other end side (negative electrode side end surface)
31 wound core portion 320 positive electrode sheet 320A positive electrode mixture layer non-forming part 3201 first edge 3202 second edge 322 positive electrode current collector 323 intermediate layer 324 positive electrode mixture layer 340 negative electrode sheet 340A negative electrode mixture layer non-forming part 3401 First edge 3402 Second edge 342 Negative electrode current collector 344 Negative electrode mixture layer 346 Porous insulating layer 36 Separator sheet 3601 First edge (positive electrode side end)
3602 Second edge (negative electrode side end)
40 Positive terminal (electrode terminal)
42 Positive terminal welded portion 80 Negative terminal 82 Negative terminal welded portion

Claims (6)

A positive electrode sheet in which a positive electrode mixture layer is held on a long belt-like positive electrode current collector and a negative electrode sheet in which a negative electrode mixture layer is held on a long belt-like negative electrode current collector are elongated through a long belt-like separator sheet. A non-aqueous secondary battery in which a wound electrode body wound in a direction is accommodated in a case together with a non-aqueous electrolyte,
The positive electrode sheet is provided with a strip-shaped positive electrode mixture layer non-forming portion not having the positive electrode mixture layer on the first edge along the longitudinal direction of the positive electrode current collector,
The negative electrode sheet is provided with a strip-shaped negative electrode mixture layer non-forming portion not having the negative electrode mixture layer on the first edge along the longitudinal direction of the negative electrode current collector,
In the positive electrode sheet and the negative electrode sheet, the positive electrode mixture layer non-forming portion protrudes from the second edge of the negative electrode sheet, and the negative electrode mixture layer non-forming portion protrudes from the second edge of the positive electrode sheet. Are superimposed so that
In the separator sheet, the positive electrode mixture layer non-forming portion protrudes from the first edge along the longitudinal direction of the separator sheet, and the negative electrode mixture layer is not formed from the second edge facing the first edge. Is overlapped with the positive electrode sheet and the negative electrode sheet so that the part protrudes,
At one end portion in the axial direction of the wound electrode body, the positive electrode mixture layer non-forming portion of the positive electrode sheet is gathered to the winding center side, and the collected positive electrode mixture layer non-forming portion is positive. The terminals are welded,
At the other end in the axial direction of the wound electrode body, the negative electrode mixture layer non-formed portion of the negative electrode sheet is gathered together toward the winding center side, and the gathered negative electrode mixture layer non-formed portion is negative The terminals are welded,
The negative electrode current collector is made of a material having a larger thermal conductivity than the positive electrode current collector,
The electrode body is in the case,
Distance E from the positive electrode mixture layer non-formation portion side end of the positive electrode mixture layer to the case inner surface facing the end surface on the one end portion side of the electrode body;
A distance F from an end of the positive electrode mixture layer opposite to a positive electrode mixture layer non-formation portion side end to an inner surface of the case facing the other end side end surface of the electrode body;
The non-aqueous secondary battery is arranged so that the relationship of E <F. A positive electrode sheet in which a positive electrode mixture layer is held on a long belt-like positive electrode current collector and a negative electrode sheet in which a negative electrode mixture layer is held on a long belt-like negative electrode current collector are elongated through a long belt-like separator sheet. A non-aqueous secondary battery in which a wound electrode body wound in a direction is accommodated in a case together with a non-aqueous electrolyte,
The positive electrode sheet is provided with a strip-shaped positive electrode mixture layer non-forming portion not having the positive electrode mixture layer on the first edge along the longitudinal direction of the positive electrode current collector,
The negative electrode sheet is provided with a strip-shaped negative electrode mixture layer non-forming portion not having the negative electrode mixture layer on the first edge along the longitudinal direction of the negative electrode current collector,
In the positive electrode sheet and the negative electrode sheet, the positive electrode mixture layer non-forming portion protrudes from the second edge of the negative electrode sheet, and the negative electrode mixture layer non-forming portion protrudes from the second edge of the positive electrode sheet. Are superimposed so that
In the separator sheet, the positive electrode mixture layer non-forming portion protrudes from the first edge along the longitudinal direction of the separator sheet, and the negative electrode mixture layer is not formed from the second edge facing the first edge. Is overlapped with the positive electrode sheet and the negative electrode sheet so that the part protrudes,
At one end portion in the axial direction of the wound electrode body, the positive electrode mixture layer non-forming portion of the positive electrode sheet is gathered to the winding center side, and the collected positive electrode mixture layer non-forming portion is positive. The terminals are welded,
At the other end in the axial direction of the wound electrode body, the negative electrode mixture layer non-formed portion of the negative electrode sheet is gathered together toward the winding center side, and the gathered negative electrode mixture layer non-formed portion is negative The terminals are welded,
The negative electrode current collector is made of a material having a larger thermal conductivity than the positive electrode current collector,
The electrode body is
A distance P from the second edge of the negative electrode sheet to the first edge of the separator sheet;
A distance Q from the second edge of the positive electrode sheet to the second edge of the separator sheet;
A non-aqueous secondary battery configured so that the relationship of P <Q. The electrode body is
The distance P;
A distance R from the negative electrode composite material layer non-forming part side end of the negative electrode composite material layer to the second edge of the separator sheet;
The non-aqueous secondary battery according to claim 2 , wherein the relationship is P <R. At least one of between the positive electrode mixture layer and the separator sheet and between the negative electrode mixture layer and the separator sheet includes a porous material including insulating inorganic particles and a binder that binds the particles. An insulating layer is interposed, and
At least one of between the positive electrode current collector and the positive electrode composite material layer and between the negative electrode current collector and the negative electrode composite material layer has an intermediate layer containing conductive particles and a thermoplastic polymer. Intervened,
The intermediate layer forms a conductive path between the current collector and the composite layer in a normal operating temperature range of the battery, and the conductive path is cut off due to a temperature rise when the battery is abnormal. The nonaqueous secondary battery according to any one of claims 1 to 3 , wherein the nonaqueous secondary battery is configured as follows. An assembled battery comprising the nonaqueous secondary battery according to any one of claims 1 to 4 as a single battery, and a plurality of the single batteries. A vehicle comprising the nonaqueous secondary battery according to any one of claims 1 to 4 .

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