JP4211623B2 - Electrode laminated battery - Google Patents

Description

  The present invention relates to an electrode laminated battery, and more particularly to an electrode laminated battery such as a lithium ion polymer secondary battery having a laminated structure in which an electrolyte layer, a positive electrode, and a negative electrode are laminated by winding or the like.

  In recent years, portable electronic devices such as notebook personal computers, mobile phones, and PDAs (Personal Digital Assistants) have become widespread, and lithium ion batteries having advantages such as high voltage, high energy density, and light weight have been widely used as power sources.

  Furthermore, as a countermeasure against liquid leakage that becomes a problem when using a liquid electrolyte, for example, an electrolyte that uses a gel polymer film in which a polymer is impregnated with a nonaqueous electrolyte, or an all-solid electrolyte is used. A lithium ion polymer secondary battery using an electrolyte has been put into practical use.

  A polymer lithium ion battery has a positive electrode, a negative electrode, and a polymer electrolyte, and has a cell structure in which a battery element from which a lead is led out from the positive electrode and the negative electrode is covered with an exterior material such as an aluminum laminate. Furthermore, the cell is configured to be housed in a box-shaped plastic mold case composed of upper and lower cases together with a wiring board on which a circuit portion is mounted.

  The polymer lithium ion battery needs to have a structure in which the reaction area is increased to reduce the internal resistance. Therefore, when a polymer lithium ion battery is formed, a plurality of electrodes are stacked by winding or the like according to the thickness of the battery to be formed to increase the reaction area. In the present specification, a battery having such a structure in which a plurality of electrodes are laminated is referred to as an electrode laminated battery.

  The electrode laminated battery has a possibility that the positive electrode and the negative electrode are electrically short-circuited due to secular change or external pressing force.

  In Patent Document 1 below, among the positions of the end portions of at least one of the positive electrode and the negative electrode, at least the insulation covering the other electrode facing the position exposed to the outside from the electrolyte layer A lithium ion battery having a structure with a conductive covering material is described.

JP 2001-266946 A

  In the lithium ion battery having the structure described in Patent Document 1, it is possible to prevent an electrical short circuit between the positive electrode and the negative electrode due to secular change or application of a pressing force from the outside.

  However, when the electrode laminated battery is provided with an insulating coating material that prevents electrical short-circuiting, setting of the electrode winding start and winding end positions, arrangement of insulating materials such as tape provided on the negative electrode and the positive electrode, etc. Therefore, there is a possibility that the thickness of the battery is locally increased, and there is a problem that the thickness of the electrode and the insulating material is limited.

  Therefore, the cell thickness cannot be averaged between the positive electrode lead terminal side and the negative electrode lead terminal side, the thickness of one of the lead terminals is locally increased, the thickness of the electrode or insulating material is reduced, and the battery capacity is reduced. Had to be restricted.

  Therefore, an object of the present invention is to prevent a short circuit between the positive electrode and the negative electrode, and to average the thicknesses of the positive electrode lead terminal side and the negative electrode lead terminal side to provide a safe and high volume energy density electrode laminated battery. It is to provide.

In order to achieve the above object, the invention according to claim 1 has a structure in which the positive electrode and the negative electrode are alternately laminated via the electrolyte, and the lamination is made by winding the positive electrode and the negative electrode. In the electrode laminated battery, the positive electrode is composed of a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector so that at least a part of the positive electrode current collector is exposed. A negative electrode current collector composed of a current collector and a negative electrode mixture layer formed on the negative electrode current collector so that at least a part of the negative electrode current collector is exposed, and may be in contact with the exposed portion of the positive electrode current collector An insulating coating material is provided on the exposed portion of the positive electrode current collector that may be in contact with the exposed portion of the body and / or the exposed portion of the negative electrode current collector, and the positive electrode and the negative electrode are alternately laminated. as dressing thickness becomes uniform is disposed et provided at one end of the cathode current collector The positive electrode lead terminal is disposed on one end side in the longitudinal direction of the wound cross section, and the negative electrode lead terminal provided on one end of the negative electrode current collector is disposed on the other end side in the longitudinal direction. The other end side of the positive electrode current collector and the negative electrode current collector is wound so that the positive electrode is on the outside and the negative electrode is on the inner side so that the body is first folded on the positive electrode lead terminal side. This is an electrode laminated battery in which the position of the electromotive portion end overlaps with the positive electrode lead terminal on the side that is first folded, or between the first folded portion and the positive electrode lead terminal .

  In the present invention, a positive electrode composed of a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector so that at least a part of the positive electrode current collector is exposed, and the negative electrode current collector and the negative electrode current collector A negative electrode composed of a negative electrode mixture layer formed on a negative electrode current collector so that at least a part of the body is exposed can be alternately stacked via an electrolyte, and can be in contact with an exposed part of the positive electrode current collector By providing an insulating coating on the exposed portion of the negative electrode current collector and / or the exposed portion of the positive electrode current collector that may be in contact with the exposed portion of the negative electrode current collector, An electrical short circuit between the electrodes due to the pressure being applied can be prevented, and the covering material is disposed so that the thickness when the positive electrode and the negative electrode are alternately laminated is uniform. Make the thickness of the positive lead terminal side and the negative lead terminal side uniform. Rukoto can.

  Therefore, according to this invention, there exists an effect that a safe and high volume energy density electrode laminated battery can be provided.

  Hereinafter, an electrode laminated battery according to an embodiment of the present invention will be described with reference to the drawings. The electrode laminated battery in the embodiment of the present invention refers to a battery having a structure in which positive electrodes and negative electrodes are alternately laminated via an electrolyte. Hereinafter, the electrode laminated battery according to the first embodiment will be described by taking a lithium ion polymer secondary battery as an example.

  FIG. 1 shows an example of a schematic configuration of a lithium ion polymer secondary battery in which electrodes are stacked by winding. In addition, in the drawings of the schematic configuration of the battery to be referred to below and the detailed description based thereon, in order to avoid complication of illustration and description, the part of the laminated structure inside the battery will be particularly extracted and described, and other aluminum laminates will be described. About the structure of exterior materials etc. comprised with a film etc., since it is the same structure as the past, it abbreviate | omits.

  The lithium ion polymer secondary battery shown in FIG. 1 has a configuration in which a positive electrode and a negative electrode are alternately stacked by winding. The positive electrode is composed of a positive electrode current collector 1 and a positive electrode active agent layer 2 formed on the positive electrode current collector 1. The negative electrode is composed of a negative electrode current collector 7 and a negative electrode mixture layer 6 formed on the negative electrode current collector 7. The electrolyte is separated into a positive electrode side electrolyte layer 3 and a negative electrode side electrolyte layer 5 by a separator 4. Moreover, it has the lead terminal 8 on the positive electrode side and the lead terminal 9 on the negative electrode side, and the covering materials 10a, 10b, 10c, 10d, 10e, 10f, and 10g as its main structure.

  In FIG. 1, in order to simplify the illustration, the laminated structure is wound around about twice so that the lead terminal 8 and the lead terminal 9 are located closer to the center. Needless to say, it may actually be wound more times. However, the winding start part and the end part of each layer are the same as the positional relationship shown in FIG.

  Here, the laminated portion will be described in detail. FIG. 2 is an enlarged view of the stacked portion of the lithium ion polymer secondary battery shown in FIG. The positive electrode 11 and the negative electrode 12 are a battery positive electrode and a battery negative electrode, respectively, and preferably have good conductivity and chemical properties as an electrode, good workability at the time of winding, light weight and low cost.

  The positive electrode current collector 1 and the positive electrode active agent layer 2 constituting the positive electrode 11 have the same configuration as that of a conventional lithium ion polymer secondary battery. For example, the positive electrode current collector 1 is a metal foil made of aluminum or the like. The positive electrode active agent layer 2 is a film material containing an active material such as lithium, cobalt, manganese, nickel, cadmium, and graphite graphite, a binder for adhering to the positive electrode current collector 1 and the like.

  The negative electrode current collector 7 and the negative electrode mixture layer 6 constituting the negative electrode 12 have the same configuration as that of a conventional lithium ion polymer secondary battery. For example, the negative electrode current collector 7 is a metal foil made of copper or the like. The negative electrode mixture layer 6 is a film material containing an active material such as a carbon material, a binder for adhering to the negative electrode current collector 7 and the like.

  The electrolyte layer 3 and the electrolyte layer 5 constituting the electrolyte 13 have the same configuration as a conventional lithium ion polymer secondary battery. That is, the electrolyte layer 3 and the electrolyte layer 5 are made of gel-like polymer, have electrochemical characteristics suitable as the electrolyte layer, and the electrolyte does not leak in a liquid state and is not bent or bent. It is made of an acceptable gel material. A material satisfying such characteristics is preferably, for example, a material in which an electrolyte is homogeneously dispersed in a polymer matrix. The electrolyte 13 is divided into an electrolyte layer 3 and an electrolyte layer 5 by a separator 4.

  The separator 4 is used for a conventional lithium ion polymer secondary battery. That is, the separator 4 separates both the electrolyte layer 3 and the electrolyte layer 5 so as not to intermingle, and allows ions to move between the positive electrode 11 and the negative electrode 12 sufficiently freely in practice. For example, microporous polypropylene or the like is suitable.

  In the present specification, a set of layer configurations between the same electrodes sandwiching different electrodes is referred to as a pair of a positive electrode and a negative electrode. For example, in FIG. 2, the negative electrode 12 is sandwiched between the positive electrodes 11, and in this case, between the positive electrode 11 and the positive electrode 11, that is, the positive electrode current collector 1, the positive electrode active agent layer 2, the electrolyte layer 3, A pair of layer configurations each including a separator 4, an electrolyte layer 5, a negative electrode mixture layer 6, a negative electrode current collector 7, a negative electrode mixture layer 6, an electrolyte layer 5, a separator 4, an electrolyte layer 3, and a positive electrode active agent layer 2 are paired. This is a set of a positive electrode and a negative electrode.

  Therefore, in the case of the lithium ion polymer secondary battery having the configuration shown in FIG. 1, for example, at the position overlapping the lead terminal 9, the above-described pair of positive electrode and negative electrode is 1.5 (on the lead terminal 9) +1 .5 (under the lead terminal 9) = 3 layers exist.

  The lead terminal 8 and the lead terminal 9 shown in FIG. 1 are for taking out the electromotive force generated in the laminated structure to the outside. The lead terminal 8 and the lead terminal 9 have the same configuration as a conventional lithium ion polymer secondary battery, aluminum having good conductivity and durability against chemical reaction inside the laminated structure, an aluminum-containing alloy, It is composed of a thin plate made of platinum, a platinum-containing alloy, gold, a gold-containing alloy, or the like. The lead terminal 8 is joined to the end of the positive electrode current collector 1 on the winding start side by welding or the like. The lead terminal 9 is joined to the end of the negative electrode current collector 7 on the winding start side by welding or the like. The winding start side refers to the inner peripheral side that is the start of winding, and the winding end side refers to the outer peripheral side that is the end of winding.

  In this lithium ion polymer secondary battery, a positive electrode current collector 1 coated with a positive electrode active agent layer 2 and a negative electrode current collector 7 coated with a negative electrode mixture layer 6 are provided, with a positive electrode 11 on the outer side and a negative electrode 12 on the inner side. Thus, the positive electrode 11 and the negative electrode 12 are alternately laminated. More specifically, the lead terminal 8 provided at one end of the positive electrode current collector 1 is disposed at one end side in the longitudinal direction of the wound cross section, and the lead terminal 9 provided at one end of the negative electrode current collector 7 is disposed at the wound cross section. The other end side of the positive electrode current collector 1 and the negative electrode current collector so that both the positive electrode current collector 1 and the negative electrode current collector 7 are first turned back on the lead terminal 8 side. The other end side of the body 7 is wound.

  The positive electrode active agent layer 2 is not applied to the positive electrode current collector 1 on the outermost peripheral surface. Further, the negative electrode mixture layer 6 is not applied to the innermost negative electrode current collector 7. Further, the positive electrode active agent layer 2 is not applied to both surfaces of both ends of the positive electrode current collector 1. The negative electrode mixture layer 6 is not applied to both surfaces of both ends of the negative electrode current collector 7. Therefore, the positive electrode active material layer 2 is formed on the positive electrode current collector 1 so that at least a part of the positive electrode current collector 1 is exposed. The negative electrode mixture layer 6 is formed on the negative electrode current collector 7 so that at least a part of the negative electrode current collector 7 is exposed.

  All of the covering materials 10a, 10b, 10c, 10d, 10e, 10f, and 10g disposed at the respective positions of the positive electrode current collector 1 and the negative electrode current collector 7 have a pressing force with respect to the electrode of the laminated structure from the outside. Even when one electrode and the other electrode are brought into proximity with each other when applied, they are made of a material having an insulating property for electrically insulating the electrodes. Further, the covering materials 10a, 10b, 10c, 10d, 10e, 10f, and 10g may be torn or damaged even if one electrode is deformed by the application of such a pressing force and contacts the other electrode. It has a material and thickness with no mechanical strength, and is formed by bonding a tape made of polyimide or polypropylene, for example, to a corresponding portion.

  The positive electrode current collector 1 and the negative electrode current collector 7 are generally formed so as to be longer than the position where the electrolyte 13 is interposed with a margin at the ends thereof. This is because the electrolyte layer 3 and the electrolyte layer 5 can be completely in contact with the electrodes when the laminated structure is formed by applying or adhering the electrolyte layer 3 and the electrolyte layer 5 on the main surface of each current collector. It is to make it. The amount of exposure (protrusion) at the end of the current collector may be further increased due to the displacement of each electrode when a pressing force is applied after the lamination is formed. In addition, since the electrolyte layer 3 and the electrolyte layer 5 are gel-like and easily deformed, when a pressing force is applied to the laminated structure from the outside during manufacturing of the battery and during use as a product, the entire laminated structure is compressed. As a result, the portions exposed from the electrolyte layer 3 and the electrolyte layer 5 at the end of the current collector are in close proximity to each other.

  However, the lithium ion polymer secondary battery may be in contact with the exposed portion of the negative electrode current collector 7 and / or the exposed portion of the negative electrode current collector 7 which may be in contact with the exposed portion of the positive electrode current collector 1. Since the covering material is provided on the exposed portion of a certain positive electrode current collector 1, an electrical short circuit between the positive electrode 11 and the negative electrode 12 can be prevented. In other words, the covering material is positioned between the exposed positive electrode current collector 1 and negative electrode current collector 7. The covering material is applied so as to cover the end portions of the positive electrode active agent layer 2 and the negative electrode mixture layer 6 formed on the positive electrode current collector 1 and the negative electrode current collector 7, respectively. A covering material is not disposed at the extreme ends of the positive electrode current collector 1 and the negative electrode current collector 7, and a short circuit between the electrodes is prevented by disposing the covering material on the opposing current collector.

  In the example shown in FIG. 1, the covering materials 10 a and 10 b are disposed at the end of the positive electrode current collector 1 on the winding start side where the positive electrode current collector 1 is exposed, and the negative electrode on the side facing the most end portion. The current collector 7 is provided with coating materials 10c and 10d. The covering material 10 a also covers the lead terminals 8. Further, covering materials 10e and 10f are provided on the positive electrode current collector 1 on the side facing the end of the negative electrode current collector 7 on the winding end side where the negative electrode current collector 7 is exposed.

  Further, this lithium ion polymer secondary battery has an outermost outer periphery on the winding end side because the exposed portion of the end portion of the positive electrode current collector 1 on the winding end side is close to the winding end end of the negative electrode current collector 7. A covering material 10 g is provided at the end of the positive electrode current collector 1 on the surface. By these covering materials 10a, 10b, 10c, 10d, 10e, 10f, and 10g, the portion where each is disposed is protected from a short circuit between both electrodes. Thereby, even if a pressing force is applied to the laminated structure from the outside, the positive electrode 11 and the negative electrode 12 are prevented from being electrically short-circuited.

  Here, the covering material is omitted from the end of the negative electrode current collector 7 on the side where the lead terminals 9 are joined. This is because, as shown in FIG. 1, since the negative electrode current collectors 7 are only facing each other in this portion, even if a short circuit is caused over such a negligible short distance, the electromotive capacity as a battery is reduced. Because there is virtually no adverse effect.

  The covering materials 10a, 10b, 10c, 10d, 10e, 10f, and 10g are arranged so that the thickness of the battery when the positive electrodes 11 and the negative electrodes 12 are alternately stacked is uniform. Here, the relationship between the laminated structure and the arrangement of the covering material will be described in detail. In the lithium ion polymer secondary battery shown in FIG. 1, the pair of the positive electrode and the negative electrode described above is laminated in a total of three layers, that is, an odd number layer, at a position overlapping the lead terminal 9 in the winding cross section. In the case of this winding structure, the position of the electromotive part end on the winding start side, the position of the electromotive part end on the winding end side, and the arrangement of the covering material are shown in FIG. Thus, the battery thickness when the positive electrode 11 and the negative electrode 12 are alternately laminated is made uniform, and the volume energy density is increased. Note that the electromotive portion refers to a portion where an electromotive force is generated in which the positive electrode 11 and the negative electrode 12 are overlapped with each other through the electrolyte 13.

  The formation end portions of the positive electrode active agent layer 2 on both sides of the positive electrode current collector 1 serving as the electromotive portion end on the winding start side are on the upper side, that is, the positive electrode current collector 1 and the negative electrode current collector 7 shown in FIG. Are overlapped with the lead terminal 8 on the side folded back first. Thus, by setting the electromotive portion end on the winding start side to a position where both the positive electrode current collector 1 and the negative electrode current collector 7 overlap with the lead terminal 8 on the first folded side, Steps are unlikely to occur, winding can be performed efficiently, and battery capacity can be increased.

  The end portion of the positive electrode active agent layer 2 that becomes the electromotive portion end on the winding start side is the folded portion on the lead terminal 8 side, that is, both the positive electrode current collector 1 and the negative electrode current collector 7 are first folded. The battery capacity can be increased even if it is positioned between the folded portion and the lead terminal 8. Note that the folding portion refers to a range from the folding start position to the folding end.

  As described above, the lead terminal 8 on the side where both the positive electrode current collector 1 and the negative electrode current collector 7 are first folded at the end portion of the positive electrode active agent layer 2 that becomes the electromotive portion end on the winding start side. Is located between the folded portion where the positive electrode current collector 1 and the negative electrode current collector 7 are first folded, and the lead terminal 8, which is effective in averaging the battery thickness. If the end portion of the positive electrode active material layer 2 is provided in the folded portion, the electrode may be cut at this portion due to expansion or contraction of the electrode due to external stress or repeated charging and discharging. The formation end portion of the positive electrode active agent layer 2 serving as the electromotive portion end on the start side is positioned between the folded portion where the positive electrode current collector 1 and the negative electrode current collector 7 are first folded and the lead terminal 8. It is desirable.

  The ends of the electrolyte layer 3, the electrolyte layer 5, and the negative electrode mixture layer 6 on both sides of the positive electrode current collector 1 on the winding start side are positioned closer to the winding start side than the forming end of the positive electrode active agent layer 2. It is configured. The positions of these end portions are determined so that the thickness after lamination approaches uniformly according to the winding end position and the lamination thickness. The separators 4 on both sides of the positive electrode current collector 1 on the winding start side are wound from substantially the same position as the winding start position of the positive electrode current collector 1. In FIG. 1, the formation ends of the electrolyte layer 3, the electrolyte layer 5, and the negative electrode mixture layer 6 on both sides of the positive electrode current collector 1 on the winding start side are connected to the positive electrode current collector 1 and the negative electrode current collector 7. Both are set as the folding start position which is folded back first.

  The formation end portions of the positive electrode active agent layer 2 on both sides of the negative electrode current collector 7 serving as the electromotive portion end on the winding end side are the lower side shown in FIG. 1, that is, the positive electrode current collector 1 and the negative electrode current collector 7. Are overlapped with each other between the lead terminal 8 and the lead terminal 9 on the side that is finally folded back.

  The ends of the electrolyte layer 3 and the electrolyte layer 5 on both sides of the negative electrode current collector 7 on the winding end side are configured to overlap with the formation end of the positive electrode active agent layer 2. The ends of the negative electrode mixture layer 6 on both sides of the negative electrode current collector 7 on the winding end side are configured to be positioned closer to the winding end than the formation end of the positive electrode active agent layer 2. These positions are determined so that the thickness after lamination approaches uniformly according to the winding end position and the lamination thickness. The separators 4 on both sides of the negative electrode current collector 7 on the winding end side are wound to substantially the same position as the winding end position of the negative electrode current collector 7.

  In the case of this wound structure, the laminated thickness on the lead terminal 8 side becomes thinner than the laminated thickness on the lead terminal 9 side, and a step is generated between the two lead terminals. Therefore, the covering materials 10c, 10d, 10e, and 10f other than the covering material 10a and the covering material 10b provided on the positive electrode current collector 1 on which the lead terminal 8 on the winding start side is formed are configured to overlap the lead terminal 8. is doing. Specifically, the steps are eliminated by arranging the covering materials 10 a, 10 b, 10 c, 10 d, 10 e, 10 f, and 10 g so as to all overlap the lead terminals 8. For example, the covering material 10 c and the covering material 10 d provided on the negative electrode current collector 7 on the winding start side are arranged so as to overlap the lead terminal 8. Further, the covering materials 10 a, 10 b, 10 c, 10 d, 10 e, 10 f, and 10 g are arranged so as not to overlap the lead terminal 9. The arrangement of the covering material shown in FIG. 1 is an example, and the thickness between the lead terminals 8 can be increased by other arrangements according to the end positions of the respective layers to eliminate the step between the two terminals. is there.

  As described above, according to the electrode laminated battery according to the first embodiment of the present invention, both the positive electrode current collector 1 and the negative electrode current collector 7 are folded first at the electromotive portion end on the winding start side. The lead terminal 8 and the lead terminal 9 on the side where the positive electrode current collector 1 and the negative electrode current collector 7 are finally folded together are positioned so as to overlap the lead terminal 8 on the side where the winding is finished. By arranging the covering materials 10a, 10b, 10c, 10d, 10e, 10f, and 10g for preventing the electrical short circuit between the electrodes so as to overlap the lead terminal 8, the step difference due to the lamination Can be eliminated, the thickness can be averaged, and the battery capacity can be increased.

  In the first embodiment, a battery in which a pair of a positive electrode and a negative electrode exists for an odd number of layers at a position overlapping the lead terminal 9 in the winding cross section has been described. The appropriate arrangement varies depending on the position on the winding start side and the position on the winding end side that determines the number of layers in the set. In the following second embodiment, a description will be given of an electrode laminated battery having a structure in which a pair of a positive electrode and a negative electrode exists in an even number of layers at a position overlapping the lead terminal 9 in the above-described winding cross section. In addition, since each member which comprises the laminated structure demonstrated by 2nd Embodiment is the same as that of 1st Embodiment mentioned above except for positional relationship, the same code | symbol is attached | subjected to the same or corresponding part. And simplify the description.

  FIG. 3 shows an example of a schematic configuration of a lithium ion polymer secondary battery in which electrodes are stacked by winding. The lithium ion polymer secondary battery shown in FIG. 3 has a configuration in which a positive electrode and a negative electrode are alternately stacked by winding. The positive electrode is composed of a positive electrode current collector 1 and a positive electrode active agent layer 2 formed on the positive electrode current collector 1. The negative electrode is composed of a negative electrode current collector 7 and a negative electrode mixture layer 6 formed on the negative electrode current collector 7. The electrolyte is separated into a positive electrode side electrolyte layer 3 and a negative electrode side electrolyte layer 5 by a separator 4. Moreover, it has the lead terminal 8 on the positive electrode side and the lead terminal 9 on the negative electrode side, and the covering materials 10a, 10b, 10c, 10d, 10e, and 10f as its main structure.

  In FIG. 3, in order to simplify the illustration, the laminated structure is wound around about twice so that the lead terminal 8 and the lead terminal 9 are located closer to the center. Needless to say, it may actually be wound more times. However, the winding start portion and the end portion of each layer are the same as the positional relationship shown in FIG. The details of the structure of the lead terminal 8 and the lead terminal 9 and the layered portion have been described with reference to FIG. 2 in the first embodiment described above, and are therefore omitted here.

  In the case of the lithium ion polymer secondary battery having the configuration shown in FIG. 3, the pair of the positive electrode and the negative electrode is 2.5 (on the lead terminal 9) +1.5 (on the lead terminal 9). Below) = 4 layers exist.

  In this lithium ion polymer secondary battery, a positive electrode current collector 1 coated with a positive electrode active agent layer 2 and a negative electrode current collector 7 coated with a negative electrode mixture layer 6 are provided, with a positive electrode 11 on the outer side and a negative electrode 12 on the inner side. Thus, the positive electrode 11 and the negative electrode 12 are alternately laminated. More specifically, the lead terminal 8 provided at one end of the positive electrode current collector 1 is disposed at one end side in the longitudinal direction of the wound cross section, and the lead terminal 9 provided at one end of the negative electrode current collector 7 is disposed at the wound cross section. The other end side of the positive electrode current collector 1 and the negative electrode current collector so that both the positive electrode current collector 1 and the negative electrode current collector 7 are first turned back on the lead terminal 8 side. The other end side of the body 7 is wound.

  The positive electrode active agent layer 2 is not applied to the positive electrode current collector 1 on the outermost peripheral surface. Further, the negative electrode mixture layer 6 is not applied to the innermost negative electrode current collector 7. Further, the positive electrode active agent layer 2 is not applied to both surfaces of both ends of the positive electrode current collector 1. The negative electrode mixture layer 6 is not applied to both surfaces of both ends of the negative electrode current collector 7. Therefore, the positive electrode active material layer 2 is formed on the positive electrode current collector 1 so that at least a part of the positive electrode current collector 1 is exposed. The negative electrode mixture layer 6 is formed on the negative electrode current collector 7 so that at least a part of the negative electrode current collector 7 is exposed.

  In the covering materials 10a, 10b, 10c, 10d, 10e, and 10f disposed at the respective positions of the positive electrode current collector 1 and the negative electrode current collector 7, a pressing force is applied to the electrode having the laminated structure from the outside. Even when one electrode and the other electrode are in close proximity to each other, they are made of a material having an insulating property for electrically insulating the electrodes. Further, the covering materials 10a, 10b, 10c, 10d, 10e, and 10f are not torn or damaged even when one electrode is deformed by the application of such a pressing force and contacts the other electrode. It has a material and thickness with mechanical strength, and is formed, for example, by adhering a tape made of polyimide or polypropylene to a corresponding portion.

  The positive electrode current collector 1 and the negative electrode current collector 7 are generally formed so as to be longer than the position where the electrolyte 13 is interposed with a margin at the ends thereof. This is because the electrolyte layer 3 and the electrolyte layer 5 can be completely in contact with the electrodes when the laminated structure is formed by applying or adhering the electrolyte layer 3 and the electrolyte layer 5 on the main surface of each current collector. It is to make it. The amount of exposure (protrusion) at the end of the current collector may be further increased due to the displacement of each electrode when a pressing force is applied after the lamination is formed. In addition, since the electrolyte layer 3 and the electrolyte layer 5 are gel-like and easily deformed, when a pressing force is applied to the laminated structure from the outside during manufacturing of the battery and during use as a product, the entire laminated structure is compressed. As a result, the portions exposed from the electrolyte layer 3 and the electrolyte layer 5 at the end of the current collector are in close proximity to each other.

  However, the lithium ion polymer secondary battery may be in contact with the exposed portion of the negative electrode current collector 7 and / or the exposed portion of the negative electrode current collector 7 which may be in contact with the exposed portion of the positive electrode current collector 1. Since the covering material is provided on the exposed portion of a certain positive electrode current collector 1, an electrical short circuit between the positive electrode 11 and the negative electrode 12 can be prevented. In other words, the covering material is positioned between the exposed positive electrode current collector 1 and negative electrode current collector 7. The covering material is applied so as to cover the end portions of the positive electrode active agent layer 2 and the negative electrode mixture layer 6 formed on the positive electrode current collector 1 and the negative electrode current collector 7, respectively. A covering material is not disposed at the extreme ends of the positive electrode current collector 1 and the negative electrode current collector 7, and a short circuit between the electrodes is prevented by disposing the covering material on the opposing current collector.

  In the example shown in FIG. 3, the covering materials 10 a and 10 b are provided at the end of the positive electrode current collector 1 on the winding start side where the positive electrode current collector 1 is exposed, and the negative electrode on the side facing the extreme end. The current collector 7 is provided with coating materials 10c and 10d. The covering material 10 a also covers the lead terminals 8. Further, covering materials 10e and 10f are provided on the positive electrode current collector 1 on the side facing the end of the negative electrode current collector 7 on the winding end side where the negative electrode current collector 7 is exposed. These covering materials 10a, 10b, 10c, 10d, 10e, and 10f protect the portion where each is disposed from a short circuit between both electrodes. Thereby, even if a pressing force is applied to the laminated structure from the outside, the positive electrode 11 and the negative electrode 12 are prevented from being electrically short-circuited.

  Here, the covering material is omitted from the end of the negative electrode current collector 7 on the side where the lead terminals 9 are joined. This is because, as shown in FIG. 3, since the negative electrode current collectors 7 are only facing each other in this part, even if a short circuit is caused over such a negligible short distance, the electromotive capacity as a battery is reduced. Because there is virtually no adverse effect.

  The covering materials 10a, 10b, 10c, 10d, 10e, and 10f are arranged so that the thickness of the battery is uniform when the positive electrodes 11 and the negative electrodes 12 are alternately stacked. Here, the relationship between the laminated structure and the arrangement of the covering material will be described in detail. In the lithium ion polymer secondary battery shown in FIG. 3, a total of four pairs of positive and negative electrodes, that is, even layers, are stacked at positions overlapping the lead terminals 9 in the winding cross section. In the case of this winding structure, the position of the electromotive part end on the winding start side, the position of the electromotive part end on the winding end side, and the arrangement of the covering material are shown in FIG. Thus, the battery thickness when the positive electrode 11 and the negative electrode 12 are alternately laminated is made uniform, and the volume energy density is increased.

  The formation end portions of the positive electrode active agent layer 2 on both sides of the positive electrode current collector 1 serving as the electromotive portion end on the winding start side are the upper side shown in FIG. 3, that is, the positive electrode current collector 1 and the negative electrode current collector 7. Are overlapped with the lead terminal 8 on the side folded back first. Thus, by setting the electromotive portion end on the winding start side to a position where both the positive electrode current collector 1 and the negative electrode current collector 7 overlap with the lead terminal 8 on the first folded side, Steps are unlikely to occur, winding can be performed efficiently, and battery capacity can be increased.

  The end portion of the positive electrode active agent layer 2 that becomes the electromotive portion end on the winding start side is the folded portion on the lead terminal 8 side, that is, both the positive electrode current collector 1 and the negative electrode current collector 7 are first folded. The battery capacity can be increased even if it is positioned between the folded portion and the lead terminal 8.

  As described above, the lead terminal 8 on the side where both the positive electrode current collector 1 and the negative electrode current collector 7 are first folded at the end portion of the positive electrode active agent layer 2 that becomes the electromotive portion end on the winding start side. Is located between the folded portion where the positive electrode current collector 1 and the negative electrode current collector 7 are first folded, and the lead terminal 8, which is effective in averaging the battery thickness. If the end portion of the positive electrode active material layer 2 is provided in the folded portion, the electrode may be cut at this portion due to expansion or contraction of the electrode due to external stress or repeated charging and discharging. The formation end portion of the positive electrode active agent layer 2 serving as the electromotive portion end on the start side is positioned between the folded portion where the positive electrode current collector 1 and the negative electrode current collector 7 are first folded and the lead terminal 8. It is desirable.

  The ends of the electrolyte layer 3, the electrolyte layer 5, and the negative electrode mixture layer 6 on both sides of the positive electrode current collector 1 on the winding start side are positioned closer to the winding start side than the forming end of the positive electrode active agent layer 2. It is configured. The positions of these end portions are determined so that the thickness after lamination approaches uniformly according to the winding end position and the lamination thickness. The separators 4 on both sides of the positive electrode current collector 1 on the winding start side are wound from substantially the same position as the winding start position of the positive electrode current collector 1. In FIG. 3, the formation ends of the electrolyte layer 3, the electrolyte layer 5, and the negative electrode mixture layer 6 on both sides of the positive electrode current collector 1 on the winding start side are connected to the positive electrode current collector 1 and the negative electrode current collector 7. In both cases, the end position is the first end position.

  The formation end portions of the positive electrode active agent layer 2 on both sides of the negative electrode current collector 7 serving as the electromotive portion end on the winding end side are connected to the lead terminal 9 side, that is, the positive electrode current collector 1 and the negative electrode current collector 7. Both of them are the positions of the folded portions that are folded back last.

  The ends of the electrolyte layer 3 on both sides of the negative electrode current collector 7 on the winding end side are configured to overlap with the formation end of the positive electrode active agent layer 2. The ends of the electrolyte layer 5 and the negative electrode mixture layer 6 on both sides of the negative electrode current collector 7 on the winding end side are configured to be positioned closer to the winding end side than the forming end of the positive electrode active agent layer 2. Yes. These positions are determined so that the thickness after lamination approaches uniformly according to the winding end position and the lamination thickness. The separators 4 on both sides of the negative electrode current collector 7 on the winding end side are wound to substantially the same position as the winding end position of the negative electrode current collector 7.

  In the case of this wound structure, since the laminated thickness on the lead terminal 9 side and the laminated thickness on the lead terminal 8 side are substantially equal, a large step is generated depending on the arrangement position of the covering material. Therefore, the covering materials 10c, 10d, 10e, and 10f other than the covering material 10a and the covering material 10b provided on the positive electrode current collector 1 on which the lead terminal 8 on the winding start side is formed do not overlap the lead terminal 8. It is composed. Specifically, a set of the covering material 10a and the covering material 10b sandwiching the positive electrode current collector 1 in a portion where the arrangement lead terminal 8 is formed, a set of the covering material 10c and the covering material 10d in other portions, and a covering The steps are reduced by arranging the pair of the material 10e and the covering material 10f so as not to overlap each other. For example, the covering material 10 c and the covering material 10 d provided on the negative electrode current collector 7 on the winding start side are arranged so as not to overlap the lead terminal 8. Further, the covering materials 10 a, 10 b, 10 c, 10 d, 10 e, and 10 f are arranged so as not to overlap the lead terminal 9. In addition, arrangement | positioning of this coating | covering material shown in FIG. 3 is an example, and it is also possible to reduce the level | step difference by lamination | stacking by the other arrangement | positioning according to the edge part position of each layer.

  As described above, according to the electrode laminated battery according to the second embodiment of the present invention, both the positive electrode current collector 1 and the negative electrode current collector 7 are folded first at the electromotive portion end on the winding start side. The electrode terminal on the winding end side is the position of the folded portion where the positive electrode current collector 1 and the negative electrode current collector 7 are finally folded, By arranging the set of the covering material 10a and the covering material 10b to prevent the electrical short circuit, the set of the covering material 10c and the covering material 10d, and the set of the covering material 10e and the covering material 10f so as not to overlap each other. It is possible to increase the battery capacity by reducing the level difference due to lamination and averaging the thickness.

  Here, the results of comparing the thicknesses and efficiencies of the lithium ion polymer secondary batteries when the laminated structures described in the first and second embodiments and the other laminated structures are actually produced are described. To do. The lithium ion polymer secondary battery was manufactured to have a thickness of 3.8 mm, a width of 35 mm, and a height of 62 mm.

  The separator 4 had a thickness of 9 μm and a total length of 1.2 m. The insulating covering material having a thickness of 30 μm was used. The lead terminal 8 and the lead terminal 9 have a width of 4 mm and a thickness of 70 μm.

  FIG. 4 shows the structure of the electrode used for winding in the stretched state. FIG. 4A shows a structure on the positive electrode side, and FIG. 4B shows a structure on the negative electrode side. The electrode having the shape shown in FIG. 4 was wound to produce a lithium ion polymer secondary battery.

  In FIG. 4A, X is the length of the positive electrode active agent layer 2 formed on the wound inner surface of the positive electrode current collector 1, and Y is the positive electrode activator formed on the wound outer surface of the positive electrode current collector 1. It is the length of the layer 2, and Z is the length from the end portion of the positive electrode active agent layer 2 on the winding start side to the lead terminal 8. 4B, x is the length of the negative electrode mixture layer 6 formed on the wound inner surface of the negative electrode current collector 7, and y is the negative electrode mixture formed on the wound outer surface of the negative electrode current collector 7. It is the length of the layer 6, and z is the length from the end portion of the negative electrode mixture layer 6 on the winding start side to the lead terminal 9. The dimensions of these X, Y, Z and x, y, z were adjusted to form a laminated structure of the following Example 1 and Example 2, and Comparative Examples 1 to 4. The reference positions of X, Y, and Z are the positions of the end portions of the positive electrode active agent layer 2 on the winding start side. Further, the reference position of x and z is the position of the forming end portion of the negative electrode mixture layer 6 on the winding start side, and the reference position of y is the forming end of the negative electrode mixture layer 6 on the winding end side thereby. The position of the part.

Example 1
As an example of a laminated structure in which a pair of positive and negative electrodes exists for the odd number of layers at positions overlapping with the lead terminals 9, the lengths of X, Y, and Z are set to 375 mm, 303 mm, and 7 mm, respectively, and x, y, z The lengths of 378 mm, 317 mm, and 34 mm, respectively, produced a lithium ion polymer secondary battery having the laminated structure and covering material arrangement described in the first embodiment shown in FIG.

(Comparative Example 1)
As an example of a laminated structure in which a pair of positive and negative electrodes exists in an amount overlapping with the lead terminals 9, the lengths of X, Y, and Z are 382 mm, 311 mm, and 7 mm, respectively, and x, y, z Were made to be 386 mm, 323 mm, and 34 mm, respectively, to produce a lithium ion polymer secondary battery having the laminated structure and the coating material arrangement shown in FIG.

  As shown in FIG. 5, the lithium ion polymer secondary battery of Comparative Example 1 has a long electrode length, and the position of the electromotive portion end on the winding end side is a position overlapping the lead terminal 8. 1 is substantially the same structure as the lithium ion polymer secondary battery according to the first embodiment shown in FIG.

(Comparative Example 2)
As an example of a laminated structure in which a pair of positive and negative electrodes exists for the odd number of layers at positions overlapping with the lead terminals 9, the lengths of X, Y, and Z are set to 375 mm, 303 mm, and 7 mm, respectively, and x, y, z Were made 378 mm, 317 mm, and 34 mm, respectively, to produce a lithium ion polymer secondary battery having the laminated structure and the coating material arrangement shown in FIG.

  As shown in FIG. 6, the lithium ion polymer secondary battery of Comparative Example 2 is arranged on the lead terminal 9 side so that the covering material 10c and the covering material 10d do not overlap the lead terminal 8 but overlap the lead terminal 9. Except for this, the structure is almost the same as that of the lithium ion polymer secondary battery according to the first embodiment shown in FIG.

  FIG. 7 shows data such as battery capacity, battery thickness (lead terminal 8 side and lead terminal 9 side) and volume energy density obtained from the batteries produced in Example 1 and Comparative Examples 1 and 2. It is a summary.

  As shown in FIG. 7, in the battery of Example 1, the thickness of the lead terminal 8 portion and the lead terminal 9 portion is almost uniform, and it can be seen that both the battery capacity and the volume energy density are good. . On the other hand, as shown in FIG. 5, the battery of Comparative Example 1 has a high battery capacity, but the thickness averaging is lost, and the battery thickness on the lead terminal 8 side is 3.97 mm, which exceeds the allowable range. I'm stuck. It can be seen that the volume energy density is low due to the swelling on the lead terminal 8 side. In addition, the battery of Comparative Example 2 has good battery capacity and volume energy density. However, since the covering material 10c and the covering material 10d are arranged at the position overlapping the lead terminal 9, the corresponding amount (the thickness of the insulating tape) It can be seen that the thickness of the battery on the lead terminal 9 side is increased by the amount of 2 sheets), the thickness averaging is broken, and the volume energy density is slightly low.

  In a laminated structure in which a pair of positive and negative electrodes is present in an odd number of layers at positions overlapping with the lead terminals 9 as shown in FIG. 1, the tape is disposed on the positive electrode current collector 1 and the negative electrode current collector 7. Since all the covering materials such as the above are arranged on the lead terminal 8 side, the thicknesses on the lead terminal 8 side and the lead terminal 9 side cannot be averaged depending on the thickness of the electrode and the thickness of the covering material. Will occur.

  The lithium ion polymer secondary battery fabricated this time uses a 30 μm-thick coating material, which is almost a 30 × 8 = 240 μm-thick coating material with a pair of positive and negative electrode pairs. It will be a form that compensates for this.

  Therefore, when the thickness of the combination of the positive electrode and the negative electrode is considerably larger than the numerical value, that is, 240 μm, it is difficult to average the thickness and a step is generated. Therefore, it is desirable to determine the thickness of the covering material according to the thickness of the combination of the positive electrode and the negative electrode. For example, in this case where a coating material having a thickness of 30 μm is used, the thickness of the combination of the positive electrode and the negative electrode is preferably 280 μm or less. For example, when the thickness of the combination of the positive electrode and the negative electrode is 300 μm, it is desirable to use a coating material having a thickness of 50 μm. As shown in FIG. 3, for the laminated structure in which a pair of positive and negative electrodes exists for an even number of layers, since the coating material is scattered, the thickness of the coating material is set to the combination of the positive electrode and the negative electrode. It may not be determined according to the thickness.

(Example 2)
As an example of a laminated structure in which a pair of positive and negative electrodes exist for even layers at positions overlapping the lead terminals 9, the lengths of X, Y, and Z are 424 mm, 354 mm, and 7 mm, respectively, and x, y, z Were made 429 mm, 396 mm, and 34 mm, respectively, to produce a lithium ion polymer secondary battery having the laminated structure and the arrangement of the covering materials described in the second embodiment shown in FIG.

(Comparative Example 3)
As an example of a laminated structure in which a pair of positive and negative electrodes exists in an amount overlapping with the lead terminal 9, the lengths of X, Y, and Z are 410 mm, 340 mm, and 7 mm, respectively, and x, y, z Were made to be 415 mm, 382 mm, and 34 mm, respectively, to produce a lithium ion polymer secondary battery having the laminated structure and the coating material arrangement shown in FIG.

  As shown in FIG. 8, in the lithium ion polymer secondary battery of Comparative Example 3, the electrode length was changed, and the position of the electromotive portion end on the winding end side was folded back on the lead terminal 8 side. 3 is substantially the same structure as the lithium ion polymer secondary battery according to the second embodiment shown in FIG.

(Comparative Example 4)
As an example of a laminated structure in which a pair of positive and negative electrodes exists in an amount overlapping with the lead terminals 9, the lengths of X, Y, and Z are 435 mm, 365 mm, and 7 mm, respectively, and x, y, z Were made 439 mm, 406 mm, and 34 mm, respectively, to produce a lithium ion polymer secondary battery having the laminated structure and covering material arrangement shown in FIG.

  As shown in FIG. 9, in the lithium ion polymer secondary battery of Comparative Example 4, the electrode length is changed, and the position of the electromotive portion end on the winding end side is turned back on the lead terminal 9 side. 3 is substantially the same structure as the lithium ion polymer secondary battery according to the second embodiment shown in FIG.

  FIG. 10 summarizes data such as the capacity of each battery, the thickness of the battery, and the volume energy density obtained from the batteries prepared in Example 2 and Comparative Examples 3 and 4.

  As shown in FIG. 10, in the battery of Example 2, the thicknesses of the lead terminal 8 side and the lead terminal 9 side are almost uniform, and it can be seen that both the battery capacity and the volume energy density are good. On the other hand, in the battery of Comparative Example 3, only the thickness on the lead terminal 9 side is thin, the thickness on the lead terminal 8 side is not changed, the thickness as the battery is not changed, the electrode length is short, and the battery capacity is low, It can be seen that the volume energy density is also low. Further, although the battery of Comparative Example 4 has a long electrode length and a high battery capacity, since the combination of a pair of positive electrode and negative electrode overlaps the lead terminal 9, the thickness of the battery on the lead terminal 9 side is 3.92 mm. And it has exceeded the allowable range. It can be seen that due to the swelling on the lead terminal 9 side, the average thickness is broken and the volume energy density is slightly low.

  From the above comparison results, it can be seen that in the lithium ion polymer secondary battery according to the first and second embodiments described above, the thickness of the battery can be averaged and the battery capacity can be obtained efficiently. . Although not manufactured this time, when the covering material 10c and the covering material 10d provided on the negative electrode current collector 7 on the winding start side are provided on the lead terminal 8 or the lead terminal 9 side, the lead terminal 8 is provided. The lead terminal 9 side becomes thicker by the thickness of the covering material 10c and the covering material 10d, and the volume energy density decreases.

  The present invention is not limited to the above-described embodiments of the present invention, and various modifications and applications are possible without departing from the spirit of the present invention. For example, in the above-described embodiment, the flat type battery in which the electrode is wound in a parabolic shape has been described. However, the present invention is not limited to this, and a cylindrical battery that is wound in a cylindrical shape or a rectangular battery that is wound in a rectangular shape. You may apply to. In addition, the electrode stacking is not limited to the winding method but can be applied to a battery of a stacking method or a bending method.

  Further, in the above-described embodiment, the lithium ion polymer secondary battery in which the electrolyte is a gel is described as an example of the electrode laminated battery. However, the present invention is not limited to this, and if the battery has a schematic configuration as described above, The present invention can also be applied to a primary battery that is not charged and redischarged, a lithium ion secondary battery in which the electrolyte is liquid, and the like. For example, even if the electrolyte layer is made of a material other than the polymer solid electrolyte, any material can be used as long as the material is a gel-like or plastic electrolyte or an electrode made of a flexible material. Even such a thing is applicable. Or it cannot be overemphasized that the material of a positive electrode or a negative electrode, the metal material used for a lead electrode, etc. are not limited only to what was shown in the embodiment mentioned above.

  In the above-described embodiment, polyimide tape is used as the covering material. However, the insulating material is formed on the corresponding portion so that the covering material has the insulating property and the mechanical strength as described above. It may be what you did.

It is a basic diagram which shows an example of schematic structure of the lithium ion polymer secondary battery by 1st Embodiment of this invention. It is an enlarged view of the lamination | stacking part of the lithium ion polymer secondary battery by 1st Embodiment. It is a basic diagram which shows an example of schematic structure of the lithium ion polymer secondary battery by 2nd Embodiment of this invention. It is a basic diagram of an example which shows the structure of the electrode to wind. It is a basic diagram which shows an example of schematic structure of the lithium ion polymer secondary battery used for the comparison. It is a basic diagram which shows an example of schematic structure of the lithium ion polymer secondary battery used for the comparison. Data such as battery capacity, battery thickness and volumetric energy density are summarized. It is a basic diagram which shows an example of schematic structure of the lithium ion polymer secondary battery used for the comparison. It is a basic diagram which shows an example of schematic structure of the lithium ion polymer secondary battery used for the comparison. Data such as battery capacity, battery thickness and volumetric energy density are summarized.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Positive electrode collector, 2 ... Positive electrode active material layer, 3 ... Positive electrode side electrolyte layer, 4 ... Separator, 5 ... Negative electrode side electrolyte layer, 6 ... Negative electrode mixture layer 7 ... Negative electrode current collector, 8 ... Positive electrode side lead terminal, 9 ... Negative electrode side lead terminal, 10a, 10b, 10c, 10d, 10e, 10f, 10g ... Covering material, 11 ... -Positive electrode, 12 ... negative electrode, 13 ... electrolyte

Claims (4)

In the electrode laminate type battery having a structure in which the positive electrode and the negative electrode are alternately laminated via an electrolyte, and the lamination is performed by winding the positive electrode and the negative electrode .
The positive electrode is composed of a positive electrode current collector and a positive electrode active agent layer formed on the positive electrode current collector so that at least a part of the positive electrode current collector is exposed,
The negative electrode is composed of a negative electrode current collector and a negative electrode mixture layer formed on the negative electrode current collector so that at least a part of the negative electrode current collector is exposed,
Insulating the exposed portion of the negative electrode current collector and / or the exposed portion of the negative electrode current collector that may be in contact with the exposed portion of the positive electrode current collector Coating material is provided,
The dressing so that the thickness at the time of alternately laminated the positive electrode and the negative electrode is uniform are arranged,
A positive electrode lead terminal provided at one end of the positive electrode current collector is disposed at one end side in the longitudinal direction of the wound cross section, and a negative electrode lead terminal provided at one end of the negative electrode current collector is disposed at the other end in the longitudinal direction The other end side of the positive electrode current collector and the negative electrode current collector is connected to the positive electrode so that both the positive electrode current collector and the negative electrode current collector are first folded on the positive electrode lead terminal side. Winding so that the negative electrode is on the outside and the negative electrode is on the inside, the position of the electromotive portion end on the winding start side overlaps with the positive electrode lead terminal on the first folded side, or the first folded portion And an electrode laminated battery positioned between the positive electrode lead terminal and the positive electrode lead terminal . In claim 1 ,
When a pair of positive electrodes and negative electrodes exist in an odd number layer at a position overlapping with the negative electrode lead terminal, the position of the electromotive portion end on the winding end side is determined as the positive electrode current collector and the negative electrode current collector. Between the positive electrode lead terminal and the negative electrode lead terminal on the last folded side, so that the coating material other than the coating material provided on the positive electrode current collector on the winding start side overlaps the positive electrode lead electrode. arranged in which electrodes stacked battery in. In claim 1 ,
When a pair of positive electrodes and negative electrodes exists in an amount overlapping with the negative electrode lead terminal, the position of the electromotive portion end on the winding end side is determined as the positive electrode current collector and the negative electrode current collector. DOO both the folded portion which is folded back at the end, the winding start side of the positive electrode current collector to provided a coating material other than the covering material the positive electrode lead electrode does not overlap so arranged to have electrodes stacked battery . In claim 1,
The electrolyte is an electrode-stacked battery composed of a gel polymer in which an electrolyte is dispersed in a polymer matrix.

Images