JP2013069527A - Secondary battery, electrode for secondary battery, and method and apparatus for manufacturing secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode, a secondary battery using the same, and a method and an apparatus for manufacturing the same, capable of preventing an internal short circuit when the internal short circuit occurs due to contacting of a negative electrode (positive electrode) with burrs formed on a periphery of the positive electrode (negative electrode) through a separator.SOLUTION: A resin R of insulating substance is applied on a positive electrode 2. The positive electrode 2 includes an abutting surface 2a abutted against a positive electrode collector 6 and an opposing surface 2b of an opposite side-surface of the positive electrode 2, where a resin R is applied on the opposing surface 2b. The burrs may be formed outward from a surface or periphery of the opposing surface 2b (B1, B2). Therefore, an end of the positive electrode 2 is holed by pressing means to cause the burr B2 to be bent inward of the opposing surface 2b before the resin is applied on the opposing surface 2b of the positive electrode 2. Then the resin is applied on the opposing surface 2b with the burr B2 to constitute the resin R2.

Description

  The present invention relates to a secondary battery, an electrode for a secondary battery, a method for manufacturing a secondary battery, and a manufacturing apparatus.

  Conventionally, secondary batteries have been used in various products such as mobile phones, mobile personal computers, power tools, and power-assisted bicycles. Recently, hybrid vehicles using both gasoline and batteries have become widespread. In recent years, secondary batteries are also used for power storage using natural energy such as wind power generation and solar power generation. This is because electric power is supplied from the secondary battery stored at the peak of electric power use, the large output portion is supplemented by the secondary battery, and the fluctuating electric power use is smoothed. In this way, secondary batteries have been installed in small bicycles and medium-sized bicycles and automobiles. The number and capacity of the batteries used vary depending on the application, and the capacity and output are increasing. Recently, it has been known that a large-capacity secondary battery is mounted on a vehicle such as an electric car or a train.

  Nickel metal hydride secondary batteries are widely used for such high-capacity secondary batteries mounted on such vehicles in terms of high output, high energy density, voltage stability, safety, and the like.

  Conventional nickel-metal hydride secondary batteries are mainly cylindrical batteries and prismatic batteries. A cylindrical battery includes an electrode body formed by winding a sheet-like positive electrode and a sheet-like negative electrode with a separator interposed in a cylindrical battery container. In addition, the rectangular battery includes an electrode body in which a plurality of strip-shaped positive electrodes and negative electrodes are alternately stacked via separators in a rectangular battery container together with an electrolytic solution. In any battery, the positive electrode and the negative electrode are in close contact via a separator.

  Usually, electrodes (positive electrode and negative electrode) are produced in a large area, and then formed into a predetermined shape by a slitter, a cutter or the like. For this reason, a burr | flash may be formed in the cut end surface of an electrode. Although such burrs are generally minute, if the burrs formed on the positive electrode are formed so as to protrude toward the outside of the electrode, they penetrate through the adjacent separator and are physically connected to the negative electrode to cause a short circuit. May occur.

  Therefore, it is an important issue to establish a technique for preventing a short circuit inside the battery.

  As a technique for preventing such a short circuit due to burrs, an invention in which inactive materials are provided at both ends in the longitudinal direction of the positive electrode is disclosed (see, for example, FIG. 1 of Patent Document 1). Moreover, the invention which provided the inactive material in the longitudinal direction both ends of the positive electrode so that a burr | flash might be coat | covered is disclosed (for example, refer FIG. 6 of patent document 1).

Japanese Patent Laid-Open No. 2004-55537

  As described above, in the conventional secondary battery, the positive electrode and the negative electrode may be in physical contact with each other by the burrs formed on the cut end surfaces of the positive electrode and the negative electrode, thereby causing a short circuit.

  On the other hand, in the invention described in FIG. 1 of Patent Document 1, since inactive material portions are provided at both ends of the electrode, leads for taking out electricity from the electrode are indispensable, resulting in increased resistance and loss. Moreover, since the both ends of an electrode are covered with an inactive material, manufacture of an electrode becomes complicated. Furthermore, in this invention, since the burr | flash which protruded toward the outer side from the cut end surface of an electrode is not covered with the inactive material, a short circuit cannot be prevented. In other words, it is impossible to deal with burrs protruding toward the separator.

  In addition, in the invention described in FIG. 6 of Patent Document 1, since the inactive material portion is provided so as to cover the end portion of the electrode, the width of the end portion of the electrode becomes thick, and a plurality of electrodes are stacked. Hinder. That is, the number of stacked electrodes is reduced by the thickness of the insulating material, and the battery capacity is reduced. Also, in the case of a wound battery, the number of times of winding may be reduced, and there may be a deviation in electrode arrangement.

  One of the objects of the present invention is to provide a secondary battery, a secondary battery electrode, a secondary battery manufacturing method and manufacturing apparatus, and an end burr that efficiently treat the burr at the end of the electrode to prevent a short circuit. It is an object to provide an electrode that is efficiently processed.

  Another object is to provide a secondary battery, a secondary battery electrode, a secondary battery manufacturing method, and a manufacturing apparatus capable of dealing with burrs protruding outward from the cut end face of the electrode.

  In order to achieve the above object, the secondary battery according to claim 1 of the present invention is such that electrode bodies having a structure in which a sheet-like positive electrode and a sheet-like negative electrode are stacked with a separator interposed therebetween face each other. The positive electrode current collector and the negative electrode current collector are disposed between the positive electrode current collector and the negative electrode current collector. The positive electrode is disposed at one end in the opposite direction of the current collector, and the negative electrode is disposed at the opposite one end. The electrodes are overlapped with each other so as to protrude in a state of being shifted in the facing direction of the current collector, and the positive electrode and the negative electrode are respectively contacted with the current collector at one end on the protruding side. And at least one of the positive electrode and the negative electrode has an insulating portion in which an insulating material is disposed on the other end opposite to the protruding side. .

  According to this configuration, one end of the positive electrode and the negative electrode (hereinafter referred to as “contact surface”) is in contact with the positive electrode current collector or the negative electrode current collector, and the other end (hereinafter referred to as “opposite surface”). Since an insulating material is applied to the surface, short-circuiting caused by burrs protruding from the opposite surface of the positive electrode or the negative electrode can be suppressed. In addition, the present invention may be applied only to an electrode that is likely to generate burrs among the positive electrode and the negative electrode, or may be applied to both the positive electrode and the negative electrode (note that the positive electrode and the negative electrode are collectively referred to as “electrode”, The positive electrode current collector and the negative electrode current collector may be collectively referred to as “current collector”).

  Here, the “burr” refers to a minute protrusion on the cut end surface that is formed when an electrode material is cut into a predetermined shape with a slitter, a cutter, or the like. Further, the size of the burr can be variously considered depending on the size of the positive electrode or the negative electrode or the cut size, but most are in the range of 0.1 to 0.5 mm and sometimes in the range of 0.1 mm or less. .

  The “sheet-like positive electrode and sheet-like negative electrode” are, for example, a sheet-like positive electrode or negative electrode having flexibility, for example, a substantially strip-like sheet-like positive electrode or negative electrode.

  The insulating material may be a resin such as an ethylene / vinyl acetate copolymer (EVA), polypropylene (PP), or polyethylene (PE).

  In addition, since one end portion of the electrode functions as a contact surface that comes into contact with the positive electrode current collector or the negative electrode current collector, a lead for taking out electricity is unnecessary, and electricity can be taken out efficiently. Furthermore, since it is not necessary to apply an insulating material to both ends of the electrode, it is easy to manufacture the electrode.

  In the secondary battery according to claim 2, the burr at the other end is included in the insulating portion.

  Here, that the burr at the other end is included in the insulating part means that an insulating material is applied so as to cover the burr formed there.

  The secondary battery according to claim 3 is characterized in that the burr at the other end does not protrude in the thickness direction of the positive electrode or the negative electrode.

  According to this configuration, it is possible to prevent a burr protruding from the opposite surface of the electrode, particularly a burr protruding from the peripheral edge of the opposite surface toward the outside of the electrode from penetrating the separator. That is, it is possible to prevent a short circuit that occurs when the burr of the electrode comes into contact with the adjacent electrode through the separator. Here, with respect to the burrs protruding toward the outside of the electrode, for example, both sides in the thickness direction of the electrode may be pressed by pressing means, and the burrs may be tilted toward the inside of the opposite surface of the electrode.

  The secondary battery according to claim 4 is characterized in that the insulating portion has a width equal to or smaller than a width dimension of the other end portion and is formed along a longitudinal direction of the other end portion.

  According to this configuration, since the insulating portion does not protrude from the opposite surface of the electrode and the thickness of the electrode is not different from the conventional one, in the case of a battery in which a plurality of electrodes are stacked, the number of stacked electrodes does not decrease. Also, in the case of a wound battery, it is not necessary to reduce the number of times of winding, and the displacement of the electrodes is less likely to occur.

  The secondary battery according to claim 5, wherein the electrode body has a plurality of positive electrodes and negative electrodes alternately opposed to each other through the twisted separators in a direction orthogonal to a facing direction of the current collector. Are stacked.

  According to this configuration, even in the case of a laminated battery, it is possible to prevent a short circuit due to burrs. In addition, since the contact surface of the electrode is in contact with and electrically connected to the current collector, electricity can be efficiently taken out, and a short circuit due to burrs on the contact surface hardly occurs. That is, if the burrs on the opposite surface on the separator side are processed, short-circuiting due to burrs can be efficiently suppressed.

  In addition, since the electrode is biased toward the current collector due to the presence of the insulating portion in the electrode, the electrode and the current collector can be brought into firm and reliable contact, and the secondary battery has been used for a long time. Even in this case, it is difficult for these contact surfaces to be displaced, and an increase in contact resistance can be suppressed.

  The secondary battery according to claim 6, wherein the positive electrode and the negative electrode are spirally wound through a separator, and the winding axis is the positive electrode current collector and the negative electrode current collector. It is a direction orthogonal to the opposing direction.

  According to this configuration, a short circuit due to burrs can be prevented even in the case of a wound battery. In addition, since the contact surface of the electrode is in contact with and electrically connected to the current collector, electricity can be taken out efficiently. Furthermore, since the positive electrode and the negative electrode are configured to be shifted so as to protrude to one end portion or the other end portion in the axial direction of the electrode body, a short circuit due to a burr on the contact surface hardly occurs. That is, if the burr on the opposite side is processed, a short circuit due to the burr can be efficiently suppressed.

  In the secondary battery according to claim 7, a plurality of the electrode bodies may be arranged between the current collectors.

  According to this configuration, a large-capacity secondary battery including a plurality of wound electrodes can be obtained.

  9. The electrode according to claim 8, wherein the electrode is a sheet-like positive and negative electrode, and has one end contacting the outer periphery with the positive electrode current collector or the negative electrode current collector, the other end on the opposite side, and the other end. And an insulating part formed by applying an insulating material to the insulating part, and burrs at the other end part do not protrude in the thickness direction of the electrode.

  According to this configuration, it is possible to prevent the burr protruding outward from the opposite surface of the electrode from penetrating the separator. That is, by using this electrode for a secondary battery, it is possible to prevent a short circuit that occurs when a burr contacts an adjacent electrode.

  Here, such an electrode includes, for example, a positive electrode current collector and a negative electrode current collector in which electrode bodies having a structure in which a sheet-like positive electrode and a sheet-like negative electrode are stacked with a separator interposed therebetween. The electrode body is arranged between the electric bodies, and the electrode is arranged such that the positive electrode protrudes from one end portion in the opposite direction of the current collector, and the negative electrode protrudes from the opposite one end portion. The positive electrode and the negative electrode are overlapped in a state of being shifted in the facing direction of the current collector, and at one end portion on the protruding side thereof, are respectively in contact with and electrically connected to the current collector, The present invention can be applied to a positive electrode or a negative electrode of a secondary battery in which at least one of the positive electrode and the negative electrode has an insulating portion in which an insulating material is disposed on the other end opposite to the protruding side.

  The method of manufacturing a secondary battery according to claim 9 includes a sheet-like positive and negative electrode having one end contacting the positive electrode current collector or the negative electrode current collector on the outer periphery and the other end on the opposite side. A pressing process in which the electrode is pressed from both sides in the thickness direction, and the burr at the other end is tilted inward in the thickness direction of the electrode, and an insulating material is provided at the other end. And a coating step of coating.

  According to this configuration, since there is a pressing step for processing burrs protruding outward from the other end (opposite surface) of the electrode and a coating step for applying an insulating material to the opposite surface, A secondary battery capable of preventing burrs protruding outward from the surface from penetrating the separator can be manufactured.

  Further, in the pressing step, in addition to pressing the electrode from both sides in the thickness direction (two directions on the left and right) with a pressing machine, pressing may be performed so as to be inserted from the left, right, and upper three directions. Moreover, it is preferable that the press from two directions on the left and right is tapered in an eight shape so as to spread from the upper side to the lower side. If it does in this way, it will be easy to incline the burr | flash which protruded outward from the opposite surface of the electrode inward of the opposite surface.

  In the method for manufacturing a secondary battery according to claim 10, it is preferable that the electrode is heated in the pressing step.

  According to this configuration, the insulating material can be firmly applied to the electrode. In addition, it is preferable that the temperature of an electrode shall be 50 to 100 degreeC.

  In the method of manufacturing a secondary battery according to claim 11, it is more preferable that the temperature of the electrode is heated to 30 ° C. to 90 ° C. in the pressing step.

  The temperature of the electrode for applying the insulating substance to the electrode is more preferably 30 ° C. to 90 ° C.

  The method of manufacturing a secondary battery according to claim 12 includes means for detecting a start point and an end point of the electrode in the coating step.

  According to this configuration, in the application of the insulating material of the electrode, the insulating material can be reliably applied to the electrode by detecting the start point and the end point of the electrode.

The apparatus for manufacturing a secondary battery according to claim 13 has a sheet-like positive and negative electrode having one end contacting the positive electrode current collector or the negative electrode current collector on the outer periphery and the other end on the opposite side. A secondary battery manufacturing apparatus, which presses the electrode from both sides in the thickness direction and simultaneously heats the electrode to tilt the burr at the other end inward in the thickness direction of the electrode;
It has a sensor which detects the starting point and the end point of an electrode, and provided with the application means which applies an insulating substance to the other end.

  According to this configuration, the burr on the other end (opposite surface) of the electrode can be tilted inward in the thickness direction by a press, and the opposite surface is applied by the coating means having a sensor for detecting the start point and end point of the electrode. It is possible to reliably apply an insulating material. Therefore, a secondary battery including an electrode capable of preventing a short circuit can be manufactured by this manufacturing apparatus.

  As described above, the present invention can efficiently prevent a short circuit due to burrs by applying an insulating material to the opposite surface of the electrode.

1 is a perspective view of a secondary battery according to a first embodiment of the present invention. It is an exploded view of the cell in the secondary battery of FIG. It is sectional drawing of the secondary battery of FIG. 1 is an enlarged perspective view of a positive electrode, a negative electrode plate, and a separator portion of a secondary battery according to a first embodiment of the present invention. It is a perspective view of a positive electrode. FIG. 6 is a partially enlarged perspective view of FIG. 5. It is an expansion perspective view before the burr | flash process of FIG. 6, and resin coating. It is explanatory drawing which shows the manufacturing process of the positive electrode of the secondary battery which concerns on 1st Embodiment of this invention. (A) is the P section enlarged side view of FIG. (B) is the Q section enlarged side view. It is a perspective view of the coating device 16 of FIG. (A) It is a partially broken perspective view of the secondary battery which concerns on 2nd Embodiment of this invention. (B) is sectional drawing of the electrode body of the secondary battery. It is a perspective view of the positive electrode of the secondary battery which concerns on 2nd Embodiment of this invention. It is a partially broken perspective view which shows the modification of the secondary battery which concerns on 2nd Embodiment of this invention.

  Hereinafter, although the embodiment concerning the present invention is described based on a drawing, the present invention is not limited to the following embodiment.

(1) First Embodiment (Structure of Secondary Battery 1)
FIG. 1 is a perspective view of a secondary battery 1 according to the first embodiment of the present invention. The secondary battery 1 is a nickel-hydrogen secondary battery using nickel hydroxide as a main positive electrode active material, a hydrogen storage alloy as a main negative electrode active material, and an alkaline aqueous solution as an electrolyte.

  As shown in the exploded view of FIG. 2, an insulating rectangular frame-shaped member 5 and a rectangular positive electrode which is disposed to face the X-direction so as to cover the frame-shaped member 5 and whose peripheral portion is bent at a substantially right angle. The current collector 6 and the negative electrode current collector 7 constitute a square cell 8. As shown in the cross-sectional view of FIG. 3, inside the cell 8, the positive electrode 2 made of the positive electrode active material, the negative electrode 3 made of the negative electrode active material, and the separator 4 folded in a twisted manner, Are housed together with the electrolyte. The separator 4 is a hydrophilic separator made of a polypropylene nonwoven fabric.

  As shown in the cross-sectional view of FIG. 3, the positive electrode 2 and the negative electrode 3 are stacked in the Y direction perpendicular to the X direction via the separator 4. The contact surface 2 a at one end of the positive electrode 2 is in contact with the positive current collector surface 6 a of the positive electrode current collector 6, and the contact surface 3 a at one end of the negative electrode 3 and the negative electrode current collector 7 of the negative electrode current collector 7 are contacted. The electric surface 7a is in contact with each other. The positive electrode current collector 6 and the negative electrode current collector 7 are formed of nickel-plated steel plates, and the positive electrode 2 and the positive electrode current collector 6 and the negative electrode 3 and the negative electrode current collector 7 are electrically connected to each other. Will be. The surface of the positive electrode current collector 6 opposite to the positive electrode current collector surface 6a is the positive electrode terminal surface 6b, and the surface of the negative electrode current collector 7 opposite to the negative electrode current collector surface 7a is the negative electrode terminal surface 7b. The electric body 6 and the negative electrode current collector 7 also serve as a terminal.

(Structure of positive electrode 2 and negative electrode 3)
FIG. 4 is an enlarged perspective view of the positive electrode 2, the negative electrode 3, and the separator 4. As shown in FIG. 4, the positive electrode 2 and the negative electrode 3 are arranged in a state of being alternately sandwiched between the separators 4 that are bent in a fold-like manner.

  FIG. 5 is a perspective view of the positive electrode 2 (negative electrode 3). As shown in FIG. 5, a resin R is applied to the positive electrode 2. The positive electrode 2 includes a contact surface 2a at one end that contacts the positive electrode current collector 6 and an opposite surface 2b at the other end on the opposite side. The opposite surface 2b is a surface on the side of the cut portion of the separator 4. Resin R is coated on the opposite surface 2b.

  In the present embodiment, the positive electrode 2 is formed in a strip shape having a length of 230 mm, a width of 29 mm, and a width of 0.35 mm, and the width of the resin R is 0.33 mm to 0.35 mm, which is the same as the width of the opposite surface 2b. It is constructed with dimensions or slightly smaller than that. By setting the width of the resin R in this way, it is possible to prevent the resin from protruding from the opposite surface 2b. As a result, the width does not become thicker than that of a conventional positive electrode not coated with resin, and the number of stacked positive electrodes in the secondary battery is not reduced. The height of the resin R is 0.5 mm or less.

  Further, since the positive electrode 2 is manufactured by cutting a sheet-like material into a predetermined shape with a cutter or the like, burrs are formed on the cut end surfaces (the contact surface 2a and the opposite surface 2b) of the positive electrode 2 during cutting. May be formed. The resin R is formed by coating the resin so as to cover the burr B1 on the surface of the opposite surface 2b (see FIG. 6).

  On the other hand, in addition to the burr B1 on the surface of the opposite surface 2b, the burr may be formed outward (Z direction in FIGS. 3 and 7) from the peripheral edge of the opposite surface 2b. Since such a burr B2 is directed to the adjacent negative electrode 3, when such a burr B2 penetrates the separator 4, it contacts with the negative electrode 3 to cause a short circuit. Therefore, before the resin is applied to the opposite surface 2b of the positive electrode 2, the end portion of the positive electrode 2 is sandwiched by pressing means, and the burr B2 is tilted inward of the opposite surface 2b. Thereafter, by applying a resin to the opposite surface 2b, such a burr B2 can be covered, and a short circuit due to contact with the negative electrode 3 can be prevented (see FIG. 6).

  Furthermore, the presence of the resin R allows the burr to contact the resin R of the positive electrode 2 even if a burr formed outward from the peripheral edge of the contact surface 3 a of the negative electrode 3 penetrates the separator 4. Therefore, it is not in direct contact with the positive electrode 2 and a short circuit can be prevented.

  In addition, since the positive electrode 2 is biased toward the positive electrode current collector 6 due to the presence of the resin R, the positive electrode 2 and the positive electrode current collector 6 can be brought into firm and reliable contact with each other. Even when the battery 1 is used for a long period of time, it is difficult for these contact surfaces to be displaced, and an increase in contact resistance can be suppressed.

  The resin application position is not limited to the opposite surface 2b, and may be applied to all surfaces other than the contact surface 2a at the outer peripheral end of the positive electrode 2. Moreover, since the structure of the negative electrode 3 is the same as that of the positive electrode 2, description is abbreviate | omitted.

(Method and apparatus for producing positive electrode 2 and negative electrode 3)
FIG. 8 is a diagram illustrating a manufacturing process of the positive electrode 2 (negative electrode 3).
A) As shown in FIG. 8 (I), a positive electrode 2 obtained by cutting a sheet-like material into a predetermined size by a cutter or the like is held by an electrode adsorption actuator 9, and the end on the opposite surface 2b side is a first press. The positive electrode 2 is conveyed so that it may be located in the 1st press part 11 of the machine 10. FIG.

  B) Next, as shown in FIG. 8 (II), the second press part 12 is operated, the end of the positive electrode 2 is sandwiched between the first press part 11 and the second press part 12, and pressed with a linear pressure of 10 kgf or more. To do. Thereby, the burr | flash B2 protruded outward from the peripheral part of the opposite surface 2b is inclined inward of the opposite surface 2b. In addition, the 1st press part 11 and the 2nd press part 12 are tapered from upper direction to the downward | lower direction, and are comprised by the cross-sectional eight character shape (refer FIG. 9). Moreover, the heater is incorporated in the 1st press machine 10, and the positive electrode 2 is warmed to 30 to 90 degreeC.

  C) As shown in FIG. 8 (III), the positive electrode 2 is transported to the second press machine 13, and the second press machine 13 connects the end of the positive electrode 2 on the abutting surface 2a side with the first press part 14 and the second press machine 13. The positive electrode 2 is held by being sandwiched between the two press portions 15. And in order to transfer to a coating process, the positive electrode 2 is conveyed.

  D) As shown in FIG. 8 (IV), the coating device 16 coats the opposite surface 2b of the positive electrode 2 with the positive electrode 2 held by the second press 13. In addition, since the positive electrode 2 is warmed in the above process, the resin is firmly applied to the positive electrode 2. The coating device 16 includes a storage tank 17 that stores the resin and a nozzle 18 that coats the resin. The nozzle 18 has a coating unit 18a for coating the resin, a first sensor unit 18b for detecting a position for coating the resin, and a second unit for confirming whether or not the resin is reliably coated on the target surface. Sensor portion 18c (see FIG. 10). In this manner, the nozzle 18 moves in the Z direction along the opposite surface 2b, and the resin is applied to the opposite surface 2b in the order of application position detection, resin application, and resin application confirmation.

  E) As shown in FIG. 8 (V), finally, the positive electrode 2 in a state where the resin is applied is cooled by blowing air. By this cooling, the resin is securely fixed to the positive electrode 2. In addition, since the manufacturing method and manufacturing apparatus of the negative electrode 3 are the same as that of the positive electrode 2, description is abbreviate | omitted.

(2) Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is an embodiment in the case where positive and negative electrodes treated with burrs and coated with a resin are applied to a wound battery. The main difference from the first embodiment is the structure of electrodes and separators.

(Structure of secondary battery 101)
FIG. 11 is a cross-sectional perspective view showing the structure of the wound electrode body 105 in the secondary battery 101 of the present invention. As shown in FIG. 11, the substantially cylindrical electrode body 105 includes a sheet-like negative electrode 103, a sheet-like positive electrode 102, and a cloth-like separator 104 that transmits ions and an electrolyte solution interposed between the two electrodes. Prepare. The negative electrode 103 and the positive electrode 102 are wound in a spiral shape in a state where they are overlapped while being shifted up and down via the separator 104, thereby forming an electrode body 105. That is, in the axial direction of the electrode body 105, the upper end of the negative electrode 103 protrudes above the separator 104, and the lower end of the positive electrode 102 protrudes below the separator 104 (see FIG. 11A). Further, in the direction orthogonal to the axial direction of the electrode body 105, the negative electrode 103 and the positive electrode 102 are alternately stacked via the separator 104 from the outer side of the electrode body 105 to the inner side in the radial direction (FIG. 11 (b)).

  The secondary battery 101 is a secondary battery in which the electrode body 105 is accommodated in a substantially cylindrical cell 109. The cell 109 includes a substantially cylindrical frame-shaped member 106, a plate-shaped negative electrode current collector 108 on the upper side, and a plate-shaped positive electrode current collector 107 on the lower side. The frame-shaped member 106 is made of an insulating material. The negative electrode current collector 108 and the positive electrode current collector 107 are made of nickel-plated steel plates. The insulating material used for the frame-shaped member 106 may be a nonwoven fabric such as a separator or an alkali-resistant tape.

  The electrode body 105 is accommodated in the frame-shaped member 106. Further, the upper end portion of the negative electrode 103 is in contact with the negative electrode current collector surface 108 a (not shown) of the negative electrode current collector 108, and the lower end portion of the positive electrode 102 is the positive electrode current collector surface 107 a (not shown) of the positive electrode current collector 107. ), And the negative electrode 103, the negative electrode current collector 108, the positive electrode 102, and the positive electrode current collector 107 are electrically connected. The surface of the negative electrode current collector 108 opposite to the negative electrode current collector surface 108a is a negative electrode terminal surface 108b (not shown), and the surface of the positive electrode current collector 107 opposite to the positive electrode current collector surface 107a is the positive electrode terminal surface. 107b (not shown).

  In addition, the negative electrode 103 and the positive electrode 102 protruding above and below the electrode body 105 are only in contact with the negative electrode current collector 108 and the positive electrode current collector 107, respectively, and are not welded. There is no voltage drop due to. Thereby, the performance of the secondary battery 101 can be improved. Then, a predetermined amount of an electrolyte mainly composed of potassium hydroxide (KOH) is injected into the cell 109 to form the secondary battery 101.

(Structure of positive electrode 102 and negative electrode 103)
FIG. 12 is a perspective view of the positive electrode 102 (negative electrode 103). As shown in FIG. 12, the positive electrode 102 is coated with a resin R that is an insulating material. The positive electrode 102 includes a contact surface 102 a at one end that contacts the positive electrode current collector 107 and an opposite surface 102 b at the other end on the opposite side. Resin is coated on the opposite surface 102b. This resin R is formed by coating so as to cover burrs on the surface of the opposite surface 102b.

  On the other hand, in addition to the surface of the opposite surface 102b, the burr may be formed outward from the peripheral edge of the opposite surface 102b (in the radial direction of the electrode body 105). Since such a burr is directed to the adjacent negative electrode 103, when such a burr penetrates the separator 104, it comes into contact with the negative electrode 103 and a short circuit occurs. Therefore, before the resin is applied to the opposite surface 102b of the positive electrode 102, the end of the positive electrode 102 is sandwiched by pressing means, and such burrs are tilted inward of the opposite surface 102b. Thereafter, such a burr can be covered by applying a resin to the opposite surface 102 b, and a short circuit due to contact with the negative electrode 103 can be prevented.

  The resin application position is not limited to the opposite surface 102b, and may be applied to all surfaces other than the contact surface 102a at the outer peripheral end of the positive electrode 102. Further, since the structure of the negative electrode 103 is the same as that of the positive electrode 102, the description thereof is omitted.

(Modification of secondary battery 101)
The secondary battery 101 has been described with respect to a case where one electrode body 105 is accommodated in a cylindrical cell 109, but may be configured to accommodate a plurality of electrode bodies 105 as shown in FIG. The secondary battery 201 is a secondary battery in which a plurality of electrode bodies 105 are accommodated in a rectangular cell 202. The cell 202 includes a rectangular frame member 203, a negative electrode current collector 204, and a positive electrode current collector 205. The frame member 203 is made of an insulating material, and the negative electrode current collector 204 and the positive electrode current collector 205 are made of nickel. It consists of a plated steel plate.

  By arranging a plurality of electrode bodies 105 in parallel in the cell 202, a large-capacity secondary battery can be obtained.

  As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but various additions, modifications, or deletions can be made without departing from the spirit of the present invention. Moreover, you may change the shape of a negative electrode, a positive electrode, a separator, and a cell suitably. Therefore, such a thing is also included in the scope of the present invention.

1 Secondary battery (first embodiment)
2 Positive electrode 2a Contact surface (one end)
2b Opposite surface (the other end)
3 Negative electrode 3a Contact surface (one end)
3b Opposite surface (the other end)
4 Separator 5 Frame-shaped member 6 Positive electrode current collector 6a Positive electrode current collector surface 6b Positive electrode terminal surface 7 Negative electrode current collector 7a Negative electrode current collector surface 7b Negative electrode terminal surface 8 Cell 9 Electrode adsorption actuator 10 First press machine 11 First press part 12 Second press part 13 Second press machine 14 First press part 15 Second press part 16 Coating device 17 Storage tank 18 Nozzle 18a Coating part 18b First sensor part 18c Second sensor part 101 Secondary battery (second Embodiment)
102 Positive electrode 102a Contact surface (one end)
102b Opposite surface (the other end)
103 Negative electrode 103a Contact surface (one end)
103b Opposite surface (the other end)
104 Separator 105 Electrode body 106 Frame-shaped member 107 Positive electrode current collector 108 Negative electrode current collector 109 Cell 201 Secondary battery (modification)
202 Cell 203 Frame-shaped member 204 Negative electrode current collector 205 Positive electrode current collector B1, B2 Bali R resin

Claims (13)

An electrode body having a structure in which a sheet-like positive electrode and a sheet-like negative electrode are stacked via a separator is disposed between a positive electrode current collector and a negative electrode current collector arranged to face each other,
The electrode body is a state in which both electrodes are shifted in the facing direction of the current collector so that the positive electrode projects from one end of the current collector in the opposing direction and the negative electrode projects from the opposite one end. At least one electrode of the positive electrode and the negative electrode, wherein the positive electrode and the negative electrode are in contact with and electrically connected to the current collector at one end of the protruding side, respectively. The secondary battery which has an insulation part which distributes an insulating substance in the other end part on the opposite side to the side which protruded. In the insulating part,
The secondary battery according to claim 1, wherein a burr at the other end is included.   The secondary battery according to claim 2, wherein the burr at the other end does not protrude in the thickness direction of the positive electrode or the negative electrode. The insulating part is
The secondary battery according to any one of claims 1 to 3, wherein the secondary battery is formed along a longitudinal direction of the other end portion with a width equal to or smaller than a width dimension of the other end portion.   5. The electrode body has a plurality of the positive electrodes and the negative electrodes alternately stacked in a direction perpendicular to the facing direction of the current collector, with the clap-shaped separators interposed therebetween. The secondary battery as described in any one of.   The electrode body is formed by spirally winding the positive electrode and the negative electrode through a separator, and a winding axis is a direction orthogonal to a facing direction of the positive electrode current collector and the negative electrode current collector. Item 5. The secondary battery according to any one of Items 1 to 4.   The secondary battery according to claim 6, wherein a plurality of the electrode bodies are disposed between the current collectors. Sheet-like positive and negative electrodes,
Having one end in contact with the positive electrode current collector or the negative electrode current collector on the outer periphery, the other end on the opposite side, and an insulating part formed by applying an insulating material to the other end;
The electrode in which the insulating part and the burr at the other end do not protrude in the thickness direction of the electrode. It is a method for manufacturing a secondary battery comprising a sheet-like positive and negative electrode having one end contacting the positive electrode current collector or the negative electrode current collector on the outer periphery and the other end on the opposite side,
Pressing the electrode from both sides in its thickness direction, and pressing the burrs at the other end inward in the thickness direction of the electrode; and
And a coating step of coating an insulating material on the other end. In the pressing step,
The method for manufacturing a secondary battery according to claim 9, wherein the electrode is heated. In the pressing step,
The method for manufacturing a secondary battery according to claim 9 or 10, wherein the temperature of the electrode is heated to 30C to 90C. In the coating step,
The manufacturing method of the secondary battery as described in any one of Claims 9-11 provided with the means to detect the starting point and the end point of the said electrode. It is a secondary battery manufacturing apparatus having a sheet-like positive and negative electrode having one end contacting the positive electrode current collector or the negative electrode current collector on the outer periphery and the other end on the opposite side,
A pressing means for pressing the electrode from both sides in the thickness direction and simultaneously heating the electrode to tilt the burr at the other end inward in the thickness direction of the electrode;
An apparatus for manufacturing a secondary battery, comprising: a sensor that detects a start point and an end point of an electrode; and an applying unit that applies an insulating material to the other end.

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