JP2013045644A - Secondary battery and electrode sheet for secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery in which satisfied connections between a positive electrode plate and a positive electrode collector, and between a negative electrode plate and a negative electrode collector can be achieved and a state of the satisfied connections can be maintained.SOLUTION: The secondary battery includes: a positive electrode collector and a negative electrode collector arranged to face with each other; and a positive electrode plate and a negative electrode plate arranged between the positive electrode collector and the negative electrode collector, and alternately stacked via a separator in the direction orthogonal to the facing direction of both collectors. The positive electrode plate has a positive electrode contact surface in contact with the positive electrode collector at an outer peripheral end thereof, and the negative electrode plate has a negative electrode contact surface in contact with the negative electrode collector at an outer peripheral end thereof. An electrode sheet is interposed at least one of between the positive electrode collector and the positive electrode contact surface and between the negative electrode collector and the negative electrode contact surface, the electrode sheet using a foam metal having a gap as a base material and obtained by adding an elastic resin into the foam metal.

Description

  The present invention relates to a secondary battery and an electrode sheet for the secondary battery.

  Conventionally, secondary batteries are used in various products such as mobile phones, mobile PCs, electric tools, and electric bicycles. In recent years, secondary batteries are also used for power generation using natural energy such as wind power generation and solar power generation. This is used to supplement unstable output with a secondary battery and smooth the output, and a large-capacity secondary battery is used. In addition, it is known that large-capacity secondary batteries are mounted on vehicles such as hybrid cars, electric cars, and trains.

  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.

  As a conventional nickel-metal hydride secondary battery, a wound battery or a square battery is mainstream. A wound battery comprises an electrode body formed by winding a positive electrode plate and a negative electrode plate through a separator, and the electrode body is accommodated in a battery container together with an electrolyte. In addition, the rectangular battery includes an electrode body that is formed by alternately laminating a plurality of positive and negative electrode plates with separators interposed therebetween, and the electrode body is housed in a battery container together with an electrolytic solution. In any battery, the positive electrode plate and the negative electrode plate are connected to the positive electrode current collector and the negative electrode current collector, respectively, and electricity is taken out.

  In a rectangular battery, a plurality of positive plates are in contact with and electrically connected to a positive current collector, and a plurality of negative plates are in contact with and electrically connected to a negative current collector via a bellows-shaped separator. Yes. At this time, a shift occurs between the positive electrode plate and the positive electrode current collector, and if the contact between them becomes insufficient, the contact resistance increases, leading to a decrease in battery capacity and a decrease in battery performance. In order to avoid this, it is necessary to maintain a state where the positive electrode plate and the positive electrode current collector, and the negative electrode plate and the negative electrode current collector are in firm contact with each other.

  In invention of patent document 1, the method of welding the end surface of each laminated | stacked electrode plate directly to a collector with the electron beam welding method is disclosed. That is, this is a method in which each electrode plate is brought into contact with each other in a posture standing upright with respect to the surface of the current collector, and at this time, the current collector and the electrode plate constitute a T-shaped joint. (See FIG. 1 (d) and FIG. 2 (b) of Patent Document 1).

  In the invention of Patent Document 2, a bellows-like separator is alternately arranged between the positive electrode current collector and the negative electrode current collector so as to be close to both current collectors, and is partitioned by the bellows-shaped separator and the positive electrode current collector. The positive electrode active material is filled in the space, the space defined by the bellows-shaped separator and the negative electrode current collector is filled with the negative electrode active material, and the positive electrode active material and the negative electrode active material are alternately incorporated with the separator interposed therebetween. In a battery constructed by filling a battery cell with an electrolyte solution, a pressure in which a 2 mm wide pressure absorbing member having a sealed space containing a rubber ball and air is inserted between an active material and a current collector An absorbent member is disclosed (see FIG. 6 of Patent Document 2). Further, an invention is disclosed in which the pressure absorbing member has a honeycomb structure (see FIG. 4 of Patent Document 2).

Japanese Patent No. 2616197 JP 2003-317795 A

  However, in the invention of Patent Document 1, the electric resistance of the welded portion is large, and a loss occurs when taking out electricity.

  On the other hand, in the invention of Patent Document 2, since the pressure absorbing member has a honeycomb structure or rubber balls are arranged inside, manufacturing is difficult and costly. In addition, since such a pressure absorbing member has a complicated structure, it needs to be molded with a certain width (for example, 2 mm or more), and there is a limit to reducing the thickness.

  In order to solve these problems, the object of the present invention is to maintain a state where the positive electrode plate and the positive electrode current collector, and the negative electrode plate and the negative electrode current collector are securely and reliably electrically connected, The purpose is to suppress a decrease in performance. Another object of the present invention is to provide an electrode sheet that is easy to manufacture without using welding for connecting the electrode plate and the current collector, and a secondary battery using the electrode sheet.

In order to achieve the above object, a secondary battery according to the present invention includes a positive electrode current collector and a negative electrode current collector that are disposed to face each other, and between the positive electrode current collector and the negative electrode current collector. A positive electrode plate and a negative electrode plate that are alternately stacked in a direction orthogonal to the opposing direction of both current collectors via separators,
The positive electrode plate has a positive electrode contact surface in contact with the positive electrode current collector at an outer peripheral end portion, and the negative electrode plate has a negative electrode contact surface in contact with the negative electrode current collector at an outer peripheral end portion;
At least one of the positive electrode current collector and the positive electrode contact surface and between the negative electrode current collector and the negative electrode contact surface is a foam metal having a void portion as a base material. It is characterized by interposing an electrode sheet formed by adding an elastic resin (CL1).

  According to this configuration, since the electrode sheet is formed by adding the elastic resin to the void portion of the foam metal that is inelastic, the electrode sheet can be made elastic. By arranging this between the electrode plate (positive electrode plate or negative electrode plate) and the current collector (positive electrode current collector or negative electrode current collector), the electrode plate bites into the electrode sheet, and the electrode sheet becomes the electrode plate. Since the electrode plate is biased to the side, the electrode plate and the current collector can be securely and reliably connected via the electrode sheet.

  In addition, the use of the secondary battery can suppress the displacement of the electrode plate, which can occur due to the weakening of the assembly power (compression force) of the secondary battery, and the electrode plate and the current collector Can maintain a good connection state. That is, the performance degradation of the secondary battery can be suppressed.

  In addition, an electrode sheet may be provided in any one of a positive electrode plate and a positive electrode collector, and a negative electrode plate and a negative electrode collector, and may be provided in both.

  Here, adding an elastic resin to the inside of the foamed metal means, for example, adding an elastic resin by cutting out the inside of the base material, or elasticity to a void inside the base material as in the invention of claim 2 below. It is conceivable to add resin.

  The secondary battery according to the present invention is characterized in that the electrode sheet is formed by impregnating the gap portion with an elastic resin (CL2).

  According to this configuration, the elastic resin can be easily formed by simply impregnating the elastic resin with the base material, which is a foam metal, to the void portion. Moreover, a thin electrode sheet can be easily formed by using a thin substrate.

  The secondary battery according to the present invention is characterized in that the base material is formed by subjecting foamed urethane having a porosity of 50% or more to nickel plating (CL3).

  According to this configuration, since the porosity of the substrate is 50% or more, the electrode sheet can have sufficient elasticity by adding an elastic resin to the void. In order for the electrode sheet to have sufficient elasticity and strength, the porosity of the substrate is preferably 70 to 99%, more preferably around 95%.

  In the secondary battery according to the present invention, an elastic member may be sandwiched between the base materials (CL4).

  According to this configuration, an elastic electrode sheet can be obtained even when an elastic member is sandwiched between substrates. Further, an elastic member may be further sandwiched between the base material impregnated with the elastic resin. Here, “sandwiching the elastic member between the base materials” means, for example, a mode in which the base material is cut approximately in half in the thickness direction and the elastic members are sandwiched therebetween, or a space is provided inside the base material. A form in which an elastic member is sandwiched there is conceivable.

  In the secondary battery according to the present invention, the elastic resin may be an ethylene / vinyl acetate copolymer resin or an olefin resin (CL5).

  Here, the ethylene / vinyl acetate copolymer resin refers to a resin such as EVA, and the olefin resin refers to a resin such as PP or PE.

  In the secondary battery according to the present invention, the elastic resin is a resin mixed with conductive carbon (CL6).

  According to this structure, since the space | gap part of a base material is filled with the elastic resin containing electroconductive carbon, the electroconductivity of an electrode sheet can be improved.

A secondary battery according to the present invention includes a rectangular cell that houses an electrode body including the positive electrode plate, the negative electrode plate, and the separator together with an electrolyte solution,
The cell includes a frame-shaped member surrounding a side end portion of the electrode body, the positive electrode current collector and the negative electrode current collector that cover and cover an opening of the frame-shaped member,
The positive electrode current collector functions as a positive electrode terminal surface on the surface exposed to the outside of the battery, and a positive current collector surface on the surface facing the inside of the battery, and the negative electrode current collector has a surface exposed on the outside of the battery. As a negative electrode terminal surface, a surface facing the inside of the battery functions as a negative electrode current collecting surface (CL7).

  According to this configuration, the positive electrode current collector and the negative electrode current collector that are arranged opposite to each other constitute a part of the cell, so that both current collectors have a structure that facilitates assembly of the battery module. And a frame-shaped member made of an insulating material are joined in a liquid-tight manner, so that a sufficient hermeticity can be secured by the battery alone. Further, in the battery module using this battery, the structure can be simplified by omitting the sealing ensuring member and the external short-circuit preventing member, and the weight and volume can be greatly reduced.

  The secondary battery according to the present invention is characterized in that the positive electrode current collector and the negative electrode current collector are pressed in the opposite direction so that the positive electrode plate and the negative electrode plate are bitten into the electrode sheet (CL8).

  According to this configuration, a predetermined pressing force can be maintained even after aging due to the use of the secondary battery, and the positive electrode plate, the negative electrode plate and the positive electrode current collector, the contact state between the negative electrode current collector, The increase in the contact resistance can be suppressed and the performance of the secondary battery can be maintained. The predetermined pressing force refers to a pressing force that can maintain the contact state between the positive electrode plate, the negative electrode plate, the positive electrode current collector, and the negative electrode current collector.

An electrode sheet according to the present invention is disposed between a positive electrode current collector and a negative electrode current collector, which are arranged to face each other, and between the positive electrode current collector and the negative electrode current collector, and facing both current collectors A positive electrode plate and a negative electrode plate that are alternately stacked via separators in a direction perpendicular to the direction, the positive electrode plate has a positive electrode contact surface that contacts the positive electrode current collector at an outer peripheral end; In the secondary battery, the negative electrode plate has a negative electrode contact surface that contacts the negative electrode current collector at an outer peripheral end.
Using the foam metal having a gap as a base material, the foam is interposed between at least one of the positive electrode current collector and the positive electrode contact surface and between the negative electrode current collector and the negative electrode contact surface. An elastic resin is added to the inside of the metal (CL9).

  According to this configuration, since the elastic resin is added to the void portion of the foam metal that is inelastic, an electrode sheet having elasticity can be obtained. By arranging this between the electrode plate (positive electrode plate or negative electrode plate) and the current collector (positive electrode current collector or negative electrode current collector), the electrode plate bites into the electrode sheet, and the electrode sheet becomes the electrode plate. Since the electrode plate is biased to the side, the electrode plate and the current collector can be securely and reliably connected via the electrode sheet.

  In addition, the use of the secondary battery can suppress the displacement of the electrode plate, which can occur due to the weakening of the assembly power (compression force) of the secondary battery, and the electrode plate and the current collector Can maintain a good connection state. That is, by using this electrode sheet, it is possible to suppress the performance deterioration of the secondary battery.

  In the electrode sheet according to the present invention, the base material is preferably formed by subjecting foamed urethane having a porosity of 50% or more to nickel plating and impregnating the void portion with an elastic resin (CL10).

  According to this configuration, since the porosity of the substrate is 50% or more, the electrode sheet can have sufficient elasticity by adding an elastic resin to the void. Further, since the elastic resin can be added to the gap simply by impregnating the base material, which is a foam metal, into the elastic resin, an elastic electrode sheet can be easily formed. Moreover, a thin electrode sheet can be easily formed by using a thin substrate.

  In the electrode sheet of the present invention, an elastic member may be sandwiched between the substrates (CL11).

  As described above, the present invention maintains the electrical connection between the electrode plate and the current collector in a good state by interposing the elastic electrode sheet between the electrode plate and the current collector. . That is, an increase in contact resistance due to a displacement of the electrode plate due to use is suppressed, and a decrease in battery performance is suppressed.

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 the elements on larger scale of the electrode body in the secondary battery of FIG. It is sectional drawing of the secondary battery of FIG. It is the elements on larger scale of FIG. FIG. 2 is a partially cutaway side view of a battery module in which a plurality of the secondary batteries of FIG. 1 are stacked. It is a partially broken perspective view which shows the winding type electrode body in the secondary battery which concerns on 2nd Embodiment of this invention. It is a top view in the electrode body of FIG. FIG. 8 is a partially broken perspective view of a secondary battery loaded with a plurality of electrode bodies of FIG. 7. FIG. 10 is a cross-sectional view of the secondary battery of FIG. 9.

  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 7 and a rectangular positive electrode which is disposed so as to face the X-direction so as to cover the frame-shaped member 7 and whose peripheral portion is bent at a substantially right angle. The current collector 8 and the negative electrode current collector 9 constitute a square cell 10. Inside the cell 10, an electrode body 2 including a positive electrode plate 3 made of the positive electrode active material, a negative electrode plate 4 made of the negative electrode active material, and a separator 5 bent in a bellows shape is provided as an electrolyte solution. It is stored with. The separator 5 is a hydrophilic separator made of a polypropylene nonwoven fabric.

  As shown in the partially enlarged view of FIG. 3, the electrode body 2 is arranged in a state where the positive electrode plate 3 and the negative electrode plate 4 are alternately sandwiched between the separators 5 bent in a bellows shape. . In the present embodiment, the positive electrode plate 3 and the negative electrode plate 4 are formed in a strip shape having a length of 230 mm, a width of 29 mm, and a width of 0.35 mm.

  As shown in the cross-sectional view of FIG. 4, the positive electrode plate 3 and the negative electrode plate 4 are stacked in the Y direction with a separator 5 interposed therebetween. An electrode sheet 6 is interposed between the positive electrode plate 3 and the positive electrode current collector 8 and between the negative electrode plate 4 and the negative electrode current collector 9. Moreover, it arrange | positions so that the edge part (upper end in FIG. 4) of the positive electrode plate 3 may bite into the upper electrode sheet 6, and it arrange | positions so that the edge part (lower end in FIG. 4) of the negative electrode plate 4 may bite into the lower electrode sheet 6. (See FIG. 5). Moreover, the end surfaces of the positive electrode plate 3 and the negative electrode plate 4 are in contact with the electrode sheet 6, and the positive electrode plate 3 and the positive electrode current collector 8, and the negative electrode plate 4 and the negative electrode current collector 9 are electrically connected via the electrode sheet 6. Connected.

  In the secondary battery 1 of the present embodiment, the conduction between the positive electrode plate 3, the negative electrode plate 4, the electrode sheet 6, the positive electrode current collector 8, and the negative electrode current collector 9 is mixed with foreign matters such as metal scraps. In order to prevent this and to simplify the process, welding is not performed and the current collectors 8 and 9 are secured by contact pressure (pressing) in the facing direction X.

  As described above, the elastic electrode sheet 6 is interposed between the positive electrode plate 3 and the negative electrode plate 4, and the positive electrode current collector 8 and the negative electrode current collector 9, so that the upper electrode sheet 6 faces the positive electrode plate 3 side. Since the lower electrode sheet 6 is biased toward the negative electrode plate 4, a good contact state between the positive electrode plate 3 and the negative electrode plate 4 and the electrode sheet 6 can be maintained. Specifically, even if the assembly force (pressing force) decreases due to the use of the secondary battery 1 over time, the displacement of the positive electrode plate 3 or the negative electrode plate 4 is prevented, and the battery performance decreases due to an increase in contact resistance. Can be suppressed. That is, in the secondary battery 1 of the present embodiment, it is possible to maintain an electrically good contact state between the positive electrode plate 3 and the negative electrode plate 4, and the positive electrode current collector 8 and the negative electrode current collector 9. .

  The positive electrode current collector 8 and the negative electrode current collector 9 are formed of nickel-plated steel plates, and the battery inner surface of the positive electrode current collector 8 functions as the positive electrode current collector surface 8a. The exposed surface functions as the positive electrode terminal surface 8b. Similarly, the battery inner surface of the negative electrode current collector 9 functions as the negative electrode current collector surface 9a, and the exposed surface outside the battery functions as the negative electrode terminal surface 9b.

(Structure of electrode sheet 6)
Next, the structure of the electrode sheet 6 will be described. The electrode sheet 6 is formed by forming foamed nickel obtained by applying nickel plating to foamed urethane in a sheet shape. As shown in FIG. 5, the electrode sheet 6 includes a base material 6 a made of nickel foam and an internal space 6 b. The gap 6b is impregnated with an elastic resin R made of EVA (ethylene / vinyl acetate copolymer resin). Thus, the elastic electrode sheet 6 can be formed by impregnating the foamed nickel, which is an inelastic material, with the elastic resin R. In addition, the porosity of the base material 6a in this embodiment is around 95%.

  Further, the entire gap 6b may be impregnated with the elastic resin R, or the gap 6b may be impregnated with the elastic resin R as shown in FIG.

  Moreover, since the electrode sheet 6 can be produced simply by impregnating the foamed metal with the elastic resin R, the production is easy. Therefore, the electrode sheet 6 can be easily reduced in thickness. That is, a thin foam metal may be prepared and impregnated with the elastic resin R.

  In addition to EVA, the elastic resin R can also use olefins such as PP and PE.

  Further, in order to increase the conductivity of the electrode sheet 6, oxidation-resistant carbon may be mixed into the elastic resin R. Thereby, the electrical conduction from the negative electrode plate 4 to the negative electrode current collector 9 is improved. That is, when the elastic resin R is non-conductive, a part of the electricity bypasses the edge of the electrode sheet 6 from the negative electrode plate 4 and reaches the negative electrode current collector 9, and the elastic resin R becomes conductive. If so, the negative electrode current collector 9 can be reached from the negative electrode plate 4 through the inside of the electrode sheet 6 as it is.

  In addition to forming the electrode sheet 6 by impregnating the elastic resin R in the gap 6b of the base material 6a, the electrode sheet 6 is once cut in about 1/2 in the thickness direction, It can also be formed so as to sandwich an elastic member made of an elastic resin having conductivity. Furthermore, you may impregnate the elastic part in the space | gap part of the electrode sheet formed in this way.

(Battery module M)
Next, a battery module M in which a plurality of secondary batteries 1 (30 in this embodiment) are stacked will be described. As shown in FIG. 6, the battery module M includes 30 secondary batteries 1, a side plate 11 and a compression plate 12 surrounding the secondary battery 1, and these are covered with a casing 13 made of an insulating material. Further, the side plate 11, the compression plate 12, and the casing 13 are fastened by bolts or screws, and the 30 secondary batteries 1 are held in a state of being pressed in the stacking direction (Z direction).

  As described above, in the secondary battery 1, the surface of the positive electrode current collector 8 exposed outside the battery functions as the positive electrode terminal surface 8 b and the surface of the negative electrode current collector 9 exposed outside the battery functions as the negative electrode terminal surface 9 b. Therefore, these secondary batteries are electrically connected by abutting and laminating the positive electrode terminal surface 8b and the negative electrode terminal surface 9b of adjacent secondary batteries. Further, a conductive heat dissipation plate 14 for cooling the secondary battery 1 may be interposed between the adjacent secondary batteries 1.

(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 which the electrode sheet 6 is applied to a wound battery. The main difference from the first embodiment is the structure of the electrode plate and the separator.

(Structure of secondary battery 101)
FIG. 7 is a partially broken perspective view showing the structure of the wound electrode body 102 in the secondary battery 101 of the present invention, and FIG. 8 is a plan view of the electrode body 102. As shown in FIGS. 7 and 8, the substantially cylindrical electrode body 102 transmits a sheet-like negative electrode plate 103, a sheet-like positive electrode plate 104, and ions that are interposed between the two electrode plates but transmits electrons. And a plate-like separator 105 that is not allowed to move. The negative electrode plate 103 and the positive electrode plate 104 are wound in a spiral shape in a state where they are overlapped while being shifted up and down via the separator 105 to constitute the electrode body 102. That is, in the axial direction of the electrode body 102, the upper end of the negative electrode plate 103 protrudes above the separator 105, and the lower end of the positive electrode plate 104 protrudes below the separator 105 (see FIG. 7). Further, in the direction orthogonal to the axial direction of the electrode body 102, the negative electrode plates 103 and the positive electrode plates 104 are alternately stacked via the separator 105 from the outer side of the electrode body 102 to the inner side in the radial direction. (See FIG. 8).

  As shown in FIG. 9, the secondary battery 101 is a secondary battery in which a plurality of electrode bodies 102 are accommodated in parallel in a rectangular cell 110. The cell 110 includes a rectangular frame-shaped member 107, a rectangular negative electrode current collector 108 and a positive electrode current collector that are arranged to face the P-shape so as to cover the frame-shaped member 107 and have a peripheral edge bent at a substantially right angle. 109. The frame-shaped member 107 is made of an insulating material, and the negative electrode current collector 108 and the positive electrode current collector 109 are made of a steel plate plated with nickel.

  As shown in FIG. 10, the electrode sheets 106 are arranged above and below the electrode body 102 so as to be interposed between the electrode body 102 and the negative electrode current collector 108 or the positive electrode current collector 109. Then, the upper end portion of the negative electrode plate 103 is arranged so as to bite into the upper electrode sheet 6, and the negative electrode plate 103 and the negative electrode current collector 108 are electrically connected. Similarly, the lower end portion of the positive electrode plate 104 is arranged so as to bite into the lower electrode sheet 106, and the positive electrode plate 104 and the positive electrode current collector 109 are electrically connected. The inner surface of the negative electrode current collector 108 functions as the negative electrode current collecting surface 108a, and the surface exposed to the outer side of the battery functions as the negative electrode terminal surface 108b. The surface inside the battery of the positive electrode current collector 109 functions as the positive electrode current collecting surface 109a, and the surface exposed to the outside of the battery functions as the positive electrode terminal surface 109b.

  Further, the negative electrode plate 103 and the positive electrode plate 104 protruding above and below the electrode body 102 are only brought into contact with the electrode sheet 106 when electrically connected to the negative electrode current collector 108 and the positive electrode current collector 109. Since it is not welded, there is no voltage drop due to the electrical resistance of the weld. 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 charged into the cell 110 to form the secondary battery 101.

  In the secondary battery 101 configured in this manner, the upper electrode sheet 106 is biased toward the negative electrode plate 103 and the lower electrode sheet 106 is biased toward the positive electrode plate 104 due to the presence of the elastic electrode sheet 106. Therefore, it is difficult for these contact surfaces to be displaced, so that an increase in contact resistance can be suppressed, and a decrease in battery performance can be suppressed.

  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 plate, a positive electrode plate, a separator, and a cell suitably. Therefore, such a thing is also included in the scope of the present invention.

  The secondary battery according to the present invention can be suitably used as a secondary battery for electric railway vehicles, heavy machinery, microgrids, and wind power generation.

1 Secondary battery (first embodiment)
2 Electrode body 3 Positive electrode plate 3a Positive electrode contact surface 4 Negative electrode plate 4a Negative electrode contact surface 5 Separator 6 Electrode sheet 6a Base material 6b Space 7 Frame-shaped member 8 Positive electrode current collector 8a Positive electrode current collector surface 8b Positive electrode terminal surface 9 Negative electrode Current collector 9a Negative electrode current collector surface 9b Negative electrode terminal surface 10 Cell 11 Side plate 12 Compression plate 13 Casing 14 Heat sink 101 Secondary battery (second embodiment)
102 Electrode 103 Negative electrode plate 103a Negative electrode contact surface 104 Positive electrode plate 104a Positive electrode contact surface 105 Separator 106 Electrode sheet 107 Frame member 108 Negative electrode current collector 108a Negative electrode current collector surface 108b Negative electrode terminal surface 109 Positive electrode current collector 109a Positive electrode current collector Electrical surface 109b Positive terminal surface 110 Cell R Elastic resin

Claims (11)

A positive electrode current collector and a negative electrode current collector disposed to face each other;
A positive electrode plate and a negative electrode plate, which are arranged between the positive electrode current collector and the negative electrode current collector and are alternately stacked via separators in a direction perpendicular to the opposing direction of the both current collectors;
The positive electrode plate has a positive electrode contact surface in contact with the positive electrode current collector at an outer peripheral end portion;
The negative electrode plate has a negative electrode contact surface in contact with the negative electrode current collector at an outer peripheral end,
At least one of the positive electrode current collector and the positive electrode contact surface and between the negative electrode current collector and the negative electrode contact surface is a foam metal having a void portion as a base material. A secondary battery in which an electrode sheet made of elastic resin is interposed. The electrode sheet is
The secondary battery according to claim 1, wherein the void is impregnated with an elastic resin. The substrate is
The secondary battery according to claim 1, which is formed by applying nickel plating to urethane foam having a porosity of 50% or more. The electrode sheet according to claim 1, wherein an elastic member is sandwiched between the base materials. The elastic resin is
The secondary battery according to claim 1, which is an ethylene / vinyl acetate copolymer resin or an olefin resin. The elastic resin is
The secondary battery according to claim 1, which is a resin mixed with conductive carbon. An electrode body composed of the positive electrode plate, the negative electrode plate, and the separator is provided with a rectangular cell that accommodates an electrolyte solution,
The cell is
A frame-shaped member surrounding a side end of the electrode body;
The positive electrode current collector and the negative electrode current collector that cover and cover the opening of the frame-shaped member,
The positive electrode current collector, the surface exposed to the outside of the battery as a positive electrode terminal surface, the surface facing the inside of the battery functions as a positive electrode current collector surface,
The secondary battery according to claim 1, wherein the negative electrode current collector functions as a negative electrode terminal surface at a surface exposed to the outside of the battery and a negative electrode current collector surface at a surface facing the inside of the battery. Pressing the positive electrode current collector and the negative electrode current collector in opposite directions;
The secondary battery according to claim 1, wherein the positive electrode plate and the negative electrode plate are arranged so as to bite into the electrode sheet. A positive electrode current collector and a negative electrode current collector disposed to face each other;
A positive electrode plate and a negative electrode plate, which are arranged between the positive electrode current collector and the negative electrode current collector and are alternately stacked via separators in a direction perpendicular to the opposing direction of the both current collectors;
The positive electrode plate has a positive electrode contact surface in contact with the positive electrode current collector at an outer peripheral end portion, and the negative electrode plate has a negative electrode contact surface in contact with the negative electrode current collector at an outer peripheral end portion. In batteries,
Using the foam metal having a gap as a base material, the foam is interposed between at least one of the positive electrode current collector and the positive electrode contact surface and between the negative electrode current collector and the negative electrode contact surface. An electrode sheet obtained by adding an elastic resin to the inside of a metal. The substrate is
It is formed by applying nickel plating to urethane foam with a porosity of 50% or more,
The electrode sheet according to claim 9, wherein the gap is impregnated with an elastic resin. The electrode sheet according to claim 9 or 10, wherein an elastic member is sandwiched between the base materials.

Images