JP2012028023A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery that is electromagnetically shielded without increasing the weight of the whole battery.SOLUTION: A battery (1) having a battery element (2) coated with a resin-metal composite film (6), as a jacket material, formed by sticking a resin film (8) and a metal film (7) together in layers such that margin parts (6a) protrude from an outer periphery of the battery element (2), and storing and sealing the battery element (2) inside the jacket material by joining the upper and lower margin parts (6a), protruding from the outer periphery, together by heat sealing is characterized in that a conductive member (21) penetrates the part (10) joined by the heat sealing, and is grounded.

Description

  The present invention relates to a battery, and more particularly to a laminated battery pack.

  In a vehicle power supply device having a battery pack 10 connected to an electric circuit that performs a switching operation, a device using a floor panel 14 as a noise shield member is described (see Patent Document 1).

JP 2001-294048 A

  However, the technique disclosed in Patent Document 1 merely replaces a part of a metal casing having a noise shielding function with a floor panel. That is, the metal casing for performing electromagnetic shielding outside the battery main body is still necessary, and the entire battery including the metal casing is increased in weight and size.

  Therefore, an object of the present invention is to provide a battery that can be electromagnetically shielded without increasing the weight of the entire battery.

  In the present invention, a resin-metal composite film formed by laminating a resin film and a metal film is used as an exterior material, and the battery element is covered with the resin-metal composite film so that a margin part protrudes from the outer periphery of the battery element. In addition, on the premise of a battery in which the upper and lower margins protruding from the outer periphery are joined by thermal fusion and the battery element is housed inside the exterior material and sealed, it is joined by the thermal fusion. The conductive member is passed through the portion and the conductive member is connected to the ground.

  According to the present invention, since the metal film as the exterior material has a function of electromagnetic shielding, it is not necessary to form a ground by the metal casing. Thereby, a lightweight and compact battery can be formed.

It is a schematic longitudinal cross-sectional view of the assembled battery seen in the site | part from which the high electric power tab of 1st Embodiment of this invention was taken out. It is a schematic longitudinal cross-sectional view of the assembled battery seen in the site | part where the high voltage tab of 1st Embodiment of this invention is not taken out. It is a schematic plan view of the assembled battery of 1st Embodiment. It is an electrical wiring diagram which uses an assembled battery as a power supply of a motor. It is a schematic plan view of the assembled battery of 2nd Embodiment. It is a schematic plan view of the assembled battery of 3rd Embodiment. It is a schematic longitudinal cross-sectional view of the assembled battery seen in the site | part where the high electric power tab of 4th Embodiment is not taken out. It is a schematic longitudinal cross-sectional view of the assembled battery seen in the site | part where the high electric power tab of 5th Embodiment is not taken out. It is detail drawing of the retaining part of 5th Embodiment. It is a schematic longitudinal cross-sectional view of the assembled battery seen in the site | part where the high electric power tab of 6th Embodiment is not taken out. It is detail drawing of the electrically-conductive member of 6th Embodiment. It is a schematic longitudinal cross-sectional view of the assembled battery of 7th Embodiment. It is the schematic which shows the connection method of the electrically-conductive member of 7th Embodiment, and an earth wire. It is a schematic longitudinal cross-sectional view of the assembled battery of 8th Embodiment. It is a schematic longitudinal cross-sectional view of the assembled battery of 8th Embodiment. It is a schematic perspective view of 9th Embodiment which expands and shows a part of assembled battery. It is the top view, back view, and sectional drawing of the bipolar electrode of an Example. It is the top view and sectional drawing of the bipolar electrode of the Example for demonstrating the state by which the seal | sticker part precursor was apply | coated. It is the top view and sectional drawing of the bipolar electrode of the Example for demonstrating the state covered with the separator. It is a longitudinal cross-sectional view of the battery element of an Example. It is a longitudinal cross-sectional view of the assembled battery of an Example. It is a top view of the assembled battery of an Example.

  Embodiments will be described below with reference to the drawings. In the following drawings, in order to facilitate understanding of the invention, the thickness and shape of each layer such as elements constituting the stacked battery are exaggerated. It is not necessarily a scale according to the actual size. The stacked battery is a battery configured by stacking at least two unit cells, but is also a battery in which at least two unit cells are combined, that is, an assembled battery.

(First embodiment)
1A and 1B are schematic longitudinal sectional views of the assembled battery 1 according to the first embodiment of the present invention, and FIG. 2 is a schematic plan view of the assembled battery 1 according to the first embodiment. In FIG. 1A and FIG. 1B, it is described as if there is a gap between the members, but this is for ease of viewing, and the reason why gaps are actually provided between the members is not shown. Not. As shown in FIG. 2, there are a portion where the high-power tabs 4, 5 are taken out and a portion where the high-power tabs 4, 5 are not taken out around the assembled battery. FIG. 1A is a schematic cross-sectional view of a portion where the high-power tabs 4 and 5 are taken out, and FIG. 1B is a schematic cross-sectional view of a portion where the high-power tabs 4 and 5 are not taken out.

  In FIG. 1A and FIG. 1B, the battery element 2 as one lump is comprised by laminating | stacking three bipolar type secondary battery elements 3 formed in the rectangle and flat form as a whole in the up-down direction. As shown in FIG. 1A, a pair of high-power tabs 4 and 5 are connected to the uppermost and lowermost stages of the battery element 2, and one high-power tab 4 is taken out on the right side and the other high-power tab 5 is taken out on the left side. ing.

  FIG. 2 does not correspond exactly to FIG. 1A. That is, in FIG. 1A, the pair of high-power tabs 4 and 5 are taken out from the left and right, but in FIG. 2, the high-power tabs 4 and 5 are both taken out from the left side.

  The assembled battery 1 shown in FIG. 1A is a simplified illustration of the assembled battery 1 shown in FIG. 19 described later. Actually, the assembled battery 1 shown in FIG. 1A is obtained by stacking eight bipolar secondary battery elements 45 in the vertical direction as shown in FIG. FIG. 1A shows a stack of three bipolar secondary battery element 45 for simplification. The bipolar secondary battery element 3 shown in FIG. 1A is the same as the bipolar secondary battery element 45 shown in FIG.

  One bipolar secondary battery element 45 shown in FIG. 19 is obtained by stacking 12 unit cells 41 in the vertical direction (connected in series) as will be described later with reference to FIG. For simplicity, FIG. 18 shows a bipolar secondary battery element 45 in which four unit cells 41 are connected in series by stacking five bipolar electrodes in the vertical direction. One unit cell 41 is composed of three elements: an element between two adjacent current collectors 32, 32, that is, a negative electrode 34, a separator 36 soaked with gel electrolyte, and a positive electrode 33. Yes.

  Returning to FIG. 1A and FIG. 1B, the entire pair of high voltage tabs 4 and 5 and the battery element 2 are covered with a battery exterior material from above and below. Here, as an exterior material, a resin-metal composite laminate film 6 obtained by bonding a film 7 of a metal (including an alloy) such as aluminum, stainless steel, nickel, or copper and a film 8 of a resin (insulator) such as a polypropylene film. Is used. The resin-metal composite laminate film 6 covers the entire battery element 2 and the pair of high voltage tabs 4 and 5 from above, with the margin 6a protruding almost uniformly on the outer periphery of the battery element 2, and also on the lower side. The margin allowance 6a having the same width as the upper resin-metal laminate film 6 is coated on the outer periphery of the battery element 2 almost evenly, and the upper and lower margin allowances 6a protruding on the outer periphery are joined by thermal fusion. Thus, the pair of high voltage tabs 4 and 5 and the battery element 2 are housed inside the exterior material and sealed. Thus, the part joined by thermal fusion is hereinafter referred to as “thermal fusion part” 10. The heat-sealed part 10 is indicated by a one-dot chain line circle.

  The metal film 7 in addition to the resin film 8 covers the entire battery element 2 and the pair of high voltage tabs 4 and 5 because water (moisture) penetrates into the interior of the exterior material, which impedes battery performance. It is for doing so. For this reason, when heat-sealing the upper and lower margin allowances 6a, it is preferable to vent the air inside the exterior material. The reason for removing air is that air contains moisture. The pair of high voltage tabs 4, 5 are sandwiched between outer packaging materials at the heat fusion part 10 and are exposed to the outside of the resin-metal composite laminate film 6.

  Now, the assembled battery 1 is used as a power source of a motor 11 (used in an electric vehicle or a hybrid vehicle) as shown in FIG. 3, for example. In this case, since the DC output from the assembled battery 1 is converted into alternating current or the current from the assembled battery 1 is controlled by an external device such as an electric circuit that performs a switching operation like the inverter 12, the inverter 12, the inverter Electromagnetic waves are dissipated from a control device (not shown) for controlling 12, the assembled battery 1, the high-voltage wirings 13 and 14 connecting the inverter 12 and the assembled battery 1, and the like. In order to prevent the radiation of the electromagnetic wave, it is necessary to perform electromagnetic shielding on each part. In addition, although the inverter 12 was mentioned as an external device, it cannot be overemphasized that the application of this invention has the application to the external device which switches other than an inverter.

  For example, the high-power wirings connecting the inverter 12 and the assembled battery 1 are the high-power wirings 13 and 14 with electromagnetic shield in order to prevent the radiation of electromagnetic waves. There are various types of high-voltage wiring with electromagnetic shielding, and any type can be used. Here, it is assumed that the lead wire 15 at the center is covered with an insulating material 16 and further covered with the insulating material 16 and a wire mesh layer 17 knitted with a metal having a small electric resistance such as copper or aluminum. In such high-power wirings 13 and 14 with electromagnetic shield, the ground wire 18 is connected to the outermost wire mesh layer 17 to be grounded.

  In the present invention, a case where electromagnetic shielding is performed on the assembled battery 1 is particularly handled. The assembled battery 1 is very simple and lightweight and compact by using the resin-metal composite laminate film 6 as an exterior material. Although the electromagnetic shield structure is formed, if the electromagnetic shielding is performed by further arranging the metal casing around the entire periphery of the assembled battery 1, the overall weight including the assembled battery 1 increases as a result. End up.

  In addition, when the earth for the electromagnetic shield is fixed to a metal casing, connection reliability by vibration is required when the assembled battery 1 is used for an application such as an automobile.

  Therefore, in the present invention, the metal film 7 included in the resin-metal composite laminate film 6 used as the battery exterior material is caused to function as a metal casing, and the metal film 7 is connected to the ground. The metal film 7 originally prevents moisture from entering the exterior material, but in the present invention, a function of performing electromagnetic shielding is newly added to the metal film 7. The electromagnetic shield is basically achieved by covering an object (here, the assembled battery 1) that dissipates electromagnetic waves with a metal member. In this sense, the metal film 7 is based on the present invention because it satisfies this condition.

  The connection between the metal film 7 and the ground wire 25 is as follows. That is, as shown in FIG. 1B, the pin-like conductive member 21 is penetrated from the upper side to the lower side in the heat-sealed portion 10 where the high-voltage tabs 4 and 5 are not taken out. Since there is the head portion 22, the pin portion 23 does not come out downward even if it is penetrated vigorously. Conversely, the conductive member 21 may be penetrated from below to above. In addition, in the heat-sealed portion where the conductive member cannot be penetrated, in addition to the heat-fused portion 10 where the high voltage tabs 4 and 5 are taken out, the heat-fused portion where the voltage detection terminal is taken out. There is a landing part 10. For this reason, unless otherwise specified below, it is assumed that “the part where the high voltage tab is taken out” includes “the part where the voltage detection terminal is taken out”, and “the part where the high voltage tab is not taken out” "Includes" a part from which the voltage detection terminal is not taken out ".

  The conductive member 21 includes a head portion 22 and a pin portion 23 having a sharp tip. As shown in FIG. 1B, in the heat-sealed portion 10 where the high voltage tabs 4 and 5 are not taken out, the metal film 7, the resin film 8, the resin film 8, and the metal film 7 are arranged in four layers from above. Since they overlap, when the pin-shaped conductive member 21 is penetrated from above, the upper and lower metal films 7 and 7 and the pin portion 23 come into contact with each other with the conductors. This contact site forms a conductive connection point.

  One end (the left end in FIG. 1B) of the ground wire 25 is connected to the conductive member 21 in contact with the upper and lower two metal films 7, 7. The other end (right end in FIG. 1B) of the ground wire 25 is fixed to the vehicle body by bolting the other end of the ground wire and the vehicle body (not shown). The reason for fixing by bolting is to make the assembled battery 1 detachable from the vehicle body.

  Thus, according to 1st Embodiment, since the metal film 7 as an exterior material has a function of an electromagnetic shield, it is not necessary to form a ground by a metal housing, and the lightweight and compact assembled battery 1 Can be formed.

  Moreover, since the ground connection location to the exterior material is the heat fusion part 10 (site joined by thermal fusion), it is possible to effectively form the ground while maintaining the airtightness inside the exterior material. it can.

  Further, the conductive member 21 and the metal film 7 can be obtained by simply passing a sharp (sharp) conductive member 21 from the upper and lower sides into the heat-sealed portion 10 where the two resin-metal composite films 6 and 6 are joined. Thus, a conductive connection point can be formed.

  In addition, according to the first embodiment, the battery element 2 is a bipolar secondary battery element 3 in which a plurality of unit cells are stacked. It can be performed.

(Second and third embodiments)
FIGS. 4 and 5 are schematic plan views of the assembled battery 1 of the second and third embodiments, which replace FIG. 2 of the first embodiment. The same parts as those in FIG. In the embodiment, since the bipolar secondary battery element 3 is formed in a rectangular and flat plate shape as a whole, the heat fusion part 10 has a frame shape having four sides as shown in FIGS. Yes. Then, a high voltage tab or a voltage detection terminal is taken out from any one side to the outside of the exterior material. However, depending on the shape of the bipolar secondary battery element 3, the heat fusion part 10 can be a frame shape having three or five sides. In short, the planar shape of the heat-sealing part 10 is not limited to a frame shape having four sides, and may be a frame shape having at least three sides. As shown in FIGS. 4 and 5, the heat-sealed portion 10 includes an upper side (upper side in the horizontal direction), a lower side (lower side in the horizontal direction), a right side (right side in the vertical direction), and a left side ( 4 on the left side in the vertical direction).

  In the second embodiment, the position of the heat fusion part 10 through which the pin part 23 of the conductive member 21 penetrates is variously changed. In the first embodiment, the position of the heat fusion part 10 that penetrates the pin part 23 of the conductive member 21 is the upper right of the right frame (see FIG. 2), but the heat fusion part that penetrates the pin part 23 of the conductive member 21 As shown in FIG. 4, the position 10 may be basically any position of the upper frame, the lower frame, the right frame, and the left frame as long as it is the heat fusion part 10.

  In the third embodiment, the pin portion 23 of the conductive member 21 is attached to the side to which the portion from which the high-voltage tabs 4 and 5 are taken out or the side to which the voltage detection terminal 26 is taken out. It is made to penetrate. That is, in FIGS. 5A and 5B, the left side to which the part from which the pair of high voltage tabs 4 and 5 are taken out belongs, and in FIG. 5C, the right side to which the part from which the voltage detection terminal 26 is taken out belongs. The pin portion 23 of the conductive member 21 is passed through. Here, the voltage detection terminal 26 is a terminal for detecting the voltage of each unit cell.

  According to the third embodiment, of the frame-shaped heat fusion part 10 (the part joined by heat fusion) having four sides, the part from which the high voltage tabs 4 and 5 or the voltage detection terminal 26 are taken out belongs. Since the conductive member 21 is passed through the side, due to the physical anchor effect of the conductive member 21, the side of the side to which the high-voltage tabs 4 and 5 or the voltage detection terminal 26 to which the voltage detection terminal 26 is taken out is relatively difficult to maintain the seal strength. Bonding strength can be increased.

  In the heat-sealing part 10, the heat-sealed two upper and lower resin-metal composite laminate films 6, 6 are sealed by a force that causes peeling. On the other hand, when the conductive member 21 is passed through the heat-sealing part 10, the frictional force generated between the pin part 23 and the upper and lower two resin-metal composite laminate films 6, 6 causes the above-mentioned peeling. To join. That is, the friction force acts as a force for maintaining the heat-sealed state. The physical anchor effect of the conductive member 21 is that the frictional force acts as a force for maintaining the heat-sealed state.

(Fourth embodiment)
FIG. 6 is a schematic longitudinal sectional view of the assembled battery 1 as seen from a portion where the high voltage tab of the fourth embodiment is not taken out, and replaces FIG. 1B of the first embodiment. The same parts as those in FIG. 1B are denoted by the same reference numerals.

  4th Embodiment differs in 1st Embodiment shown by FIG. 1B, and an exterior material. That is, the resin-metal composite laminate film 6 of the fourth embodiment includes a film 7 of a metal (including an alloy) such as aluminum, stainless steel, nickel, and copper, and a film 8 of a resin (insulator) such as a polypropylene film, A resin (insulator) film 9 such as a polypropylene film is joined. That is, it has a three-layer structure in which the metal film 7 is sandwiched between the two resin films 8 and 9 from both sides.

  The two resin films 8 and 9 on both sides have the same expansion coefficient. The metal film and the resin film have greatly different expansion rates. In order to make a two-layer resin-metal composite laminate film 6 by laminating a resin film and a metal film, the two films are pasted together with an adhesive, but the expansion rate differs greatly between the metal film and the resin film. The bonded resin-metal composite laminate film 6 is rounded, resulting in poor workability. On the other hand, since the resin-metal composite laminate film 6 of the fourth embodiment is a three-layer film in which the metal film 7 is sandwiched between two resin films 8 and 9 having the same expansion coefficient, the resin-metal composite film is formed. The laminate film 6 is not rounded and has good workability.

  Also in 4th Embodiment, the electroconductive member 21 is penetrated to the heat-sealing part 10 of the site | part from which the high voltage tabs 4 and 5 are not taken out. The operational effects of the fourth embodiment are the same as the operational effects of the first embodiment.

  Unlike the first embodiment, the exterior material of the fourth embodiment has resin films 9 and 9 exposed on the surface. As described above, even in the case of the resin-metal composite laminate film 6 in which the resin films 9 and 9 are exposed on the surface, the conductive film 21 can be conductive by simply passing the pointed (sharp) conductive member 21 through the heat fusion portion 10. The member 21 and the two metal films 7 and 7 inside can be easily conducted.

(Fifth embodiment)
FIG. 7 is a schematic longitudinal sectional view of the assembled battery 1 as seen from a portion where the high voltage tab of the fifth embodiment is not taken out, and replaces FIG. 6 of the fourth embodiment. The same parts as those in FIG. 6 are denoted by the same reference numerals.

  In the fifth embodiment, the pin portion 23 of the conductive member 21 is provided with a pointed retaining portion 24 (referred to as “return”) on the pin portion 23 of the conductive member 21 so that the pin portion 23 of the conductive member 21 does not come off from the heat fusion portion 10. Is. As a shape of the retaining portion 24, a mode as shown in FIG. That is, FIG. 8A is an enlarged view of the conductive member 21 shown in FIG. 7, and is provided with a retaining portion 24 having a pointed tip, one on each side of the pin portion 23.

  On the other hand, FIG. 8 (b) shows a structure in which one retaining portion 24 is provided only on one side of the pin portion 23, and FIG. 8 (c) shows two retaining portions 24 that are pointed obliquely upward to the right. FIG. 8 (d) shows an arrangement that is provided on one side of the pin portion 23 side by side and is further opposite to the pin portion 23 with two retaining portions 24 that are pointed toward the upper left in the vertical direction with respect to FIG. 8 (c). It is also provided on the side.

  The reason why the retaining portion 24 is provided on the outer periphery of the pin portion 23 is to enhance the physical anchor effect of the conductive member 21. That is, even if it tries to move in the direction opposite to the direction in which the pin portion 23 penetrates. The retaining portion 24 prevents the pin portion 23 from moving. In other words, in addition to the frictional force, the force that the retaining portion 24 prevents the movement of the pin portion 23 acts as a force that maintains the state of heat fusion.

  According to the fifth embodiment, the conductive member 21 includes a pin portion 23 and a head portion 22 having a diameter larger than the diameter of the pin portion 23, and the heat fusion portion 10 (portion joined by heat fusion). Since at least one retaining portion 24 that prevents the pin portion 23 from moving in the direction opposite to the direction in which the conductive member 21 penetrates is provided on the outer periphery of the pin portion 23 that penetrates the pin portion 23, the seal strength is relatively maintained. The bonding strength of the heat-sealed portion 10 (portion bonded by thermal fusion) near the portion where the high-voltage tabs 4 and 5 that are difficult to do is removed is that of the conductive member 21 that does not have the retaining portion 24. It is larger than the case, and a ground connection with high vibration resistance can be formed.

(Sixth embodiment)
FIG. 9 is a schematic longitudinal cross-sectional view of the assembled battery 1 as seen from a portion where the high voltage tab of the sixth embodiment is not taken out, and replaces FIG. 6 of the fourth embodiment. The same parts as those in FIG. 6 are denoted by the same reference numerals.

  In the sixth embodiment, the conductive member 21 is composed of one head 22 and a plurality of pin portions 23 standing from the head 22, and the conductive member 21 as a whole is shaped like a sword mountain. Specifically, as shown in FIG. 9, three pin portions 23, 23, 23 from one head 22 stand in a row in the conductive member 21 downward. The heat-bonding portion 10 in a portion where the high-voltage tabs 4 and 5 are not taken out with the conductive member 21 having the shape in which the three pin portions 23, 23, and 23 are arranged in a row so that the pin portion is located below. To penetrate from top to bottom. Conversely, the conductive member 21 may be penetrated from below to above.

  FIG. 10 shows another embodiment of the conductive member 21. What is necessary is just to stand at least two pin parts 23 from one head 22. In the conductive member 21 shown in FIG. 10A, ten pin portions 23 are erected in a row from one head portion 22. In the conductive member 21 shown in FIGS. 10B, 10 </ b> C, and 10 </ b> D, a plurality of pin portions 23 are erected in a plane from one head 22.

  As a method of connecting the conductive member 21 and the ground wire 25, it is as shown in FIG. That is, the head 22 and the ground wire 25 are connected to each other by fastening the bolt 26 and the nut 27. By removing the bolt 26 and the nut 27 and removing them, the head 22 and the ground wire 25 are disconnected. The reason for such a connection method is to make the assembled battery 1 and the conductive member 21 detachable from the vehicle body.

  The reason why a plurality of pin portions 23 are provided for one head portion 22 is to increase the number of conductive connection points and increase the physical anchor effect of the conductive member 21. That is, when there are a plurality of pin portions 23 for one head portion 22, the number of conductive connection points becomes a plurality of times as compared with the case where there is only one pin portion. Further, the frictional force between the plurality of pin portions 23 and the upper and lower two resin-metal composite laminate films 6, 6 is larger than the case of only one pin portion 23 for one head 22. . This increased frictional force acts as a force that maintains the heat-sealed state. In FIG. 9 of the sixth embodiment as well, the conductive member 21 is made to penetrate the heat-sealed portion 10 where the high-voltage tabs 4 and 5 are not taken out.

  According to the sixth embodiment, since at least two pin portions 23 are provided for one head portion 22, more conductive connections than when only one pin portion 23 is provided for one head portion 22. The heat fusion part 10 (bonded by heat fusion) near the portion where the high voltage tabs 4 and 5 or the voltage detection terminal 26 from which the point can be formed and the seal strength is relatively difficult to maintain is taken out. The bonding strength of the part) is increased, and a ground connection with high vibration resistance can be formed.

(Seventh embodiment)
FIG. 11 is a schematic vertical cross-sectional view of the assembled battery 1 as seen from a portion where the high voltage tab of the seventh embodiment is not taken out, and replaces FIG. 9 of the sixth embodiment. The same parts as those in FIG. 9 are denoted by the same reference numerals.

  In the seventh embodiment, two conductive members 21 shown in FIG. 9 are prepared, and one conductive member 21 is pinned from above to the heat fusion part 10 where the high voltage tabs 4 and 5 are not taken out. With the portion 23 facing downward and the other conductive member 21 from below with the pin portion 23 facing upward, the two upper and lower conductive members 21 and 21 are penetrated through the heat fusion portion 10. is there. In this case, the space | interval between the pin part 23 and the pin part 23 is defined so that the pin part 23 from upper direction and the pin part 23 from the downward direction may be located alternately.

  In the seventh embodiment, when distinguishing between the upper and lower conductive members 21, 21, the upper conductive member is referred to as "first conductive member 21A" and the lower conductive member is referred to as "second conductive member 21B". .

  As a method of connecting the upper two conductive members 21 and 21 and the ground wire 25, another aspect is shown in FIG. However, FIG. 12 shows only the conductive member, and the heat-sealed portion is not shown.

  Specifically, in FIG. 12A, the head 22 of the first conductive member 21 </ b> A is fastened by fastening the head 22 of the first conductive member 21 </ b> A and one end (left end in the figure) of the ground wire 25 with a bolt 26 and a nut 27. The part 22 and the ground wire 25 are connected. By removing the bolt 26 and the nut 27 and removing them, the head portion 22 of the first conductive member 21A and the ground wire 25 can be disconnected.

  In FIG. 12B, the female member 33 of the snap member 31 is attached to the right end of the first conductive member 21A, and the male member 32 of the snap member 31 is attached to the right end of the second conductive member 21B. The first conductive member 21A and the second conductive member 21B can be attached and detached.

  The snap member 31 includes a male member 32 and a female member 33, and the male member 32 attached to the head portion 22 of the second conductive member 21B is attached to the head portion 22 of the first conductive member 21A. The first conductive member 21A and the second conductive member 21B are fixed by being fitted. Further, by disengaging the male member 32 from the female member 33, the engagement between the first conductive member 21A and the second conductive member 21B can be released.

  Thus, the material of the snap member 31 that allows the first and second conductive members 21A and 21B to be attached and detached may be either resin or metal. When the material of the snap member 31 is resin, one end (the left end in FIG. 12B) of the ground wire 25 is connected to the head 22 of the first conductive member 21A. When the material of the snap member 31 is metal, one end (the left end in FIG. 12B) of the ground wire 25 can be connected to the snap member 31.

  According to the seventh embodiment, the first and second conductive members 21 </ b> A from the upper and lower surfaces of the thermal fusion part 10 (parts joined by thermal fusion) where the high voltage tabs 4, 5 are not taken out. Since 21B is penetrated, more conductive connection points are formed than when the conductive member 21 is penetrated from one side of the thermal fusion part 10 (part joined by thermal fusion), and the crimping structure from above and below. Since the high voltage tabs 4 and 5 that are relatively difficult to maintain the seal strength are relatively difficult to maintain, it is possible to join the heat fusion part 10 (the part joined by thermal fusion). The strength is increased, and it is possible to form a ground connection with high vibration resistance.

(Eighth embodiment)
FIG. 13A is a schematic longitudinal sectional view of the assembled battery 1 as seen from the site where the high voltage tab of the eighth embodiment is taken out, and FIG. 13B is a schematic diagram of the assembled battery 1 as seen from the site where the high voltage tab of the eighth embodiment is not taken out. It is a longitudinal cross-sectional view. Also in the eighth embodiment, as shown in FIG. 13B, the pin-shaped conductive member 21 is penetrated from the upper side to the lower side in the heat-sealed portion 10 where the high-voltage tabs 4 and 5 are not taken out. FIG. 13B replaces FIG. 6 of the fourth embodiment. The same parts as those in FIGS. 3 and 6 are denoted by the same reference numerals.

  In the eighth embodiment, the conductive member 21 is connected to the ground wiring (that is, the wire mesh layer 17) in the two high-power wirings 13, 14 connected to an external device such as an electric circuit that performs a switching operation like the inverter 12. It is intended to be connected. That is, as shown in FIG. 13A, two high-power wirings 14 and 15 with electromagnetic shield have inverters (not shown) at one end (lower end in the figure) at the high-power tabs 4 and 5 and other ends (upper end in the figure). 12 is connected. In addition, the wire mesh layers 17 and 17 of the two high-power wirings 14 and 15 with electromagnetic shield are grounded through one ground wire 18. As shown in FIG. 13B, the ground wire 25 connected to the conductive member 21 is connected to the ground wire 18.

  When the assembled battery 1 and the two high-power wirings 14 and 15 with electromagnetic shield are individually grounded, a loop current may flow. However, in the eighth embodiment, the assembled battery 1 and the two high-power wirings 14 with electromagnetic shielding and 15 is grounded at one place, so that the loop current can be avoided and the electromagnetic shielding effect can be improved.

  According to the eighth embodiment, the high-power wirings 14 and 15 with electromagnetic shield for connecting the high-power tabs 4 and 5 to an external device are provided, and the wire mesh layer 17 of the high-power wirings 14 and 15 with electromagnetic shield (inside the high-power wiring with electromagnetic shield) Since the conductive member 21 is connected to the ground wire), the ground wires 14 and 15 of the high-power wiring with electromagnetic shield and the ground wire 25 of the assembled battery 1 can be set to the same potential, and the high-power wiring 14 with electromagnetic shield is provided. , 15 and the assembled battery 1 can be more efficiently removed than electromagnetic noise (radiation of electromagnetic waves) generated from the assembled battery 1 than when the batteries are grounded individually.

(Ninth embodiment)
FIG. 14 is a schematic perspective view of the ninth embodiment showing an enlarged view of the vicinity of one of the high-voltage tabs (for example, the high-voltage tab 4) of the assembled battery 1 taken out from the exterior material. The same parts as those in FIG. 6 of the fourth embodiment are denoted by the same reference numerals. In the ninth embodiment, two conductive members 21 and 21 are used. In order to distinguish the two, the conductive member on the upper right in FIG. 14 is referred to as “third conductive member 21C”, and the conductive member in the lower left is referred to as “fourth conductive member 21D”.

  In the ninth embodiment, on the premise of the eighth embodiment shown in FIGS. 13A and 13B, the connection of the high-voltage wiring with electromagnetic shield to the high-power tab and the grounding of the conductive member 21 are integrally performed. .

  The third conductive member 21C and the fourth conductive member 21D are fixed in advance on the terminal block 31 formed of an insulating material (for example, plastic) with a predetermined width so that the pin portion 23 faces upward. 3. The fourth conductive members 21C and 21D are connected to each other by the ground wire 25. The ground wire 25 is formed by coating or the like on the terminal block 31. In FIG. 14, the ground wire 25 is formed in a U-shape.

  The terminal block 31 is heat-sealed so that the third and fourth conductive members 21C and 21D come across the heat-sealing portion 10 where the high-power tab 4 (one of the high-power tabs) is taken out. The terminal block 31 is arranged so as to be below the portion 10, and the third and fourth conductive members 21 </ b> C and 21 </ b> D are directed upward from below to the heat-sealed portions 10 on both sides of the portion where the high-voltage tab 4 is taken out. To penetrate. Thereafter, one end (the left end in FIG. 14) of the high-power wiring 15 with electromagnetic shield is connected to the high-power tab 4 and the wire mesh layer 17 of the high-power wiring 15 with electromagnetic shield is connected to the ground wire 25. The cylindrical member passing through the high voltage tab 4 in the vertical direction is a bolt 32 for fastening.

  Although not shown in the figure, in the same manner as in FIG. 14, the portion where the high-power wiring 14 with electromagnetic shield is connected to the other high-power tab 5, and the wire mesh layer 17 of the high-power wiring 14 with electromagnetic shielding (high-power wiring with electromagnetic shielding). The part to be connected to the ground wiring) is configured on the same terminal block.

  According to the ninth embodiment, the portion connecting the high-voltage wirings 14 and 15 with electromagnetic shield to the high-voltage tabs 4 and 5 and the wire mesh layer 17 of the high-voltage wirings 14 and 15 with electromagnetic shielding (high power with electromagnetic shielding). The portion connected to the ground wiring in the wirings 14 and 15 is configured in the same terminal block 31. As a result, as shown in FIG. 14, it is possible to simultaneously perform both high-power connection (connection of the high-power tab 4 and high-power wiring 14 with electromagnetic shield) and ground connection of the assembled battery 1 with one terminal block 31. The ground connection can be made very simply.

(Example)
Evaluation of a bipolar secondary battery (stacked battery) using an assembled battery was performed as follows.

<Production of bipolar electrode>
[Create positive electrode layer]
A positive electrode slurry was prepared by mixing 85% by weight of LiMn204 as a positive electrode active material, 5% by weight of acetylene black as a conductive auxiliary agent, and 10% by weight of polyvinylidene fluoride (PVDF) as a binder. N-methyl-2-pyrrolidone (NMP) was added as a slurry viscosity adjusting solvent until the viscosity became optimum for the coating process.

  The positive electrode slurry was applied to one side of a current collector 32 made of SUS foil having a thickness of 20 μm and dried to form a positive electrode 33 having a 30 μm electrode layer.

[Create negative electrode layer]
A negative electrode slurry was prepared by mixing 90 wt% of hard carbon as a negative electrode active material and 10 wt% of polyvinylidene fluoride (PVDF) as a binder. N-methyl-2-pyrrolidone (NMP) was added as a slurry viscosity adjusting solvent until the viscosity became optimum for the coating process.

  The negative electrode slurry was applied to the opposite surface of the SUS foil current collector 32 coated with the positive electrode 33 and dried to form a negative electrode 34 having a 30 μm electrode layer. The bipolar electrode 31 was formed by forming the positive electrode 33 and the negative electrode 34 on both surfaces of the current collector 32 of SUS foil.

  The bipolar electrode 31 was cut to a size of 160 × 130 mm, and the outer peripheral portion of both the positive electrode 33 and the negative electrode 34 was peeled off by 10 mm to expose the surface of the current collector 32 of SUS foil. Thus, a bipolar electrode 31 having an electrode surface area of 140 × 110 mm and an exposed SUS foil current collector 32 of 10 mm on the outer peripheral portion was produced. FIGS. 15A, 15B, and 15C are a plan view, a back view, and a cross-sectional view of the bipolar electrode 31, respectively.

<Formation of electrolyte layer>
90% by weight of LiPF6 containing 1 ml of polyethylene carbonate (PC) -ethylene carbonate (EC) at a mixing ratio of 1: 1 as the electrolyte (boiling point is 242 ° C.), and 10% of hexafluoropropylene (HFP) copolymer as the host polymer Polyvinylidene fluoride (PVDF) -hexafluoropropylene (HFP) was mixed at a ratio of 10 wt% to prepare an electrolytic solution.

  Dimethyl carbonate (DMC) was added as a viscosity adjusting solvent until the viscosity became optimum for the coating process to prepare a pregel electrolyte. The pregel electrolyte was applied to the electrode portions of the positive electrode 33 and the negative electrode 34 on both sides of the current collector 32, and dimethyl carbonate (DMC) was dried to complete the bipolar electrode 31 infiltrated with the gel electrolyte.

<Formation of seal part precursor>
Using a dispenser, a seal portion precursor 35 was applied to the current collector peripheral portion 32a, which is an unapplied portion of the outer periphery of the positive electrode 33, as shown in FIG. A one-part uncured epoxy resin was used as the seal portion precursor 35. Here, FIGS. 16A and 16B are a plan view and a cross-sectional view of the bipolar electrode 31 for explaining a state where the seal portion precursor 35 is applied.

  Next, a 170 × 140 mm separator 36 (polyethylene separator: 12 μm, melting point: 134 ° C.) was placed on the positive electrode side so as to cover all of the current collector 32 of SUS foil. The separator 36 is porous or sponge-like, and the separator 36 is also impregnated with the gel electrolyte.

  Then, using the dispenser on the current collector peripheral portion 32a, which is the portion where the electrode is not applied (the same portion as the portion where the seal portion precursor 35 is applied) from above the separator 36, the seal portion precursor is overlapped as shown in FIG. Body 35 (one-part uncured epoxy resin) was applied. FIGS. 17A and 17B are a plan view and a cross-sectional view of the bipolar electrode 31 for explaining the state covered with the separator 36.

<Lamination process>
A bipolar battery structure in which 12 unit cells were stacked in the vertical direction was manufactured by stacking 13 bipolar electrodes 31 manufactured as shown in FIG. 17 in the vertical direction.

<Bipolar battery press>
The bipolar battery structure was hot-pressed with a hot press machine 51 at a surface pressure of 1 kg / cm 2 and 80 ° C. for 1 hour to cure the uncured seal portion (epoxy resin). This step makes it possible to press and cure the seal portion to a predetermined thickness. As shown in FIG. 18, the seal portion 42 is formed by the seal portion precursor 35 by hot pressing from above and below the bipolar battery structure. Thus, the bipolar secondary battery element 45 as one lump, in which 12 unit cells 41 are connected in series, was completed. Here, FIG. 18 is a longitudinal sectional view of the bipolar secondary battery element 45.

  For the sake of simplicity, FIG. 18 shows a bipolar secondary battery element 45 in which four unit cells 41 are connected in series by stacking five bipolar electrodes 31 in the vertical direction. As shown in FIG. 18, one unit cell 41 includes an element between two adjacent current collectors 32, 32, that is, a negative electrode 34, a separator 36 soaked with gel electrolyte, and a positive electrode 33. It is configured.

<Packaging process>
As shown in FIGS. 19 and 20, the bipolar secondary battery element 45 produced by the above method is further stacked in series to form a battery element 47 as a lump. A pair of high-power tabs 4 and 5 are arranged on each other, and the pair of high-power tabs 4 and 5 and the eight bipolar secondary battery element 45 are hermetically sealed with an exterior material, so that a bipolar for driving a motor is obtained. The assembled battery 1 (average voltage 360 V) of the type secondary battery was completed. Here, FIG. 19 is a schematic longitudinal sectional view of the assembled battery 1 of a bipolar secondary battery, and FIG. 20 is a schematic plan view of the assembled battery 1 of a bipolar secondary battery.

  The ground shape of the assembled battery 1 of the bipolar secondary battery thus completed (hereinafter also simply referred to as “assembled battery”) was combined as shown in Table 1 below. And the weight measurement of the assembled battery 1 of Comparative Examples 1 and 2 and Examples 1-6 was implemented like Table 1, and the weight comparison in each earth | ground shape was performed.

  In the battery pack of Comparative Example 1, a stainless steel metal casing was used instead of a resin-aluminum composite laminate film (abbreviated as “aluminum laminate film” in Table 1). Further, the assembled battery of Comparative Example 2 uses a resin-aluminum composite laminate film for the exterior, but is further covered with a stainless steel metal casing to take a ground.

  Comparing the assembled battery weights of the assembled battery of Comparative Example 1 and the assembled batteries (bipolar secondary batteries) of Examples 1 to 5, the assembled batteries (bipolar secondary batteries) of Examples 1 to 5 are very compact. And it is lightweight. However, it can be seen that, when covered with a metal casing (stainless steel) and an electromagnetic shield is formed as in the assembled battery of Comparative Example 2, the merit of using a resin-aluminum composite laminate film as an exterior material is halved.

  Moreover, when the assembled battery weight of the assembled battery including the assembled battery of Comparative Example 2 and the plastic casing of Example 6 is compared, an electromagnetic shield is formed with a resin-aluminum composite laminate film, and the assembled battery is assembled with the plastic casing. It was also found that the weight of Example 6 in which was fixed was significantly lighter than that of Comparative Example 2. Thus, according to the assembled battery of Example 6, since the case for fixing the assembled battery is a plastic (resin) housing, it is possible to form an assembled battery that is lightweight and has high vibration resistance.

  Therefore, the case was included by using the resin-aluminum composite laminate film as an exterior material as in Examples 1 to 5 and forming an earth with the aluminum film (metal film) of the resin-aluminum composite laminate film. The assembled battery was found to be significantly lighter.

  Next, resistance measurement between the ground wire and the resin-aluminum composite laminate film was performed on the assembled batteries of Examples 1 to 5. Further, vibration was applied to the assembled batteries of Examples 1 to 5 for a long time, and then resistance measurement was performed once again. The resistance before vibration was taken as 100%, and the resistance (%) after vibration was summarized in Table 2 below. In addition, the vibration test was performed by applying a monotonous vibration of 50 Hz and an amplitude of 3 mm in a perpendicular direction to the assembled battery for 200 hours.

  When the assembled battery of Example 1 (see FIG. 6) and the assembled battery of Example 2 (see FIG. 7) are compared, an increase in resistance to vibration is suppressed by having a retaining portion 24 on the outer periphery of the pin portion 23. I found out that This is considered that the increase in resistance is suppressed by the retaining portion 24 being caught by the metal portion (metal film) of the resin-aluminum composite laminate film. Further, when the assembled battery of Example 1 (see FIG. 6) and the assembled battery of Example 3 (see FIG. 9) are compared, the increase in resistance is suppressed when there are two conductive members 21 above and below the heat-sealed portion. I found out that This is considered that the vibration resistance is improved by increasing the number of contact points between the resin-aluminum composite laminate film and the conductive member.

  Furthermore, when the assembled battery of Example 3 (see FIG. 9) and the assembled battery of Example 4 (see FIG. 11) are compared, the ground shape in which the conductive member is penetrated and fixed from both surfaces of the heat fusion part 10 is better. Further, it was found that the increase in resistance can be suppressed.

  In the assembled battery of Example 5 (see FIG. 14), the best shape of the earth shape is formed, and the resistance increase is further suppressed, and the earth of the high-voltage wiring with electromagnetic shield and the aluminum of the resin-aluminum composite laminate film It has a simpler structure by bonding a film (metal film). In addition, since it is possible to form a ground with a very short distance from a ground such as a power converter (motor), the electromagnetic shielding performance is further enhanced.

  Next, with respect to the assembled battery samples of Example 1 to Example 5 replaced with a stainless steel plate instead of the battery element 47 shown in FIG. 19, the ground shape is installed on the side to which the high voltage tab takeout part belongs, Each having a ground shape installed on a side to which the high voltage tab take-out portion does not belong was prepared. Here, “installing a ground shape” means, for example, passing a sharp conductive member at the tip through the heat-sealed portion as shown in FIG.

  Further, “side with a high-power tab take-out portion” and “side without a high-power tab take-out portion” will be described. In FIG. 20, the heat fusion part 10 is a square frame shape. When this square frame-shaped heat fusion part 10 is replaced with a simple quadrilateral having four sides, it consists of two vertical sides running left and right and two horizontal sides running up and down. In FIG. 20, the high power tabs 4 and 5 are taken out from the two vertical sides on the left and right, and the high power tabs 4 and 5 are not taken out from the two top and bottom horizontal sides. Accordingly, “the side where the high-power tab take-out portion is present” means the two vertical sides on the left and right, and “the side where there is no high-power tab take-out portion” means the two upper and lower horizontal sides. Although it is referred to as “side”, it is substantially the heat-sealed portion 10.

  The following table shows the results of measuring the pressure when the tube was introduced into the resin-aluminum composite laminate film of this assembled battery sample and the internal pressure was increased by feeding air to release the internal pressure. It was summarized in 3. However, the pressure when the internal pressure is released is 100% with respect to the battery pack sample of Example 1 in which the ground shape is installed on the side to which the high voltage tab take-out portion belongs, and the internal pressure of other battery pack samples is released. The pressure at that time was expressed in%.

  In any of the assembled battery samples from Example 1 to Example 5, it was difficult to maintain the sealing strength, the heat fusion part of the side to which the high-voltage tab take-out part belongs was opened and the internal pressure was released. For the assembled battery samples, the ground shape is opened when the internal pressure is higher when the ground shape is installed on the side to which the high-voltage tab take-out part belongs than when the ground shape is installed on the side to which the high-power tab take-out part does not belong. It was. From this result, it was found that the adhesive strength of the side to which the high-power tab take-out portion to which it is difficult to maintain the seal strength is increased by installing the ground shape on the side to which the high-power tab take-out portion belongs. This is because a grounding shape is installed, that is, a conductive member having a sharp tip as shown in FIG. It is considered that the bonding strength of the side (heat-sealed portion) to which the high-voltage tab takeout portion belongs is increased.

DESCRIPTION OF SYMBOLS 1 Battery assembly 2 Battery element 3 Bipolar secondary battery element 4, 5 High-voltage tab 6 Resin-metal laminate film 7 Metal film 8, 9 Resin film 10 Thermal fusion part 21 Conductive member 23 Pin part 25 Ground wire

Claims (9)

A resin-metal composite film made by laminating a resin film and a metal film is used as an exterior material, and the battery element is covered with the resin-metal composite film so that a margin part is protruded from the outer periphery of the battery element.
In the battery in which the battery element is housed and sealed inside the exterior material by joining the upper and lower margins protruding to the outer periphery by thermal fusion,
A battery characterized in that a conductive member is passed through the part bonded by heat fusion and the conductive member is connected to ground. The part joined by the thermal fusion has a frame shape having at least three sides, and includes a high voltage tab or a voltage detection terminal that is taken out from the exterior material from any one side,
2. The battery according to claim 1, wherein the conductive member is passed through a side to which a portion from which a high voltage tab or a voltage detection terminal is taken out belongs. The conductive member comprises a pin portion and a head having a diameter larger than the diameter of the pin portion,
It has at least one retaining portion for preventing the pin portion from moving in the direction opposite to the direction of penetrating the conductive member on the outer periphery of the pin portion penetrating the portion bonded by the heat fusion. The battery according to claim 1 or 2, characterized in that:   The battery according to claim 3, wherein the battery has at least two pin portions with respect to the one head.   The battery according to any one of claims 1 to 4, wherein the conductive member is penetrated from both surfaces of the part joined by the thermal fusion. It is equipped with high-power wiring with an electromagnetic shield that connects the high-power tab to an external device,
The battery according to any one of claims 2 to 4, wherein the conductive member is connected to a ground wiring in the high-voltage wiring with electromagnetic shield.   The portion connecting the high-voltage wiring with electromagnetic shield to the high-voltage tab and the portion connecting the conductive member to the ground wiring in the high-voltage wiring with electromagnetic shielding are configured in the same terminal block. 6. The battery according to 6.   The battery according to any one of claims 1 to 7, wherein the case for fixing the battery is a resin casing.   The battery according to claim 1, wherein the battery element is a bipolar secondary battery element in which a plurality of single cells are stacked.

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