JP2005116235A - Laminate jacket battery, battery module, and battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate jacket battery having a gas exhaust mechanism sufficiently exhibiting a function for exhausting gas to the outside in abnormal circumstances even if pressure is applied to a power generation element, and to provide a battery module and a battery pack. <P>SOLUTION: The laminate jacket battery 11 has flexible laminate films 21, 22, a power generating element 31 sealed by heat sealing the outer peripheral part 23 of the laminate films, and a gas exhaust mechanism 50 installed in a heat sealed portion of the laminate films and exhausting gas to the outside by cleaving a heat sealed state in the outer peripheral part when gas generated inside the battery reaches the designated pressure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminated battery, a battery module, and an assembled battery.

  In recent years, as a power source of an electric vehicle (EV) that uses electricity as a power source or a hybrid car (HEV) that combines an engine and a motor, a battery covered with a laminate film, that is, a laminated exterior battery, from the viewpoint of weight reduction or the like. Is attracting attention.

  A laminate-clad battery generally includes a laminate film having flexibility, and the power generation element is sealed by heat-sealing the outer peripheral edge of the laminate film. The other end of the electrode lead whose one end is electrically connected to the power generation element protrudes outside the laminate film (see Patent Document 1).

  Patent Document 1 discloses a gas release mechanism that is disposed at a place other than the heat-sealed portion of the laminate film and opens when the gas generated in the battery reaches a predetermined pressure and releases the gas to the outside. Has been described.

For example, in the case of a laminated battery such as a lithium ion secondary battery in which a laminated power generation element in which a positive electrode plate, a negative electrode plate, and a separator are sequentially laminated is sealed, the distance between the electrodes is kept uniform. In order to maintain it, it is necessary to apply pressure to the power generation element and hold it down. For this reason, if the gas release mechanism is arranged at a place other than the heat-sealed portion of the laminate film, the gas release mechanism may be blocked when the battery is held down, and the function of releasing gas to the outside in the event of an abnormality. It cannot be fully demonstrated. Therefore, the power generation element cannot be pressed and pressed, and there is a possibility that the battery performance is deteriorated.
JP 2001-345081 A

  The present invention has been made in view of the problems associated with the above-described prior art, and includes a gas release mechanism that can sufficiently exert the function of releasing gas to the outside in the event of an abnormality even when pressure is applied to the power generation element. Another object of the present invention is to provide a laminated battery, a battery module, and an assembled battery.

The invention according to claim 1 for achieving the above object includes a laminate film having flexibility,
A power generation element sealed by heat-sealing the outer peripheral edge of the laminate film;
A gas that is disposed in the heat-sealed portion of the laminate film and releases the gas to the outside by dissociating the heat-sealed state of the outer peripheral edge when the gas generated in the battery reaches a predetermined pressure. And a release mechanism.

  According to the present invention, the outer peripheral edge of the laminated battery is heat-sealed, and the gas discharge mechanism is provided at the outer peripheral edge. The releasing function can be sufficiently exerted, and it is possible to improve the reliability at the time of abnormality while keeping the distance between the electrodes uniform to prevent the battery performance from being lowered. In addition, the direction in which the gas is released in the event of an abnormality can be easily set in advance, and the heat fusion part at the outer peripheral edge can be cleaved, so that the gas emission region can be sufficiently secured. .

  Embodiments of the present invention will be described below with reference to the drawings.

  In the present specification, “unit cell”, “battery module”, and “assembled battery” are respectively defined as follows. The “single cell” refers to a single battery, and in this specification, a battery in which a power generation element is sealed with a flexible laminate film, that is, a so-called laminated battery. “Battery module” refers to a battery in which a plurality of laminated exterior batteries are electrically connected. The “assembled battery” refers to a battery in which a plurality of battery modules are electrically connected. Each of “battery module” and “assembled battery” as well as “single cell” is used as a battery. The names “single cell”, “battery module”, and “assembled battery” are used to facilitate understanding of the difference in battery size.

(First embodiment)
FIG. 1A is a perspective view showing a laminated outer battery 11 according to the first embodiment of the present invention, FIG. 1B is a perspective view showing another form of the laminated outer battery 11a, and FIG. ) Is a plan view showing the laminated exterior battery 11, and FIGS. 2B and 2C are cross-sectional views taken along the line 2B-2B in FIG. 2A, respectively, and cross-sectional views taken along the line 2C-2C. .

  As shown in the drawing, the laminated battery 11 according to the first embodiment can be summarized as follows: a pair of laminate films 21 and 22 having flexibility and an outer peripheral edge portion 23 of the laminate films 21 and 22 are heat-sealed. Thus, the power generation element 31 is sealed, and positive and negative electrode terminals 41 and 42 having one end electrically connected to the power generation element 31 are provided. Each of the electrode terminals 41 and 42 is connected to the opposing end surface of the power generation element 31. The other ends of the electrode terminals 41 and 42 protrude outward from the outer peripheral edges of the laminate films 21 and 22. The laminated outer battery 11 of the present embodiment is further disposed in the heat-sealed portion of the laminate films 21 and 22, and when the gas generated in the battery reaches a predetermined pressure, the outer peripheral edge portion 23 is heat-sealed. It has a gas release mechanism 50 that cleaves the state and releases the gas to the outside. Details will be described below.

  The illustrated laminated exterior battery 11 is, for example, a lithium ion secondary battery, and a laminated power generation element 31 in which a positive electrode plate, a negative electrode plate, and a separator are sequentially laminated is sealed with laminate films 21 and 22.

  The laminate films 21 and 22 are generally composite sheets composed of two or more layers. As shown in FIGS. 2B and 2C, a seal layer 24, a metal layer 25 such as an aluminum laminate film, and a resin layer 26 forming an exterior are provided in order from the inside to the surface. doing. The seal layer 24 is formed from a heat-fusible resin. As the heat-fusible resin material, for example, a thermoplastic resin material such as polypropylene (PP) or polyethylene (PE) is applied.

  Each of the laminate films 21 and 22 has a substantially rectangular shape and covers the power generation element 31 so as to sandwich the power generation element 31. The pair of laminate films 21 and 22 are bonded to each other by heat fusion from the outside of the power generation element 31 to the film end portion. In the portion where the electrode terminals 41 and 42 protrude, the aluminum plate forming the electrode terminals 41 and 42 and the seal layer 24 are directly joined by heat fusion. Of the four sides 23a to 23d of the outer peripheral edge 23, the two sides 23a and 23c from which the electrode terminals 41 and 42 protrude are places where vibrations are transmitted through the electrode terminals 41 and 42 and a minute gap is likely to occur. . For this reason, in general, the tear strength at the sides 23a and 23c from which the electrode terminals 41 and 42 protrude is higher than the tear strength at the other two sides 23b and 23d. The tear strength at the sides 23a and 23c can be determined by, for example, subjecting the electrode terminals 41 and 42 to surface treatment, adjusting the material of the seal layer 24, or changing the method and conditions of heat sealing. It is higher than 23d. The outer peripheral edge portion 23 that is heat-sealed is also referred to as a seal portion 23.

  The gas release mechanism 50 is provided on a part of at least one side (the right side 23b in FIG. 2A) of the outer peripheral edge 23 of the laminate films 21 and 22, which is heat-sealed, that is, the seal part 23. In addition, the side 23a and 23c having the electrode terminals 41 and 42 are provided with the gas release mechanism on the side 23a (or 23d) instead of the sides 23a and 23c, and the vibrations are transmitted through the electrode terminals 41 and 42 as described above. Therefore, it is a place where a minute gap is likely to be generated and it is difficult to manage the strength, and in the direction of the electrode terminals 41 and 42, an electrical connection portion such as an electrode connection portion and an electronic component following the connection portion are arranged. This is because the possibility is high and it is not preferable in the gas discharge direction. This gas release mechanism 50 is configured by forming the shape of the heat-sealed portions of the laminate films 21 and 22 into a shape in which stress due to gas generated in the battery is concentrated. Specifically, as shown in FIGS. 2A and 2C, the gas release mechanism 50 forms a narrow portion 51 having a small seal width on a part of the right side 23b of the seal portion 23 and the narrow portion 51. It is comprised by forming the introducing | transducing part 52 which guides gas toward.

  The gas release mechanism 50 having such a configuration is simplified by setting the pattern shape of heat applied by a heat bar (not shown) for heat-sealing the right sides 23b of the laminate films 21 and 22 to a shape that matches the above-described shape. Can be formed. As shown in FIG. 2C, the seal layer 24 in a portion where no heat is applied is not sufficiently heat-sealed, and a gap forming the introduction portion 52 is formed between the seal layers 24.

  Next, the operation of the gas release mechanism 50 will be described.

  In the first embodiment, when gas is generated inside the battery due to an abnormality such as overcharge, the gas is guided toward the narrow portion 51 through the introduction portion 52. The stress due to the gas acts on the narrow portion 51 in a concentrated manner. And when the gas pressure in a battery reaches a predetermined pressure, the narrow part 51 will cleave a heat-fusion state and will discharge | release gas outside. Thereby, a situation such as a rupture of the laminate-cased battery 11 is prevented, and the reliability at the time of abnormality is improved. The predetermined pressure at which the gas release mechanism 50 breaks the heat-sealed state can be set as appropriate by changing the width of the narrowed portion 51, the heat-sealing conditions, etc., and is, for example, about 1 kgf / cm 2.

  The gas release mechanism 50 is disposed in the seal portion 23, but the seal portion 23 is very thin compared to the portion surrounding the power generation element 31. For this reason, even if the portion surrounding the power generation element 31 is pressed in the thickness direction, there is always a gap around the seal portion 23, so that the gas discharge mechanism 50 is not blocked. Therefore, even if pressure is applied to the power generation element 31, the function of releasing the gas to the outside in the event of an abnormality can be sufficiently exerted, and the distance between the electrode plates can be kept uniform to prevent the battery performance from deteriorating. Is possible. Further, since the gas release mechanism 50 is disposed in the seal portion 23, the direction in which the gas is released in the event of an abnormality can be easily set in advance.

  Furthermore, since the gas at the time of abnormality is discharged from the gas release mechanism 50 provided in a part of the seal portion 23, the gas discharge position at the time of abnormality can be set more accurately and easily.

  As described above, the laminated battery 11 according to the first embodiment is sealed by heat-sealing the flexible laminated films 21 and 22 and the outer peripheral edge 23 of the laminated films 21 and 22. The gas generating element 31 and the laminated films 21 and 22 are disposed in the heat-sealed portions, and when the gas generated in the battery reaches a predetermined pressure, the heat-sealed state of the outer peripheral edge portion 23 is cleaved to generate gas. And the gas release mechanism 50 that releases the gas to the outside, even if pressure is applied to the power generation element 31, the function of releasing the gas to the outside in the event of an abnormality can be sufficiently exerted, and the distance between the electrodes can be reduced. It is possible to improve the reliability at the time of abnormality while maintaining the uniformity to prevent the battery performance from deteriorating. Further, since the gas release mechanism 50 is disposed in the heat-sealed portions of the laminate films 21 and 22, the direction in which the gas is released in the event of an abnormality can be easily set in advance.

  In addition, since the gas release mechanism 50 is provided on a part of at least one side of the outer peripheral edge portion 23 of the laminate films 21 and 22 that are heat-sealed, the gas release position at the time of abnormality can be more accurately and easily determined. Can be set to

  Further, since the gas release mechanism 50 is formed by forming the shape of the heat-sealed portion of the laminate films 21 and 22 into a shape in which stress due to the gas generated in the battery is concentrated, It is possible to reliably exert the function of releasing the outside. Such a gas release mechanism 50 can be easily formed by setting a pattern shape of heat applied by a heat bar for heat-sealing the outer peripheral edge portion 23. Further, the gas release mechanism 50 having a simple cleavage structure can be formed without adding parts.

  In the first embodiment, the gas release mechanism 50 is formed by setting a part of the shape of the heat bar to a predetermined shape. However, the formation method of the gas release mechanism 50 is not limited to this case. For example, a similar gas release mechanism 50 can be formed by setting a part of the shape and width of the seal layer 24 to a predetermined shape and width. In this case, since it is not necessary to change the pattern of heat applied by the heat bar, the gas release mechanism 50 can be formed using the same heat bar as in the current situation.

  In addition to the arc shape shown in FIG. 2 (A), the shape of the introduction portion 52 may be any shape that can concentrate the stress due to the gas to the narrow portion 51, such as a shape that is sharpened toward the narrow portion 51. It can be modified as appropriate.

  Moreover, although the laminate-cased battery 11 in a form in which each of the positive and negative electrode terminals 41 and 42 is connected to the opposing end face of the power generation element 31 is shown, the positive and negative electrode terminals 41 are shown in FIG. , 42 are also applicable to a laminated battery 11a in a form in which both are connected to one end face of the power generation element 31.

(Second Embodiment)
FIG. 3 is a plan view showing a laminated battery 12 according to the second embodiment of the present invention.

  The laminated battery 12 according to the second embodiment, like the first embodiment, heat-bonds the flexible laminated films 21 and 22 and the outer peripheral edge 23 of the laminated films 21 and 22. The heat generating element 31 is sealed by the heat-sealed portions of the laminate films 21 and 22, and the gas generated in the battery reaches a predetermined pressure when the outer peripheral edge portion 23 is heat-sealed. A gas release mechanism 50 that cleaves and releases the gas to the outside. Further, the gas release mechanism 50 is provided on a part of the right side 23 b of the seal portion 23.

  However, the gas release mechanism 50 of the second embodiment is configured by making the adhesive strength by thermal fusion weaker than the adhesive strength by thermal fusion at other portions.

  In the laminate-coated battery 12 of the second embodiment, a part of the right side 23b of the seal portion 23 is a weak portion 53 that exhibits a tear strength that is weaker than the tear strength at other portions, and this weak portion 53 is a gas. The release mechanism 50 is used. Needless to say, the tear strength at the fragile portion 53 is sufficient to allow the laminate-coated battery 12 to operate normally.

  The gas release mechanism 50 having such a configuration can be formed by making the thermal fusion condition in a part of the heat bar for thermal fusion of the right side 23b of the seal part 23 different from the thermal fusion condition in the other part. The parameters of the heat fusion conditions include the heating temperature, the heating time, the applied pressure, etc. during the heat fusion treatment. Therefore, for example, by making the heating temperature in a part of the heat bar lower than the heating temperature in the other part, the part thermally fused by the low temperature part becomes the weak part 53, and this weak part 53 is used as the gas release mechanism 50. Can function.

  In the second embodiment, when the gas pressure in the battery reaches a predetermined pressure (for example, about 1 kgf / cm 2) at the time of abnormality, the gas is set to be weaker than the adhesive strength due to heat fusion at other parts. The part of the release mechanism 50 cleaves the heat-sealed state and releases the gas to the outside. Thereby, a situation such as a rupture of the laminate-cased battery 12 is prevented, and the reliability at the time of abnormality is improved.

  As in the first embodiment, since the gas release mechanism 50 is disposed in the seal portion 23, even if pressure is applied to the power generation element 31, the gas release mechanism 50 can sufficiently exert the function of releasing gas to the outside in the event of an abnormality. It is possible to prevent the battery performance from being lowered by keeping the distance between the electrodes uniform. Further, since the gas release mechanism 50 is disposed in the seal portion 23, the direction in which the gas is released in the event of an abnormality can be easily set in advance.

  Furthermore, since the gas at the time of abnormality is discharged from the gas release mechanism 50 provided in a part of the seal portion 23, the gas discharge position at the time of abnormality can be set more accurately and easily.

  As described above, the laminate-clad battery 12 of the second embodiment is similar to the first embodiment in that the distance between the electrodes is kept uniform to prevent the battery performance from being deteriorated and the reliability at the time of abnormality is maintained. The direction in which gas is released in the event of an abnormality can be easily set in advance.

  In addition, since the gas release mechanism 50 is provided on a part of at least one side of the outer peripheral edge portion 23 of the laminate films 21 and 22 that are heat-sealed, the gas release position at the time of abnormality can be more accurately and easily determined. Can be set to

  In addition, the gas release mechanism 50 is configured by making the adhesive strength by thermal fusion weaker than the adhesive strength by thermal fusion at other parts, so that the function of releasing the gas to the outside in the event of an abnormality is ensured. Can be demonstrated. Such a gas release mechanism 50 can be easily formed by setting the heat sealing conditions when the outer peripheral edge 23 is heat-sealed.

(Third to fifth embodiments)
4 (A) to 4 (C) are cross-sectional views showing portions of the gas release mechanism 50 in the laminate-clad batteries 13, 14, and 15 according to the third to fifth embodiments of the present invention. These cross-sectional views correspond to cross-sectional views taken along line 4-4 of FIG.

  As in the second embodiment, the gas release mechanism 50 of the third to fifth embodiments is configured by making the adhesive strength by thermal fusion weaker than the adhesive strength by thermal fusion at other portions. Has been.

  In the laminated battery 13 according to the third embodiment, as shown in FIG. 4A, the outer peripheral edge 23 of the laminate films 21 and 22 includes a heat-sealing seal layer 24, and gas is released. By partially cutting off the seal layer 24 at the site where the mechanism 50 is disposed, the adhesive strength by heat fusion at other sites is made weaker.

  In the illustrated example, a part of the sealing layer 24 of the upper laminate film 21 is cut away to form a gap 54, and the portion constituting the gas release mechanism 50 is made of an aluminum laminate film of the metal layer 25 and polypropylene (PP). The sealing layer 24 is heat-sealed. Since the adhesive strength between aluminum and PP is generally weaker than the adhesive strength between PP and PP, the adhesive strength by thermal fusion at the portion where the gas release mechanism 50 is arranged is equal to the thermal strength at other portions. It can be weaker than the adhesive strength by wearing.

  It should be noted that although the portions where the electrode terminals 41 and 42 protrude are heat-sealed between the aluminum and PP, the adhesive strength of this portion can be adjusted by subjecting the electrode terminals 41 and 42 to surface treatment or heat fusion as described above. The adhesive strength between PP and PP in other portions is made higher by changing the method and conditions of wearing. Therefore, in this case, the portion from which the electrode terminals 41 and 42 protrude does not become the gas release mechanism 50.

  In the laminated battery 14 according to the fourth embodiment, as shown in FIG. 4B, the outer peripheral edge 23 of the laminated films 21 and 22 includes a heat-sealing seal layer 24, and gas is released. The seal layer 24 at the site where the mechanism 50 is disposed is formed from a different material that makes the adhesive strength weaker than the heat-bonding at other sites.

  In the illustrated example, the parts constituting the gas release mechanism 50 include a seal layer 55 made of polyethylene (PE) attached to a part of the seal layer 24 of the upper laminate film 21 that has been partially cut, and a lower laminate film 22. The sealing layer 24 made of polypropylene (PP) is heat-sealed. Since the adhesive strength between PE and PP is generally weaker than the adhesive strength between PP and PP, the adhesive strength by heat fusion at the portion where the gas release mechanism 50 is disposed is equal to the heat strength at other portions. It can be weaker than the adhesive strength by wearing.

  In the laminated exterior battery 15 of the fifth embodiment, as shown in FIG. 4C, the outer peripheral edge 23 of the laminate films 21 and 22 includes a heat-sealing seal layer 24, and gas is released. An adjustment member 56 is interposed between the sealing layers 24 at the portion where the mechanism 50 is disposed to make it weaker than the adhesive strength by heat fusion at other portions. The adjustment member 56 is made of a metal material such as aluminum or nickel, or a resin material such as PP or PE, and has a plate shape.

  In the example shown in the drawing, the adjustment member 56 made of aluminum and the sealing layer 24 made of polypropylene (PP) are heat-sealed at a portion constituting the gas release mechanism 50. As described above, since the adhesive strength between aluminum and PP is weaker than the adhesive strength between PP and PP, the adhesive strength by heat fusion at the portion where the gas release mechanism 50 is disposed is set to the heat strength at other portions. It can be made weaker than the adhesive strength by fusion. For the reasons described above, the portion from which the electrode terminals 41 and 42 protrude does not become the gas release mechanism 50.

  The adjustment member 56 can also be formed from a resin material different from the resin material forming the seal layer 24. For example, when the seal layer 24 is formed from polypropylene (PP), the adjustment member 56 is formed from a heat-fusible film of polyethylene (PE). As described above, since the adhesive strength between PE and PP is weaker than the adhesive strength between PP and PP, the adhesive strength by heat fusion at the portion where the gas release mechanism 50 is disposed is set to the heat strength at other portions. It can be made weaker than the adhesive strength by fusion.

  In the third to fifth embodiments, when the gas pressure in the battery reaches a predetermined pressure (for example, about 1 kgf / cm 2) at the time of abnormality, it is set to be weaker than the adhesive strength due to heat fusion at other parts. The portion of the gas release mechanism 50 thus made cleaves the heat-sealed state and releases the gas to the outside. This prevents a situation such as a rupture of the laminate-cased batteries 13, 14, 15, and improves the reliability at the time of abnormality.

  As in the first embodiment, since the gas release mechanism 50 is disposed in the seal portion 23, even if pressure is applied to the power generation element 31, the gas release mechanism 50 can sufficiently exert the function of releasing gas to the outside in the event of an abnormality. It is possible to prevent the battery performance from being lowered by keeping the distance between the electrodes uniform. Further, since the gas release mechanism 50 is disposed in the seal portion 23, the direction in which the gas is released in the event of an abnormality can be easily set in advance.

  Furthermore, since the gas at the time of abnormality is discharged from the gas release mechanism 50 provided in a part of the seal portion 23, the gas discharge position at the time of abnormality can be set more accurately and easily.

  As described above, the laminated exterior batteries 13 to 14 and 15 of the third to fifth embodiments have the same battery performance as in the first and second embodiments by keeping the distance between the electrodes uniform. The reliability at the time of abnormality can be improved while preventing the decrease, and the direction in which gas is released at the time of abnormality can be easily set in advance.

  In addition, since the gas release mechanism 50 is provided on a part of at least one side of the outer peripheral edge portion 23 of the laminate films 21 and 22 that are heat-sealed, the gas release position at the time of abnormality can be more accurately and easily determined. Can be set to

  In addition, the gas release mechanism 50 is configured by making the adhesive strength by thermal fusion weaker than the adhesive strength by thermal fusion at other parts, so that the function of releasing the gas to the outside in the event of an abnormality is ensured. Can be demonstrated. Such a gas release mechanism 50 can be made weaker than the adhesive strength by heat fusion at other parts by partially cutting off the seal layer 24 at the part where the gas release mechanism 50 is disposed (third implementation). (FIG. 4 (A)), the seal layer 24 at the part where the gas release mechanism 50 is disposed is formed from a different material that makes the adhesive strength weaker than the heat-bonding at the other part (fourth implementation). 4B), an adjustment member 56 for interfering with the adhesive strength by heat fusion at the other part is interposed between the seal layers 24 at the part where the gas release mechanism 50 is disposed. (5th Embodiment, FIG.4 (C)), it can form easily. Since the adjustment member 56 is made of a metal material or a resin material and has a plate shape, the adjustment member 56 can be easily formed.

(Sixth embodiment)
5A to 5C are a front view, a top view, and a side view, respectively, showing a battery module 60 according to a sixth embodiment of the present invention.

  In the sixth embodiment, a plurality of laminated exterior batteries 11 to 15 described in the first to fifth embodiments are electrically connected in parallel and / or in series and stored in the battery storage case 61. Thus, the battery module 60 is configured. Hereinafter, the battery storage case 61 is also simply referred to as “case 61”.

  Specifically, as shown in FIG. 5, for example, four laminated exterior batteries 11 of the first embodiment are connected in parallel (see FIG. 5C), and four groups of four batteries are arranged in parallel. The battery module 60 can be obtained by storing in series in a metal case 61 (see FIGS. 5A and 5B). Thus, the battery module 60 which can respond | correspond to a desired electric current, voltage, and capacity | capacitance can be provided by connecting the arbitrary numbers of the lamination | stacking exterior batteries 11 in series parallel. The case 61 is air-cooled, and cooling air passes around the case 61 when the battery module 60 is used.

  A positive terminal 63 and a negative terminal 64 of the battery module 60 are provided on the upper surface of the case 61. The positive electrode terminal 63 is electrically connected to the positive electrode terminal 41 of the leftmost battery group in the drawing via a lead wire 65. The negative electrode terminal 64 is electrically connected to the negative electrode terminal 42 of the rightmost battery group in the drawing via a lead wire 66. Further, when connecting the four laminated outer batteries 11 in parallel, the electrode terminals 41 and 42 of the respective laminated outer batteries 11 may be electrically connected using an appropriate connecting member such as a spacer 67 ( (See FIG. 5C). Similarly, when four battery groups are connected in series, the electrode terminals 41 and 42 may be electrically connected sequentially using an appropriate connection member such as a bus bar 68 (see FIG. 5A). .

  Each laminated battery 11 is housed so that the power generation element 31 is pressed by the front surface 71 a and the back surface 72 a of the case 61. The upper space and the lower space in the case 61 are filled with an insulating potting material, for example, a urethane-based low temperature thermosetting potting material. By filling the potting material and insulatingly sealing and fixing the connection circuit, the backlash of each laminated battery 11 can be suppressed, the electrode terminals 41 and 42 themselves can be damaged, or the electric power using the spacer 67 and the bus bar 68 can be used. Disconnection of a typical connection circuit is prevented.

  A minute gap space S is formed between the battery groups adjacent in the width direction. In the present embodiment, the gap space S is used for the passage 78 of the gas released from the gas release mechanism 50 at the time of abnormality. As indicated by a circle using a broken line, a cleavage valve 75 is provided on the front surface 71 a of the case 61 at a position communicating with the gas passage 78. When the cleavage valve 75 is provided on the upper surface and / or the lower surface, the filled potting material becomes a ventilation resistance, so that the pressure of the gas released at the time of abnormality does not immediately act on the cleavage valve 75, and the cleavage valve 75. Is unable to perform its function sufficiently and quickly. Therefore, it is preferable to connect the cleavage valve 75 to the gas passage 78 as in this embodiment.

  The cleavage valve 75 includes, for example, a gas discharge hole opened in the front surface 71a and / or the back surface 72a, and a sealing plate that seals the gas discharge hole and opens the gas discharge hole when the internal pressure of the case reaches a predetermined pressure. And have. The sealing plate is formed of an appropriate material such as a sealing material, a metal material, or a resin material, and is attached by a bonding means such as an adhesive or heat fusion so as to seal the gas discharge hole. When the gas released from the laminated outer battery 11 into the case at the time of abnormality reaches a predetermined pressure, the sealing plate is cleaved or ruptured, and the gas filled in the case is released to the outside from the gas discharge hole. Thereby, abnormal expansion | swelling, damage, etc. of case 61 are prevented. The predetermined pressure at which the cleavage valve 75 is actuated can be set as appropriate by changing the material and thickness of the sealing plate, the type of adhesive used, the heat-sealing conditions, and the like. The pressure is the same as the pressure at which 23 is cleaved, for example, about 1 kgf / cm 2.

  In the laminate-cased battery 11 of the present invention, as described above, since the gas release mechanism 50 is disposed in the heat-sealed portions of the laminate films 21 and 22, the direction in which gas is released from the laminate-cased battery 11 at the time of abnormality is set. Can be easily set in advance. Therefore, in the illustrated battery module 60, each laminated battery 11 is housed in a state in which the gas discharge direction is directed to the gas passage 78. According to such a battery module 60, the gas released from the gas release mechanism 50 at the time of abnormality reaches the cleavage valve 75 immediately through the gas passage 78, so that the function of the cleavage valve 75 can be exhibited sufficiently and quickly. It is possible to reliably prevent the case 61 from being damaged.

  As described above, when the battery module 60 is configured, the position where the case cleavage valve 75 is provided can be easily set, and the design of the case 61 and the cleavage valve 75 is facilitated. This is one of the advantages of 11-15.

  The battery module 60 should not be limited to the one described in the embodiment, and a conventionally known one can be appropriately employed. The battery module 60 is provided with various measurement devices and control devices, for example, a voltage measurement connector 69 (indicated by a two-dot chain line in FIG. 5B) for monitoring the battery voltage, depending on the intended use. May be. Furthermore, in order to connect the laminate-clad batteries 11, they may be connected by ultrasonic welding, heat welding, laser welding or electron beam welding, using rivets, or using a caulking method.

  As described above, the laminated exterior batteries 11 to 15 described in the first to fifth embodiments are electrically connected in parallel and / or in series and housed in the case 61 so that the battery module 60 is accommodated. When configured, a battery module 60 having a high capacity and a high output can be formed. In addition, since the direction in which gas is released from the laminate-cased battery 11 at the time of abnormality can be easily set in advance, the position where the cleavage valve 75 for the case 61 is provided when the battery module 60 is configured is easily set. This can facilitate the design of the case 61 and the cleavage valve 75.

(Seventh embodiment)
FIG. 6 is a perspective view showing an assembled battery 90 according to the seventh embodiment of the present invention, and FIG. 7 is a diagram schematically showing the vehicle 100 on which the assembled battery 90 is mounted.

  In the seventh embodiment, a battery pack 60 is configured by electrically connecting a plurality of battery modules 60 described in the sixth embodiment in parallel and / or in series. By using the assembled battery 90, it becomes possible to respond to requests for battery capacity and output for each purpose of use relatively inexpensively without creating a dedicated battery module 60 anew.

  Specifically, as shown in FIG. 6, in order to connect six battery modules 60 in parallel to form an assembled battery 90, the positive terminal 63 and the negative terminal 64 of each battery module 60 are connected to an external positive terminal section. 91a, a positive terminal connecting plate 91 having an external negative terminal portion 92a, and a negative terminal connecting plate 92 are used for electrical connection. Further, a connecting plate 93 having an opening corresponding to the screw hole is fixed to each screw hole (not shown) provided on both side surfaces of each case 61 with a fixing screw 94, and each battery module 60 is connected to each other. Are connected. The positive electrode terminal 63 and the negative electrode terminal 64 of each battery module 60 are protected by positive and negative electrode insulating covers 95 and 96, respectively, and are identified by color-coding appropriate colors, for example, red and blue. A gap for allowing cooling air to pass is provided between the upper battery module 60 and the lower battery module 60.

  As described above, the assembled battery 90 formed by connecting a plurality of battery modules 60 in series and parallel can be repaired only by replacing the failed portion even if some of the batteries 11 or the battery modules 60 fail.

  In order to mount the assembled battery 90 on an electric vehicle (EV), the battery pack 90 is mounted under the seat at the center of the vehicle body of the electric vehicle 100 as shown in FIG. This is because if it is installed under the seat, the interior space and the trunk room can be widened. The place where the battery is mounted is not limited to the position under the seat but may be the lower part of the rear trunk room. If the vehicle is not equipped with an engine such as an EV or FCV (fuel cell vehicle), it can be installed in front of the vehicle on which the engine is generally installed.

  Furthermore, since the laminate-clad battery 11 is lighter than a battery using a metal outer can, the travel distance of an EV vehicle or the like can be improved by reducing the weight of the assembled battery 90 and thus the overall weight of the vehicle 100. Can contribute.

  In the present invention, not only the assembled battery 90 but also a battery module 60, a combination of the assembled battery 90 and the battery module 60, a combination of the battery module 60, or the like depending on the intended use. One laminated outer battery 11 to 15 may be mounted as a single battery. Moreover, as the vehicle 100 on which the laminated exterior batteries 11 to 15, the battery module 60, or the assembled battery 90 of the present invention can be mounted, EV, FCV, and hybrid car (HEV) are preferable, but not limited thereto. Absent.

  As described above, when the assembled battery 90 is configured by electrically connecting a plurality of the battery modules 60 described in the sixth embodiment in parallel and / or in series, the assembled battery 90 is a basic battery. The assembled battery 90 with various capacities and voltages can be obtained simply by changing the number of modules 60 and the connection method.

  Further, by mounting the laminated exterior batteries 11 to 15 described in the first to fifth embodiments, the battery module 60 described in the sixth embodiment, or the assembled battery 90 described in the seventh embodiment, the vehicle It is possible to provide the vehicle 100 that is excellent in fuel consumption and running performance because the weight of the vehicle 100 is not extremely increased and the effective space of the vehicle 100 is not extremely narrowed.

(Other variations)
In the laminate-clad batteries 11 to 15 described in the first to fifth embodiments, the gas release mechanism 50 has one side of the outer peripheral edge portion 23 of the laminate films 21 and 22 that are heat-sealed (FIG. 2). In (A), one location is provided on the right side 23b), but the present invention is not limited to this case. For example, the gas release mechanism 50 may be provided at a plurality of locations on one side or at a plurality of sides. In addition, although the embodiment in which the gas release mechanism 50 is disposed on the sides 23b and 23d other than the side from which the electrode terminals 41 and 42 protrude is illustrated, the gas release mechanism 50 is provided on the sides 23a and 23c from which the electrode terminals 41 and 42 protrude. You may arrange. Further, the gas release mechanism 50 may be formed over the entire at least one side of the outer peripheral edge portion 23 of the laminated films 21 and 22 which are heat-sealed. Even in such a laminated outer battery, even if pressure is applied to the power generation element 31, it can sufficiently exert the function of releasing the gas to the outside at the time of abnormality, and the direction in which the gas is released at the time of abnormality is determined in advance. There is an effect that it can be easily set.

  Although the example which seals the electric power generation element 31 with a pair of laminate films 21 and 22 was given, it is good also as a form which seals the electric power generation element 31 using a bag-shaped laminate film. When the long laminate film is folded in two to form a bag shape, the gas release mechanism 50 may be disposed in the heat-sealed portion of the remaining three sides other than the folded side.

  In the battery module 60 described in the sixth embodiment, a plurality of laminated external batteries 11 are accommodated in the case 61. Of course, one laminated external battery 11 is accommodated in the case. A battery module is also possible.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a use for protecting a laminated battery by providing a mechanism for releasing a gas generated at the time of abnormality.

FIG. 1A is a perspective view showing a laminated outer battery according to the first embodiment of the present invention, and FIG. 1B is a perspective view showing another embodiment of the laminated outer battery. 2 (A) is a plan view showing the laminated battery, FIGS. 2 (B) and 2 (C) are cross-sectional views taken along line 2B-2B of FIG. 2 (A), and cross sections taken along line 2C-2C, respectively. FIG. It is a top view which shows the lamination exterior battery which concerns on the 2nd Embodiment of this invention. 4 (A) to 4 (C) are cross-sectional views showing a part of a gas release mechanism in the laminated exterior battery according to the third to fifth embodiments of the present invention. 5A to 5C are a front view, a top view, and a side view, respectively, showing a battery module according to a sixth embodiment of the present invention. It is a perspective view which shows the assembled battery which concerns on the 7th Embodiment of this invention. It is a figure which represents typically the vehicle by which an assembled battery is mounted.

Explanation of symbols

11-15 laminated battery,
21, 22 Laminated film,
23 outer periphery,
23a-23d Side 24 of outer peripheral edge 24 Seal layer,
25 metal layers,
31 power generation elements,
41, 42 electrode terminals,
50 gas release mechanism,
51 Narrow part,
52 Introduction,
53 Vulnerable part,
54 gap,
55 sealing layer,
56 adjustment members,
60 battery module,
61 Battery storage case,
75 Cleavage valve 78 Gas passageway,
90 battery packs,
100 vehicles,
S Clearance space.

Claims (13)

A laminate film having flexibility;
A power generation element sealed by heat-sealing the outer peripheral edge of the laminate film;
A gas that is disposed in the heat-sealed portion of the laminate film and that releases the gas to the outside by cleaving the heat-sealed state of the outer peripheral edge when the gas generated in the battery reaches a predetermined pressure A laminated outer battery having a discharge mechanism;   2. The laminated exterior battery according to claim 1, wherein the gas release mechanism is provided on a part of at least one side of an outer peripheral edge portion of the laminated film which is heat-sealed.   3. The laminate according to claim 2, wherein the gas release mechanism is provided on a part of one side where the electrode terminal is not disposed at the outer peripheral edge portion of the laminate film which is heat-sealed. Exterior battery.   The gas release mechanism is configured by forming a shape of a portion of the laminate film to be heat-sealed into a shape in which stress due to gas generated in the battery is concentrated. The laminated battery according to the description.   3. The laminated exterior battery according to claim 2, wherein the gas release mechanism is configured by making an adhesive strength by thermal fusion weaker than an adhesive strength by thermal fusion at another portion. The outer peripheral edge of the laminate film includes a heat-sealing seal layer,
6. The laminate-clad battery according to claim 5, wherein a part of the seal layer at a site where the gas release mechanism is disposed is cut away to make it weaker than an adhesive strength by heat fusion at another site. The outer peripheral edge of the laminate film includes a heat-sealing seal layer,
6. The laminate-clad battery according to claim 5, wherein the sealing layer at the portion where the gas release mechanism is disposed is formed of a different material that weakens the adhesive strength by heat fusion at another portion. The outer peripheral edge of the laminate film includes a heat-sealing seal layer,
The adjustment member for making it weaker than the adhesive strength by the heat sealing | fusion in another site | part is interposed between the sealing layers in the site | part which arrange | positions the said gas discharge | release mechanism, The Claim 5 characterized by the above-mentioned. Laminated outer battery.   The laminated exterior battery according to claim 8, wherein the adjustment member is made of a metal material or a resin material and has a plate shape.   2. The laminated battery according to claim 1, wherein the gas release mechanism is formed over at least one side of an outer peripheral edge portion of the laminated film which is heat-sealed.   A battery module comprising: a plurality of laminated exterior batteries according to claim 1 electrically connected in parallel and / or in series and housed in a battery housing case.   An assembled battery comprising a plurality of battery modules according to claim 11 electrically connected in parallel and / or in series.   A vehicle comprising the laminated exterior battery according to claim 1, the battery module according to claim 11, or the assembled battery according to claim 12.

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