Laminated battery

Abstract

A laminated battery is provided with: an electrode body; a side surface member disposed on a side surface of the electrode body; and a laminated film covering the electrode body and a part of the side surface member, the side surface member being disposed at a position offset from a center of the side surface in a longitudinal direction of the side surface, the side surface member being offset from the center in the longitudinal direction of the side surface being an offset side, and the other side being a non-offset side. Among the side surface members, the volume of the side surface member located on the deflection side is equal to the volume of the side surface member located on the non-deflection side.

Description

Technical Field

[0001] The present disclosure relates to a laminated battery. Background Art

[0002] Conventionally, a laminated battery is used which includes an electrode body, side members such as a terminal, and a laminate film covering a portion of the electrode body and the side members.

[0003] For example, Japanese Patent Application Laid-Open No. 11-283611 discloses a battery in which a terminal on one side is arranged offset to one side with respect to the center of the side. Summary of the invention

[0004] Conventionally, a laminated battery is used which includes an electrode body, side members such as terminals, and a laminate film covering the electrode body and a portion of the side members. In such a laminated battery, the side member is sometimes disposed at a position offset to one side relative to the center of the side in the longitudinal direction of the side.

[0005] However, in an electrode body in which a side member is disposed biased on one side, a difference in resistance may occur between one side (biased side) and the other side (non-biased side) where the side member is biased, with the center of the side being the boundary.

[0006] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a laminated battery in which a difference in resistance between one side and the other side is suppressed with the center of the side surface as a boundary.

[0007] Means for solving the above-mentioned problems include the following.

[0008] <1> A laminated battery, comprising:

[0009] Electrode body;

[0010] A side member disposed on a side of the electrode body; and

[0011] a laminate film covering the electrode body and a portion of the side member,

[0012] The side member is arranged at a position offset to one side relative to the center of the side in the length direction of the side.

[0013] When one side of the side member that is biased relative to the center in the length direction of the side is set as the biased side and the other side is set as the non-biased side, the volume of the side member located on the biased side of the side is equal to the volume of the side member located on the non-biased side.

[0014] <2> according to <1> In the laminated battery, the side member has a shape in which the thickness becomes thinner continuously from the non-biased side toward the biased side.

[0015] <3> according to <1> In the laminated battery, the side member has a hole formed in a region on the biased side with the center of the side surface as the boundary.

[0016] According to the present disclosure, it is possible to provide a laminated battery in which the difference in resistance between one side and the other side is suppressed with the center of the side surface as the boundary. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals represent like elements, and wherein:

[0018] Figure 1 It is a schematic perspective view showing an electrode body and a side member in a laminated battery according to an embodiment of the present disclosure.

[0019] Figure 2A Observed from the side Figure 1 A schematic side view of a laminated battery is shown.

[0020] Figure 2B This is a schematic side view of a laminated battery according to another mode of the embodiment of the present disclosure as viewed from the side.

[0021] Figure 3 It is a schematic plan view showing the main parts of a vehicle.

[0022] Figure 4 This is a schematic perspective view of a battery module.

[0023] Figure 5 This is a plan view of the battery module with the upper cover removed.

[0024] Figure 6 This is a schematic diagram of a battery cell housed in a battery module as viewed from the thickness direction. DETAILED DESCRIPTION

[0025] An embodiment as an example of the present disclosure will be described. These descriptions illustrate the embodiment and do not limit the scope of the invention.

[0026] <Laminated battery>

[0027] The laminated battery according to the embodiment of the present disclosure includes an electrode body, a side member arranged on a side of the electrode body, and a laminate film covering the electrode body and a portion of the side member, wherein the side member is arranged at a position offset to one side relative to the center of the side in the longitudinal direction of the side.

[0028] Furthermore, when one side member located biased relative to the center in the longitudinal direction of the side is defined as the biased side and the other side is defined as the non-biased side, the volume of the side member located on the biased side is equal to the volume of the side member located on the non-biased side.

[0029] When the side member is arranged at a position that is biased to one side relative to the center of the side in the longitudinal direction of the side (i.e., a position that is deviated from the center of the side), the volume of the side member becomes relatively larger on the side (biased side) to which the side member is biased, and the volume of the side member becomes relatively smaller on the other side (non-biased side) with the center of the side as the boundary. Therefore, the biased side where the volume of the side member is relatively larger becomes low resistance, while the non-biased side where the volume of the side member is relatively smaller becomes high resistance, that is, a difference in resistance occurs between the biased side and the non-biased side in the side.

[0030] In contrast, in the laminated battery of the embodiment of the present disclosure, the volume of the biased side of the side member is equal to the volume of the non-biased side, with the center of the side as the boundary. Therefore, the resistance of one of the biased side and the non-biased side of the side can be suppressed from increasing, and the resistance difference between the biased side and the non-biased side of the side can be suppressed.

[0031] Hereinafter, a laminated battery according to an embodiment of the present disclosure will be specifically described with reference to the drawings as examples.

[0032] Each of the drawings shown below is schematically shown, and the size and shape of each part are appropriately exaggerated to make it easier to understand.

[0033] ·First method

[0034] Figure 1 It is a schematic perspective view showing an electrode body and a side member of a laminated battery according to a first aspect of an embodiment of the present disclosure. Figure 2A is from Figure 1 The side direction of the laminated battery shown (the direction of the surface where the side member is arranged, Figure 1 and Figure 2A , Figure 2B A schematic side view of the device as viewed in the Z direction.

[0035] like Figure 1 As shown, the electrode body 4 in the laminated battery of the first embodiment has terminals 26 as an example of side members, which are respectively arranged on a pair of side surfaces 4A thereof. In addition, in the side surface 4A of the electrode body 4, there are two areas 41A and 42A where the terminals 26 are not arranged on both sides of the side surface 4A in the longitudinal direction (arrow X direction) of the side surface 4A.

[0036] The terminal 26 is arranged at a position offset to one side with respect to the center Lc1 of the side surface 4A in the longitudinal direction (the direction of the arrow X) of the side surface 4A of the electrode body 4 ( Figure 1 and Figure 2A In the present disclosure, in the longitudinal direction of the side surface 4A (the direction of the arrow X), one side where the terminal 26 is located offset relative to the center Lc1 is referred to as the “offset side”, and the other side is referred to as the “non-offset side”.

[0037] In the side surface 4A of the electrode body 4, the area of ​​the region 42A where the terminal 26 is not arranged on the side (the deflected side) where the terminal 26 is arranged biasedly is smaller than the area of ​​the other side (the non-deflected side), and the area of ​​the region 41A on the non-deflected side is larger than the area of ​​the region 42A on the deflected side. In addition, hereinafter, the larger area of ​​the two areas where the side member is not arranged on the side of the electrode body is referred to as a "wide area", and the smaller area is referred to as a "narrow area".

[0038] In the laminated battery of the first embodiment, Figure 2A As shown, the laminate film 28 is arranged to cover the electrode body 4 and a portion of the terminal 26. The laminate film 28 is arranged to cover the entire surface of the electrode body 4, and the area where the terminal 26 is not provided in the side surface 4A of the electrode body 4 is completely covered by the laminate film 28 (therefore, Figure 2A The electrode body 4 covered by the laminate film 28 is shown by a dotted line. In addition, the laminate film 28 is configured to cover a portion of each of the upper surface 26B, one side 26C, the lower surface 26D, and the other side 26E of the terminal 26, and more specifically, to cover the regions on the four sides of the electrode body on these four surfaces. Therefore, the entire surface of the outer side surface 26a of the terminal 26 and the regions on the side opposite to the electrode body 4 of the upper surface 26B, one side 26C, the lower surface 26D, and the other side 26E are not covered by the laminate film 28 and are exposed.

[0039] In addition, the terminal 26 has a shape in which the thickness continuously decreases toward the side where the terminal 26 is disposed biasedly, that is, the thickness continuously decreases from the non-biased side to the biased side. In other words, in the two regions 41A and 42A where the terminal 26 is not disposed in the side surface 4A of the electrode body 4, the thickness of the terminal 26 continuously decreases from the side of the large area (wide area) 41A to the side of the small area (narrow area) 42A. In addition, the thickness of the terminal 26 refers to Figure 1 and Figure 2A With this structure, the terminal 26 has a structure in which the volume of the non-deflected side region 261 and the volume of the deflected side region 262 are equal, with the center Lc1 of the side surface 4A as a boundary.

[0040] As mentioned above, Figure 1 and Figure 2AThe laminated battery shown has a structure in which the volume of the side member on the deflected side and the volume of the non-deflected side are equal with respect to the center of the side surface, and the resistance difference between the deflected side and the non-deflected side of the side surface can be suppressed.

[0041] In addition, Figure 1 and Figure 2A In the embodiment, the terminal 26 has a shape in which the thickness continuously decreases from the non-deflected side toward the deflected side. However, the present invention is not limited to this embodiment, and for example, the side member may have a shape in which the thickness gradually decreases from the non-deflected side toward the deflected side.

[0042] Second method

[0043] Figure 2B The laminated battery of the second embodiment of the present disclosure is viewed from the side direction (the direction of the surface where the side member is arranged, Figure 2A , Figure 2B A schematic side view of the device as viewed in the Z direction.

[0044] In addition, in the laminated battery of the second embodiment, the structure other than the terminal as an example of the side member is the same as that of the laminated battery of the first embodiment, and therefore the detailed description is omitted here.

[0045] like Figure 2B As shown, the electrode body 4 in the laminated battery of the second embodiment has terminals 27 as an example of side members, which are respectively arranged on a pair of side surfaces 4A thereof. In addition, in the side surface 4A of the electrode body 4, in the longitudinal direction (arrow X direction) of the side surface 4A, there are two areas 41A and 42A on both sides of the terminal 27 where the terminal 27 is not arranged.

[0046] The terminal 27 is arranged at a position offset to one side with respect to the center Lc1 of the side surface 4A in the longitudinal direction (the direction of the arrow X) of the side surface 4A of the electrode body 4 ( Figure 2B In the present disclosure, in the longitudinal direction of the side surface 4A (the direction of the arrow X), one side where the terminal 27 is located offset relative to the center Lc1 is referred to as the “offset side”, and the other side is referred to as the “non-offset side”.

[0047] In side surface 4A of electrode body 4 , area of ​​region 42A where terminals 27 are not arranged on one side (the deviated side) where terminals 27 are deviated is smaller than that on the other side (the non-deviated side), and area of ​​region 41A on the non-deviated side is larger than that of region 42A on the deviated side.

[0048] In addition, the terminal 27 has five holes 270 formed in the area 272 on the deflected side with the center Lc1 of the side 4A as the boundary. Since the hole 270 is hollow, the area of ​​the hole 270 is not included in the volume of the terminal 27. Since the hole 270 not included in the volume of the terminal 27 is formed in the area 272 on the deflected side of the terminal 27, the volume of the area 272 on the deflected side is reduced in the terminal 27. As a result, the terminal 27 has a structure in which the volume of the area 271 on the non-deflected side and the volume of the area 272 on the deflected side with the center Lc1 of the side 4A as the boundary are equal.

[0049] As mentioned above, Figure 2B The laminated battery shown has a structure in which the volume of the deflected side and the volume of the non-deflected side of the side member are equal with respect to the center of the side surface, and the resistance difference between the deflected side and the non-deflected side of the side surface can be suppressed.

[0050] In addition, Figure 2B In the embodiment, the method of forming five circular holes 270 is described. However, the present invention is not limited to this method, and the shape of the holes and the number of the holes can be freely changed.

[0051] Next, a battery module, a battery pack, and a vehicle having a laminated battery according to an embodiment of the present disclosure are described using the drawings.

[0052] (Overall Structure of Vehicle 100)

[0053] Figure 3 1 is a schematic plan view showing the main parts of a vehicle 100 to which the battery pack 10 according to the embodiment is applied. Figure 3 As shown, the vehicle 100 is an electric vehicle (BEV) equipped with a battery pack 10 under the floor. In addition, the upward arrow, the forward arrow, and the left arrow in each figure respectively indicate the upper side in the vehicle vertical direction, the front side in the vehicle front-back direction, and the left side in the vehicle width direction. When the front-back, left-right, up-down and down directions are used for description, unless otherwise specified, they indicate the front-back in the vehicle front-back direction, the left-right in the vehicle width direction, and the up-down in the vehicle vertical direction.

[0054] As an example, the vehicle 100 of the present embodiment has a DC / DC converter 102, an electric compressor 104, and a PTC (Positive Temperature Coefficient) heater 106 disposed on the vehicle front side relative to the battery pack 10. In addition, a motor 108, a gear box 110, an inverter 112, and a charger 114 are disposed on the vehicle rear side relative to the battery pack 10.

[0055] The DC current output from battery pack 10 is regulated in voltage by DC / DC converter 102 and then supplied to electric compressor 104, PTC heater 106, inverter 112, etc. Furthermore, by supplying electric power to motor 108 via inverter 112, the rear wheels rotate and vehicle 100 travels.

[0056] A charging port 116 is provided on the right side of the rear portion of the vehicle 100 . By connecting a charging plug of an external charging device (not shown) to the charging port 116 , electric power can be stored in the battery pack 10 via the charger 114 .

[0057] In addition, the configuration and structure of each component constituting the vehicle 100 are not limited to the above-mentioned structure. For example, it can also be applied to a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV) equipped with an engine. In addition, in the present embodiment, the motor 108 is mounted on the rear of the vehicle and the vehicle is rear-wheel driven, but it is not limited to this. The motor 108 may be mounted on the front of the vehicle and the vehicle may be a front-wheel drive vehicle, or a pair of motors 108 may be mounted on the front and rear of the vehicle. In addition, it may be a vehicle equipped with an in-wheel motor on each wheel.

[0058] Here, the battery pack 10 is composed of a plurality of battery modules 11. In the present embodiment, as an example, 10 battery modules 11 are provided. Specifically, on the right side of the vehicle 100, five battery modules 11 are arranged in the vehicle front-rear direction, and on the left side of the vehicle 100, five battery modules 11 are arranged in the vehicle front-rear direction. In addition, each battery module 11 is electrically connected.

[0059] Figure 4 1 is a schematic three-dimensional diagram of the battery module 11. Figure 4 As shown, the battery module 11 is formed into a substantially rectangular parallelepiped shape with the vehicle width direction as the length direction. In addition, the outer shell of the battery module 11 is formed of an aluminum alloy. For example, an aluminum die casting is joined to both ends of an extruded material of an aluminum alloy by laser welding or the like, thereby forming the outer shell of the battery module 11.

[0060] A pair of voltage terminals 12 and a connector 14 are provided at both ends of the battery module 11 in the vehicle width direction. A flexible printed circuit board 22 described later is connected to the connector 14. Bus bars (not shown) are welded to both ends of the battery module 11 in the vehicle width direction.

[0061] The battery module 11 has a length MW in the vehicle width direction of, for example, 350 mm to 600 mm, a length ML in the vehicle front-rear direction of, for example, 150 mm to 250 mm, and a height MH in the vehicle vertical direction of, for example, 80 mm to 110 mm.

[0062] Figure 5 1 is a plan view of the battery module 11 with the upper cover removed. Figure 5 As shown, a plurality of battery cells 20 are housed in an aligned state inside the battery module 11. In the present embodiment, as an example, 24 battery cells 20 are aligned in the vehicle front-rear direction and bonded to each other.

[0063] A flexible printed circuit (FPC) 22 is disposed above the battery cell 20. The flexible printed circuit 22 is formed in a strip shape with the vehicle width direction as the longitudinal direction, and thermistors 24 are provided at both ends of the flexible printed circuit 22. The thermistor 24 is not bonded to the battery cell 20 but is pressed toward the battery cell 20 by the upper cover of the battery module 11.

[0064] In addition, one or more buffers (not shown) are accommodated inside the battery module 11. For example, the buffer is a thin plate-shaped member that can be elastically deformed, and is arranged between adjacent battery cells 20 with the arrangement direction of the battery cells 20 as the thickness direction. In this embodiment, as an example, the buffers are respectively arranged at both ends and the center of the battery module 11 in the longitudinal direction.

[0065] Figure 6 2 is a schematic diagram of a battery cell 20 housed in a battery module 11 as viewed from the thickness direction. Figure 6 As shown, the battery cell 20 is formed in a substantially rectangular plate shape, and an electrode body (not shown) is housed therein. The electrode body is formed by stacking a positive electrode, a negative electrode, and a separator, and is sealed by a laminate film 28 .

[0066] In this embodiment, as an example, the electrode body receiving portion is formed by folding and laminating the embossed sheet-shaped laminate film 28. In addition, two structures can be adopted: a single cup embossing structure with one embossing location and a double cup embossing structure with two embossing locations. In this embodiment, the single cup embossing structure with an embossing depth of about 8 mm to 10 mm is adopted.

[0067] The upper ends of both ends of the battery cell 20 in the longitudinal direction are bent, and the corners become the outer shape. In addition, the upper end of the battery cell 20 is bent, and the fixing band 30 is wound around the upper end of the battery cell 20 along the longitudinal direction.

[0068] Here, terminals (tabs) 26 are provided at both ends of the battery cell 20 in the longitudinal direction. In the present embodiment, as an example, the terminals 26 are provided at positions offset downward from the vertical center of the battery cell 20. The terminals 26 are joined to bus bars (not shown) by laser welding or the like.

[0069] The length CW1 of the battery cell 20 in the vehicle width direction is, for example, 530 mm to 600 mm, 600 mm to 700 mm, 700 mm to 800 mm, 800 mm to 900 mm, or 1000 mm or more, the length CW2 of the region accommodating the electrode body is, for example, 500 mm to 520 mm, 600 mm to 700 mm, 700 mm to 800 mm, 800 mm to 900 mm, or 1000 mm or more, and the height CH of the battery cell 20 is, for example, 80 mm to 110 mm, 110 mm to 140 mm. In addition, the thickness of the battery cell 20 is 5.0 mm to 7.0 mm, 7.0 mm to 9.0 mm, 9.0 mm to 11.0 mm, and the height TH of the terminal 26 is 40 mm to 50 mm, 50 mm to 60 mm, or 60 mm to 70 mm.

Claims

1. A laminated battery, wherein: have: Electrode body; A side member disposed on a side of the electrode body; and a laminate film covering the electrode body and a portion of the side member, The side member is arranged at a position offset to one side relative to the center of the side in the length direction of the side. When one side of the side member that is biased relative to the center in the length direction of the side is set as the biased side and the other side is set as the non-biased side, the volume of the side member located on the biased side of the side is equal to the volume of the side member located on the non-biased side.

2. The laminated battery according to claim 1, wherein The side member has a shape in which the thickness continuously becomes thinner from the non-deflected side toward the deflected side.

3. The laminated battery according to claim 1, wherein The side member has a hole formed in a region on the side deviated from the center of the side surface.

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