JP7075580B2 - Laminated battery module - Google Patents

Description

The present invention relates to a laminated battery module in which a plurality of laminated battery cells are laminated in the stacking direction and electrically connected to each other.

As one form of a battery, there is a laminated battery cell in which a power generation element is housed in a laminated exterior member (see Patent Documents 1 to 5). A laminated battery module in which a plurality of laminated battery cells are electrically connected is widely used as a high-output power source for mounting on a vehicle.

For example, Patent Document 1 discloses a laminated battery module in which a plurality of laminated battery cells are arranged on substantially the same plane, and different polar terminals of adjacent laminated battery cells are electrically connected to each other. In Patent Document 1, each of a plurality of laminated batteries is configured such that a power generation element is accommodated between the upper exterior member and the lower exterior member, and the peripheral edge between the upper exterior member and the lower exterior member is sealed. .. Electrode terminals are derived from between the upper exterior member and the lower exterior member. In Patent Document 1, at least one of the upper exterior member and the lower exterior member is elongated toward the electrode terminal, and the elongated portion covers the portion from which the electrode terminal is derived. This prevents the electrode terminals from being exposed to the outside and prevents an external short circuit.

Japanese Unexamined Patent Publication No. 2005-251617 Japanese Patent No. 4595292 Japanese Unexamined Patent Publication No. 2016-178019 JP-A-2017-134961 Japanese Unexamined Patent Publication No. 2010-161044

By the way, usually, when modularizing a laminated battery cell, different polar terminals of adjacent laminated battery cells are joined by welding. However, in the laminated battery module of Patent Document 1, the electrode terminals are completely covered with the laminated film. Therefore, there is a problem that the laminated film becomes an obstacle and the workability at the time of welding is lowered. Therefore, in the laminated battery module, from the viewpoint of improving productivity, for example, improving production cost and work efficiency, there has been a demand for a structure that prevents external short circuits and facilitates welding and joining.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a laminated battery module having excellent productivity while preventing an external short circuit.

INDUSTRIAL APPLICABILITY According to the present invention, a laminated battery module in which a plurality of laminated battery cells are laminated in the stacking direction and electrically connected to each other is provided. The plurality of laminated battery cells are electrically connected to the laminated outer body, the electrodes and the electrolytes arranged inside the laminated outer body, and the electrodes inside the laminated outer body, respectively, and the laminated outer body is formed. It has an external terminal that protrudes to the outside of the body. The external terminal has a straight portion extending parallel to the laminated surface orthogonal to the stacking direction, and a bent portion connected to the straight portion and bent to one side in the stacking direction. The bent portions are welded together between the laminated battery cells that are electrically connected to each other. The laminated outer body extends longer than the straight portion on the side opposite to the bent direction of the bent portion when viewed from the straight portion.

In the laminated battery module having the above configuration, the laminated exterior body extends to the side opposite to the bent portion when viewed from the straight portion, and the laminated exterior body is interposed between the electrode terminals which are not welded and joined, for example, where insulation is required. There is. This makes it possible to secure insulation between laminated battery cells that are not electrically connected and prevent an external short circuit. At the same time, workability when welding and joining different polar terminals can be ensured, and productivity when modularizing a laminated battery cell can be improved.

It is a side view which shows typically the outer shape of the laminated type battery module which concerns on one Embodiment. It is a partial side view schematically showing the main part of the laminated type battery cell which concerns on one Embodiment. It is a partial side view schematically showing the outer shape of the laminated battery module which concerns on another embodiment.

(First Embodiment)
Hereinafter, preferred embodiments of the laminated battery module disclosed herein will be described with reference to the drawings as appropriate. Matters other than those specifically mentioned in the present specification and necessary for implementation (for example, a general construction process of a laminated battery cell) are designed by those skilled in the art based on the prior art in the art. It can be grasped as a matter. The modules disclosed herein can be implemented on the basis of what is disclosed herein and common general knowledge in the art.

In the present specification, the "laminated battery cell" refers to a general battery having a structure in which a laminated film is used as an exterior body and a power generation element is housed therein. The laminated battery cell may be, for example, a storage battery (secondary battery) such as a lithium ion secondary battery or a nickel hydrogen battery, or may be a storage element such as an electric double layer capacitor.

Further, in the following drawings, members / parts having the same function may be designated by the same reference numerals, and duplicate explanations may be omitted or simplified. The dimensional relationships (length, width, thickness, etc.) in each figure may be deformed for ease of explanation and do not necessarily reflect the actual dimensional relationships. The reference numeral X in the drawings indicates the stacking direction of the laminated battery cells. Further, the reference numeral Y in the drawing is a direction orthogonal to the laminating direction X, and indicates the width direction of the laminated battery cell. Further, the reference numerals U, D, L, and R indicate up, down, left, and right. However, these are merely directions for convenience of explanation, and do not limit the arrangement of the laminated battery cells in any way.

FIG. 1 is a side view schematically showing the outer shape of a laminated battery module (hereinafter, may be simply referred to as a “module”) 1 according to an embodiment. Module 1 includes a plurality of laminated battery cells (hereinafter, may be simply referred to as “battery cells”) 10, 20, and 30. The battery cells 10, 20, and 30 have the same shape. The battery cells 10, 20, and 30 each have a pair of flat surfaces (wide surfaces) 18, 28, and 38, and the wide surfaces 18, 28, and 38 face each other along the stacking direction X. Are lined up. In the present embodiment, the battery cells 10, 20, and 30 are arranged along the stacking direction X without interposing, for example, a heat radiating member, a spacer member, an insulating member, or the like. The even-numbered battery cells from the upper U in the stacking direction X, that is, the battery cells 20, are arranged in a state of being reversed left and right with respect to the odd-numbered battery cells, that is, the battery cells 10 and 30 from the upper U in the stacking direction X. ing. The number of battery cells constituting the module 1 is three here, but the number is not limited to this. The number of battery cells constituting the module 1 may be typically 10 or more, for example, about 10 to 100.

The battery cells 10, 20, and 30 include power generation elements (not shown), positive electrode terminals 12, 22, 32, negative electrode terminals 14, 24, and 34, and laminated exterior bodies 16, 26, 36, respectively. The positive electrode terminals 12, 22, 32 and the negative electrode terminals 14, 24, 34 project to the outer surface of the battery cells 10, 20, 30. The positive electrode terminals 12, 22, 32 and the negative electrode terminals 14, 24, 34 are examples of external terminals. In the present embodiment, the positive electrode terminals 12, 22, 32 and the negative electrode terminals 14, 24, 34 are arranged at the left and right ends of the battery cells 10, 20, and 30. The positive electrode terminal 12 of the battery cell 10 is a positive electrode output terminal that is open so that external connection is possible. Further, the negative electrode terminal 34 of the battery cell 30 is a negative electrode output terminal that is open so that external connection is possible.

The positive electrode terminals 12, 22 and 32 are bent and have straight portions 12b, 22b and 32b, and bent portions 12c, 22c and 32c, respectively. Similarly, the negative electrode terminals 14, 24, and 34 are also bent, and have straight portions 14b, 24b, and 34b, and bent portions 14c, 24c, and 34c, respectively. The straight portions 12b, 22b, 32b, 14b, 24b, and 34b extend parallel to the laminated surface orthogonal to the laminating direction X, here the width direction Y. In other words, it extends parallel to the wide surfaces 18, 28, 38 of the battery cells 10, 20, 30. The bent portions 12c, 22c, 32c, 14c, 24c, and 34c are continuous from the straight portions 12b, 22b, 32b, 14b, 24b, and 34b, and one side (upper U or lower D) of the stacking direction X, specifically, welding. It extends at a substantially right angle toward the side of the different electrode terminal to be joined.

The battery cells 10, 20, and 30 are connected in series. The battery cells 10, 20, and 30 are directly electrically connected without interposing a connecting member such as a bus bar. That is, at the right end portion in the width direction Y, the negative electrode terminal 14 of the battery cell 10 is welded to the positive electrode terminal 22 of the battery cell 20 adjacent to each other in the stacking direction X. Specifically, a welded joint w is provided between the bent portion 14c of the battery cell 10 and the bent portion 22c of the battery cell 20. As a result, the battery cell 10 and the battery cell 20 are electrically connected. Further, at the left end portion in the width direction Y, the negative electrode terminal 24 of the battery cell 20 is welded to the positive electrode terminal 32 of the battery cell 30 adjacent to each other in the stacking direction X. Specifically, a welded joint w is provided between the bent portion 24c of the battery cell 20 and the bent portion 32c of the battery cell 30. As a result, the battery cell 20 and the battery cell 30 are electrically connected.

FIG. 2 is a partial side view schematically showing the vicinity of the negative electrode terminal 14 of the battery cell 10. Hereinafter, the configuration of the battery cell will be described with reference to FIGS. 1 and 2 by taking the battery cell 10 as an example. The battery cell 10 includes a laminated exterior body 16 and a power generation element arranged inside the laminated exterior body 16.

The configuration of the power generation element may be the same as that of a conventionally known battery, and is not particularly limited. The power generation element has, for example, an electrode body and an electrolyte. The electrode body is, for example, a laminated electrode body (laminated electrode body). The laminated electrode body includes one or more rectangular positive electrodes and one or more rectangular negative electrodes, typically a plurality of each. The positive electrode and the negative electrode are alternately stacked in the stacking direction X in an insulated state. The positive electrode and the negative electrode are examples of electrodes. However, the electrode body may be, for example, a wound electrode body (rolled electrode body) in which a strip-shaped positive electrode and a negative electrode are stacked in an insulated state and wound in the longitudinal direction.

The positive electrode contains a positive electrode active material, for example, a lithium transition metal composite oxide such as a lithium nickel cobalt manganese composite oxide. The negative electrode contains a negative electrode active material, for example, a carbon material such as graphite. The positive electrode is electrically connected to the positive electrode terminal 12 inside the laminated exterior body 16. The negative electrode is electrically connected to the negative electrode terminal 14 inside the laminated exterior body 16. The electrolyte may be the same as that of a conventionally known battery cell, and is not particularly limited. The electrolyte may be in the form of a liquid, may be in the form of a polymer (gel), or may be in the form of a solid. The electrolyte may contain, for example, a non-aqueous solvent such as carbonates and esters, and a supporting salt such as a lithium salt that produces a charge carrier.

The laminated exterior body 16 is an insulating container that houses a power generation element. The laminated exterior body 16 is composed of two laminated films 161 and 162. Before the construction of the battery cell 10, the outer shapes of the laminated films 161 and 162 are rectangular in a plan view. The two laminated films 161, 162 are arranged so as to have point symmetry with the center of the electrode body as a point of symmetry. The two laminated films 161, 162 are laminated in a point-symmetrical state, and the peripheral edge portion of the accommodation space accommodating the power generation element is heat-welded to be hermetically sealed. A welded portion s to which the laminated films 161 and 162 are welded is formed on the outer edge portion of the accommodating space. The welded portion s is provided over the entire circumference of the accommodation space, that is, over the four sides of the laminated exterior body 16. The length of the accommodation space in the width direction Y is the same as or longer than the length of the electrode body in the width direction Y.

The laminated film 161 has an extending portion 16a connected to the accommodation space at the right end portion in the width direction Y. The extending portion 16a is a portion extending to the right side in the width direction Y longer than the laminated film 162. The extending portion 16a is arranged parallel to the straight portion 14b of the negative electrode terminal 14 along the surface of the upper U of the straight portion 14b. The extending portion 16a is arranged so as to be flush with the straight portion 14b of the negative electrode terminal 14. The extending portion 16a covers the surface of the upper side U of the straight portion 14b of the negative electrode terminal 14, in other words, the side of the bent portion 14c opposite to the bent direction. The extending portion 16a may or may not be fixed to the straight portion 14b. In the present embodiment, in the width direction Y, the length a of the extending portion 16a is equal to or longer than the length b of the straight portion 14b of the negative electrode terminal 14. That is, the length a of the extending portion 16a and the length b of the straight portion 14b of the negative electrode terminal 14 satisfy a ≧ b. This makes it possible to insulate the upper U surface of the straight portion 14b of the negative electrode terminal 14 and prevent an external short circuit of the straight portion 14b. Further, although not particularly limited, in the present embodiment, the length a of the extending portion 16a, the length b of the straight portion 14b of the negative electrode terminal 14, and the length c of the bent portion 14c of the negative electrode terminal 14 Is (b + c)> a ≧ b.

On the other hand, the laminated film 162 does not extend to the right end portion in the width direction Y. Therefore, the lower D surface of the straight portion 14b, in other words, the surface on the side where the bent portion 14c is provided, is not covered by the laminated film 162. As a result, the lower side D of the straight portion 14b is exposed from the laminated exterior body 16. Therefore, in the present embodiment, when the welded joint portion w is formed between the bent portion 14c of the battery cell 10 and the bent portion 22c of the battery cell 20, the laminated exterior body 16 does not get in the way and is used during welding. Workability is well secured.

As described above, in the battery cells 10, 20 and 30, the side far from the bent portions 12c, 22c, 32c, 14c, 24c and 34c when viewed from the straight portions 12b, 22b, 32b, 14b, 24b and 34b, in other words, Laminated exterior bodies 16, 26, and 36 have a length longer than the straight portions 12b, 22b, 32b, 14b, 24b, and 34b on the side facing the electrode terminals that are not electrically connected. As a result, one side (upper side U or lower side D) of the stacking direction X of the straight portions 12b, 22b, 32b, 14b, 24b, 34b is covered and insulated by the laminated exterior bodies 16, 26, 36. As a result, in the module 1, an external short circuit between the electrode terminals that are not electrically connected is accurately prevented. More specifically, the external short circuit of the battery cells 10 and 20 is prevented at the location (a) in FIG. 1, and the external short circuit of the battery cells 20 and 30 is prevented at the location (b) of FIG.

Further, in the battery cells 10, 20 and 30, the side closer to the bent portions 12c, 22c, 32c, 14c, 24c and 34c when viewed from the straight portions 12b, 22b, 32b, 14b, 24b and 34b, in other words, electrically. The laminated exterior bodies 16, 26, and 36 do not extend to the side facing the connected electrode terminals. As a result, the bent portions 12c, 22c, 32c, 14c, 24c, and 34c are exposed from the laminated exterior bodies 16, 26, and 36. As a result, the positive and negative terminals can be satisfactorily welded and joined, and the productivity of the module 1 can be improved.

The module 1 can be used for various purposes, and can be suitably used, for example, as a power source (driving power source) for a motor mounted on a vehicle. The type of vehicle is not particularly limited, but typically examples thereof include automobiles, for example, plug-in hybrid vehicles (PHVs), hybrid vehicles (HVs), electric vehicles (EVs), and the like.

(Second Embodiment)
In the first embodiment described above, the length a of the extending portion 16a, the length b of the straight portion 14b of the negative electrode terminal 14, and the length c of the bent portion 14c of the negative electrode terminal 14 are (b + c)> a. ≧ b was satisfied, but the present invention is not limited to this.
FIG. 3 is a partial side view schematically showing the outer shape of the module 1A according to another suitable embodiment. Module 1A includes a plurality of battery cells 10A, 20A, 30A. In the battery cells 10A, 20A, and 30A, the length of the extended portion 6a of the laminated exterior body is longer than the total (b + c) of the length b of the straight portion and the length c of the bent portion of the negative electrode terminal described above. In other words, it is the same as the module 1 of the first embodiment described above except that a ≧ (b + c) is satisfied.

In the battery cells 10A, 20A, and 30A, after the negative electrode terminal 14 of the battery cell 10A and the positive electrode terminal 22 of the battery cell 20A are welded and joined, the extension portion 6a is folded to the lower side D of the stacking direction X. Similarly, after the negative electrode terminal 24 of the battery cell 20A and the positive electrode terminal 32 of the battery cell 30A are welded and joined, the extension portion 6a is folded to the lower side D of the stacking direction X. As a result, the welded joint w is surrounded by the extending portion 6a and isolated from the outside. Furthermore, two electrode terminals electrically connected to each other in the module 1A form a set, are surrounded by the extending portion 6a, and are isolated from the outside. As a result, in addition to the above-mentioned effect, that is, the effect of preventing an external short circuit between the electrode terminals that are not electrically connected in the module 1A, the module 1A and other conductive members, for example, second and third. It has the effect of preventing an external short circuit with the modules M2 and M3. More specifically, the external short circuit between the battery cells 10 and 20 and the second module M2 is prevented at the location (c) in FIG. 3, and the battery cells 20 and 30 and the second module M2 are prevented at the location (d) in FIG. External short circuit with module M3 of 3 is prevented. Therefore, in the embodiment in which a ≧ (b + c) is satisfied, the effect of the technique disclosed herein is better exerted.

Although the present invention has been described in detail above, the above-described embodiment is merely an example, and the invention disclosed herein includes various modifications and modifications of the above-mentioned specific examples.

1,1A laminated battery module (module)
10, 20, 30, 10A, 20A, 30A Laminated battery cell (battery cell)
12, 22, 32 Positive electrode terminal (external terminal)
14, 24, 34 Negative electrode terminal (external terminal)
12b, 14b, 22b, 24b, 32b, 34b Straight part 12c, 14c, 22c, 24c, 32c, 34c Bent part 16 Laminate exterior body 161, 162 Laminate film

Claims (1)

A laminated battery module in which a plurality of laminated battery cells are laminated in the stacking direction and electrically connected to each other.
Each of the plurality of laminated battery cells
Laminated exterior and
Electrodes and electrolytes arranged inside the laminated exterior,
External terminals that are electrically connected to the electrodes inside the laminated exterior and project to the outside of the laminated exterior.
Equipped with
The external terminal is
A straight portion extending parallel to the laminated surface orthogonal to the stacking direction,
It has a bent portion that is continuous from the straight portion and bent on one side in the stacking direction.
The laminated battery cells that are electrically connected are welded together with the bent portions exposed from the laminated exterior body .
On the side opposite to the bent direction of the bent portion when viewed from the straight portion, the laminated outer body extends longer than the straight portion with the bent portion exposed .
Laminated battery module.

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