JP2008147089A - Battery module, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery module which can maintain stably electric conduction between electrodes, is superior in insulation between a case and a battery laminate, compact and advantageous in respect of manufacturing workability and cost, and to provide its manufacturing method. <P>SOLUTION: The battery module 1 houses in a case 2 flat batteries B in which a power generation element 13 is sealed inside the outer package 10 of sheet shape and an electrode terminal 15 of plate-shape connected to the power generation element 13 is led outside of the outer package 10. The flat batteries B are laminated a plurality of sheets in thickness direction to form a battery laminate 3 and the electrode terminal 15 of plate-shape protruded from each of battery laminates 3 are jointed to connect electrically the flat batteries in series, and then, an insulating member 29 is inserted between the terminal jointing parts 18. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a battery module in which a battery stack in which a plurality of flat batteries are stacked is housed in a case, and a method for manufacturing the same.

  2. Description of the Related Art In recent years, as power sources for electric vehicles and hybrid vehicles, so-called battery modules are electrically connected in series and / or in parallel to form a high output and high capacity assembled battery.

  In the battery module, a plurality of flat batteries are stacked in the battery thickness direction, and electrode terminals protruding in a direction orthogonal to the stacking direction are electrically connected in series to form a battery stack, and this battery stack Is housed inside the case.

  Since the electrode terminal of each flat battery in such a battery module is usually formed of a thin metal plate, when vibration or the like is applied to the battery module, the terminal joint that joins the electrode terminals in the stacking direction. Since there is a possibility of swinging and coming into contact with each other and short-circuiting, it is necessary to dispose an insulating member between each terminal joint portion.

  For this reason, for example, in Patent Document 1, two electrode terminals are sandwiched by an insulating member, the electrode terminals are joined by sandwiching the electrode terminals, and the terminal joints are insulated by the insulating member. A connection structure is disclosed.

  However, it is difficult to maintain electrical continuity between the electrode terminals only by holding the electrode terminals between the insulating members, and high accuracy is required for the holding surface of the insulating member if it is always necessary to ensure this conductive state. In addition to being disadvantageous in terms of cost, the insulating member may deteriorate with time (deformation with time) and electrical conduction may become unstable.

Further, in consideration of the insulation between terminals and the reliability of electrical continuity as described above, it is conceivable to join the tip of the electrode terminal after sandwiching the electrode terminal with an insulating member as in Patent Document 1. In this case, the length of the electrode terminal protruding in the direction perpendicular to the stacking direction requires a length for adding the insulating member and a dimension for joining, and the length of the battery module It will also lead to an increase in size.
Japanese Patent Laid-Open No. 2004-6141 (Summary, see FIGS. 1 and 3)

  The present invention has been made to solve the problems associated with the prior art, and can stably maintain the electrical continuity between the electrode terminals, and has excellent insulation between the case and the battery stack. An object of the present invention is to provide a battery module that is compact and advantageous in terms of manufacturing workability and cost, and a manufacturing method thereof.

  The battery module manufacturing method according to the present invention is a flat structure in which a power generation element is sealed inside a sheet-shaped exterior body, and a plate-like electrode terminal connected to the power generation element is led out of the exterior body. A battery module manufacturing method in which a battery is housed in a case, wherein a plurality of the flat batteries are stacked in the thickness direction of the flat battery to form a battery stack, and the battery stack The step of joining the electrode terminals adjacent to each other in the stacking direction among the plate-like electrode terminals projecting in a direction orthogonal to the stacking direction from each flat battery, and connecting the flat batteries electrically in series And inserting an insulating member between a plurality of terminal joints formed by joining the electrode terminals.

  The battery module according to the present invention is a flat battery in which a power generation element is sealed inside a sheet-shaped exterior body, and a plate-like electrode terminal connected to the power generation element is led out of the exterior body. A battery module housed in a case, wherein a plurality of the flat batteries are stacked in the thickness direction of the flat battery, and each battery has a direction perpendicular to the stacking direction from each flat battery. An insulating member is inserted between terminal joints joined so as to electrically connect electrode terminals adjacent in the laminating direction among the plate-like electrode terminals protruding in the direction.

  In the present invention, plate-like electrode terminals projecting in a direction orthogonal to the stacking direction are joined from each flat battery of a battery stack formed by stacking a plurality of flat batteries in the thickness direction. Therefore, the electrical continuity between the electrode terminals can always be stably maintained, and it is not necessary to finish the insulating member itself with high accuracy, which is advantageous in terms of cost.

  In particular, since a plurality of terminal joints are formed by joining electrode terminals and then an insulating member is inserted between the terminal joints, the length of the electrode terminals only needs to be joined and separately insulated. The length for installing the member becomes unnecessary, and the battery module itself becomes compact.

  Furthermore, if a plurality of insulating members provided between the terminal joints are integrated, the installation of the insulating members is easy and the workability is improved. And since an insulating member covers a terminal junction part from the outside, the insulation between not only between each terminal junction part but a case and a battery laminated body is also improved.

  Hereinafter, the battery module according to the present invention will be described in detail.

  FIG. 1 is a schematic exploded perspective view showing an example of a battery module, FIG. 2 shows one flat battery, (A) is a schematic plan view of the flat battery, and (B) is a BB line in (A). The principal part expansion schematic sectional drawing in alignment with FIG. 3, FIG. 3 is a principal part schematic sectional drawing of a battery laminated body.

  As shown in FIG. 1, the battery module 1 includes a case 2 made of a relatively thin steel plate or aluminum plate, and a battery stack 3 made up of a plurality of flat batteries B housed in the case 2. is doing.

  The case 2 is composed of a lower case 4 having an upper opening and an upper case 6 that is a lid for closing the opening 5 of the lower case 4. Combined by processing.

  As shown in FIGS. 2 (A) and 2 (B), the flat battery B has two sheet-like exterior bodies 10 made of a laminate film having a three-layer structure in which, for example, both surfaces of an aluminum layer are covered with a resin layer. In addition, the power generation element 13 in which the positive electrode plate 11p and the negative electrode plate 11m and the separator 12 are stacked is sealed, and has a rectangular shape in plan view as a whole.

  One end of a plate-like electrode terminal 15 (positive electrode terminal 15p, negative electrode terminal 15m) is connected to the electrode plates 11p, 11m of the power generation element 13 via a connection line 16, and the other end of each electrode terminal 15 is connected. Is led out of the outer package 10 in a direction orthogonal to the stacking direction of the batteries. Each flat battery B is provided with a voltage detection member 17 and is connected to an external voltage detection device (not shown) so that the voltage can be detected.

  As shown in FIG. 3, a plurality (8 in the illustrated example) of the battery stack 3 are stacked in the thickness direction of the battery so that the positive electrode terminal 15p and the negative electrode terminal 15m of the flat battery B are opposed to each other. Is formed. In the case of the flat battery B illustrated in FIG. 2A, the positive electrode terminal 15p and the negative electrode terminal 15m of the pair of upper and lower flat batteries B are arranged so as to be shifted by 180 degrees so that both the electrode terminals 15 Are electrically connected in series by ultrasonic bonding or welding.

  FIG. 4 is a cross-sectional view of the main part showing an example of the battery module manufacturing method according to the present invention. In this embodiment, as shown in FIG. 4, a terminal bar is formed by joining a bus bar (not shown) together with the electrode terminal 15 comprising the positive electrode terminal 15p and the negative electrode terminal 15m of the battery module 3 or the electrode terminal 15. 18 is formed, and an insulating member 29 corresponding to the spacer 20 is inserted between the terminal joints 18 in which the distance S is relatively large to insulate the terminal joints 18 from each other. Insulating member 29 is preferably made of a synthetic resin such as polypropylene or ABS.

  If the insulating member 29 is inserted after the electrode terminals 15 are joined in this manner and the distance between the terminal joints 18 becomes relatively large, there is no short circuit between the terminal joints 18 even if vibration is applied. The electrical continuity of the battery module 1 is always stable, and the workability is greatly improved.

  FIG. 5 is a schematic perspective view showing Modification 1 of the insulating member. As shown in FIG. 5, the insulating member 29 of this example includes end portions of a plurality of insulating plates 29 a installed between the terminal joint portions 18 (outer side end portions in a direction perpendicular to the stacking direction of the battery stack 3). Further, an end plate 29b is provided so as to be integrated as a whole. In this way, if one of the plurality of insulating plates 29a is positioned at one position between the plurality of terminal joints, the other insulating plate 29a is also positioned between the terminal joints, so that the insulating member 29 Is easy and the workability is improved, and the insulating member 29 also covers the terminal joint 18 from the outside, so that the insulation between the case 6 and the battery stack 3 is also improved.

  FIG. 6 is a schematic perspective view showing Modification Example 2 of the insulating member. In order to further improve the insulation, the terminal joints 18 are insulated from each other and covered from the outside. For example, as shown in FIG. 6, the insulating member 29 includes upper and lower insulating plates 29u and 29w that cover the uppermost terminal joint 18 and the lowermost terminal joint 18, the end plate 29b, and both sides. A side plate 29c to be provided may be provided, and these may be integrated.

  In this way, the installation of the insulating member 29 is completed by inserting the insulating member 29 between the terminal joints 18 projecting in a direction orthogonal to the battery stacking direction from the battery stack 3. The mounting workability is improved, and the insulating member 29 covers the entire terminal joint 18 from the outside, so that the insulating property between the case 6 and the battery stack 3 is further improved.

  FIG. 7 is a schematic perspective view showing Modification 3 of the insulating member. The battery module 1 is used as an assembled battery in which a plurality of battery modules 1 are stacked and connected in a biographical manner in order to obtain a battery having a desired current, voltage, and capacity. In order to configure this assembled battery, FIG. As shown, the case 2 has a bolt hole O1 through which a bolt is inserted. Further, the insulating plate 29 is also provided with a bolt hole O2. These bolt holes O1 and O2 are provided with sleeves 28, through which the bolts are inserted.

  In this case, as shown in FIG. 7, when the sleeve 28 is formed integrally with the insulating member 29, the insulating member 29 is positioned and fixed by inserting a bolt into the sleeve 28, so that the insulating member 29 is positioned. In addition, a complicated structure for fixing is unnecessary.

  In FIG. 1, notches 30, 31, 32 are formed on the short side of the side plate portion 4 a of the lower case 4, and the notch 30 is electrically uppermost among the batteries constituting the battery stack 3. The plus terminal 22p connected to the plus terminal of the upper (highest potential) battery is connected to the notch 31 as the minus terminal of the battery constituting the battery stack 3 in the electrically lowermost (lowest potential) battery. The connected minus terminal 22m is provided, and the notch 32 is provided so as to correspond to the insertion port 27 into which the connector connected to the voltage detection plate 17 is inserted. In FIG. 1, “33” is a cushioning material.

  Next, a method for manufacturing the battery module 1 will be described.

  First, a plurality of (eight in the illustrated example) stacked flat batteries B in the thickness direction of the flat batteries B are stacked to form the battery stack 3.

  And among the plate-like electrode terminals 15 projecting from each flat battery B of the battery stack 3 in a direction orthogonal to the stacking direction, the electrode terminals adjacent in the stacking direction, that is, the positive electrodes adjacent in the vertical direction The electrode terminal 15p and the negative electrode terminal 15m are joined by ultrasonic joining, welding, or the like. Each battery B is electrically connected in series by this joining, and four terminal joining portions 18 protrude from the battery stack 3 in a direction orthogonal to the stacking direction of the batteries B.

  Next, an insulating member 29 is inserted between the terminal joints 18. One insulating member 29 is inserted between each terminal joint 18. As a result, even if vibration or the like is applied to the battery module 1, the terminal joint portions 18 do not come into contact with each other, a short circuit between the batteries B is prevented, and electrical conduction in the battery module 1 is always stable. .

  However, the operation of inserting the insulating members 29 one by one between the respective terminal joints 18 is poor in work efficiency when producing a large amount of the battery module 1, and therefore, as in the insulating member 29 shown in FIG. When a plurality of insulating plates 29a installed between the joints 18 are integrated by the end plates 29b, the plurality of insulating members 29 can be installed at a time, and the work efficiency is improved. Moreover, since the end plate 19b of the insulating member 29 exists between the case 2 and the battery stack 3 when the battery stack 3 is stored in the case 2, the case 6 and the battery stack 3 The insulation between the two is also improved.

  Further, when a box-shaped member such as the insulating member 29 shown in FIG. 6 is used, the terminal joint 18 can be covered from the surroundings, and not only the work efficiency of attaching the insulating member 29 is improved, but also the battery laminate. 3 is housed in the case 2, the end plate 29 b of the insulating member 29 exists between the case 2 and the battery stack 3, so that the insulation between the case 6 and the battery stack 3 is present. Will also improve.

  Furthermore, when the one formed integrally with the sleeve 20 such as the insulating member 29 shown in FIG. 7 is used, the terminal joint 18 is covered from the surroundings, so that the insulation is improved and the insulating member 29 In addition to improving the workability of attachment, the sleeve 20, the spacer 20, the insulating cover 24, and the smoke-saving member 29 can be made into one component, which reduces the number of components and is advantageous in terms of cost.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. For example, in the above-described embodiment, the insulating member 29 covers the entire terminal joint portion 18, but may partially cover the same, and the same applies when used as the insulating cover 24.

  The present invention can be used for manufacturing a battery module, can stabilize electrical continuity between electrode terminals, and can improve assembly workability.

It is a schematic exploded perspective view which shows an example of a battery module. 1 shows one flat battery, (A) is a schematic plan view of the flat battery, and (B) is an enlarged schematic cross-sectional view of a main part along the line BB of (A). It is a principal part schematic sectional drawing of a battery laminated body. It is principal part sectional drawing which shows an example of the battery module manufacturing method which concerns on this invention. It is a schematic perspective view which shows the modification 1 of an insulating member. It is a schematic perspective view which shows the modification 2 of an insulating member. It is a schematic perspective view which shows the modification 3 of an insulating member.

Explanation of symbols

1 ... Battery module,
2 ... Case,
3 ... Battery stack,
10 ... exterior body,
13 ... Power generation element,
15 ... Electrode terminal,
18 ... terminal junction,
24 ... cover member,
29. Insulating member,
29a ... insulating plate,
B: Flat battery.

Claims (6)

A battery in which a power generation element is sealed inside a sheet-like exterior body, and a flat battery formed by leading plate-like electrode terminals connected to the power generation element to the outside of the exterior body is housed inside the case A method of manufacturing a module,
A step of laminating a plurality of the flat batteries in the thickness direction of the flat batteries to form a battery laminate;
Of the plate-like electrode terminals projecting in a direction perpendicular to the stacking direction from the flat batteries of the battery stack, the electrode terminals adjacent in the stacking direction are joined together to electrically connect the flat battery. Connecting in series;
Inserting an insulating member between a plurality of terminal joints formed by joining the electrode terminals;
The manufacturing method of the battery module which has this.   The method of manufacturing a battery module according to claim 1, wherein the step of inserting the insulating member inserts the insulating member in which an insulating plate to be inserted between the plurality of terminal joints is integrated. A battery in which a power generation element is sealed inside a sheet-like exterior body, and a flat battery formed by leading plate-like electrode terminals connected to the power generation element to the outside of the exterior body is housed inside the case A module,
Of the plate-like electrode terminals protruding in a direction orthogonal to the stacking direction from each flat battery of a battery stack formed by stacking a plurality of the flat batteries in the thickness direction of the flat battery, A battery module, wherein an insulating member is inserted between terminal joints joined so that electrode terminals adjacent in the stacking direction are electrically connected in series.   The battery module according to claim 3, wherein the insulating member is an integrated insulating plate inserted between the plurality of terminal joints.   The battery module according to claim 4, wherein the insulating member is configured to entirely cover the terminal joint portion from the outside.   The battery module according to any one of claims 3 to 5, wherein the insulating member is integrally provided with a cover member that covers at least a part of the plurality of terminal joints.

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