JP2018037358A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack capable of improving vibration resistance and impact resistance.SOLUTION: Disclosed is a battery pack 700 including a battery coupling structure in which a plurality of battery cells are laminated having a positive electrode lead-out tab 120 and a negative electrode lead-out tab 130 led-out from one side of a rectangular laminate film casing material 103 and neighboring battery cells 100 are electrically connected to each other. Between the positive electrode lead-out tab 120 and the negative electrode lead-out tab 130, inter-tab protection buffer members 314 are arranged in contact with the rectangular laminate film casing materials 103.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a battery pack containing a battery connection structure in which battery cells such as lithium ion secondary batteries are connected.

  Battery packs equipped with primary and secondary batteries are not only small power sources for portable devices such as mobile phones, digital cameras, and laptop computers, but also medium-sized power sources such as simple backup power sources for electric carts and small equipment. It is also widely used as a power source and a large power source for vehicles and homes.

  The battery pack is a container in which a battery such as a primary battery or a secondary battery and a circuit board including a protection circuit are accommodated in a container. As a battery mounted inside a container, a lithium ion battery that is light and has a high energy density is often used. In particular, a laminate battery using a laminate film made of a flexible aluminum sheet and resin with a thickness of several tens to several hundreds of microns as an exterior material is particularly lightweight and is expected to be used in various applications. Has been.

  Here, while the battery cell using a flexible laminate film as an exterior material is excellent in weight reduction, the strength is low compared to a square battery or a cylindrical battery using a thick metal plate as an exterior material, It has the problem of being vulnerable to external impacts.

  Moreover, when the battery capacity required by the device on the side to which the battery pack is connected increases, it is necessary to connect and use a plurality of battery cells. When a plurality of laminate-type battery cells are accommodated in the battery pack, they are stacked in the stacking direction or arranged in parallel with the inner surface of the outer case.

For example, Patent Document 1 (International Publication No. 2012/131802) discloses a battery pack that houses a battery connection structure in which stacked battery cells are connected by a substrate.
International Publication 2012/131802

  In the battery cell having a structure in which the electrode laminate is accommodated in the laminate film exterior material, the conductive foil portion that extends from the electrode laminate and is electrically connected to the drawer tab becomes fragile. In such a battery pack having a structure in which a plurality of battery cells are stacked, in order to improve the reliability, it was necessary to reliably protect the vicinity of the conductive foil in the laminate film exterior material of each battery cell. Conventionally, such protection is not always sufficient, and there has been a problem that the battery pack itself becomes vulnerable to vibration and impact.

  The present invention solves the above-described problems, and a battery pack according to the present invention includes a battery cell having a positive electrode extraction tab and a negative electrode extraction tab drawn from one side of a rectangular laminate film exterior material. A battery pack including a battery connection structure in which the adjacent battery cells are electrically connected to each other, and is in contact with the laminate film exterior material between the positive electrode extraction tab and the negative electrode extraction tab An inter-tab protection buffer member is arranged.

  In the battery pack according to the present invention, an inter-tab protection buffer member that contacts the laminate film exterior material is disposed between the positive electrode pull-out tab and the negative electrode pull-out tab, and such a battery pack according to the present invention. According to the above, it becomes possible to more reliably protect the vicinity of the conductive foil in the laminate film exterior material in the battery cell, and the battery pack itself can improve vibration resistance and impact resistance.

It is a figure which shows the battery cell 100 used for the battery pack 700 which concerns on embodiment of this invention. FIG. 4 is a diagram showing a state where a positive electrode extension tab member 125 is joined to the positive electrode pull-out tab 120 of the battery cell 100. It is a figure which shows the battery cell 100 to which the positive electrode extension tab member 125 was joined. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a top view of the battery cell 100 with which the insulating member 310 and the tab protection buffer member 314 were attached. It is a figure which shows the cross section before and behind the protection buffer member 314 between tabs being attached to the battery cell 100. FIG. It is a top view of the battery cell 100 with which the insulating member 310 and the tab protection buffer member 314 which were laminated | stacked on the even number step were attached. It is a perspective view of the wire harness used by manufacture of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure explaining the electric potential detection tab member 200 used when manufacturing the battery connection structure 500. FIG. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure explaining the return | turnback of the electric potential detection tab member. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the resistance welding process and folding process of three tab members. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows typically the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows typically the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows typically the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows typically the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows typically the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows typically the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows typically the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the battery connection structure 500 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of the battery pack 700 which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a battery cell 100 used in a battery pack 700 according to an embodiment of the present invention. As such a battery cell 100, a lithium ion secondary unit battery that is charged and discharged by moving lithium ions between a negative electrode and a positive electrode is used.

  The battery main body 110 of the battery cell 100 has an electrode laminate in which a plurality of sheet-like positive electrodes and a plurality of sheet-like negative electrodes are laminated via a separator, and an electrolyte solution (both not shown) are rectangular in a plan view. It has a structure accommodated in a laminate film exterior material 103. A positive electrode extraction tab 120 and a negative electrode extraction tab 130 are extracted from the first end 111 of the battery main body 110.

  Each of the positive electrode pull-out tab 120 and the negative electrode pull-out tab 130 has a flat plate shape, and is connected to the sheet-like positive electrode and the sheet-like negative electrode directly or via a lead body in the laminate film exterior material 103, respectively. Laminate film exterior material 103 is formed of a metal laminate film having a heat-sealing resin layer on the inner surface of the battery. More specifically, for example, two metal laminate films are stacked to form a laminate film exterior material 103, and an electrode laminate having a sheet-like positive electrode, a sheet-like negative electrode, and a separator and an electrolytic solution are accommodated therein. Thus, the outer periphery (first end 111, second end 112, two side ends 113) of the laminate film exterior material is heat-sealed, so that the inside is sealed.

  A conductive foil portion (not shown) extends from the sheet-like positive electrode, and these are connected to the positive electrode lead tab 120. In addition, conductive foil portions (not shown) extend from the sheet-like negative electrode, and these are connected to the negative electrode extraction tab 130. The conductive foil portion (not shown) as described above is accommodated in the laminate film exterior material 103.

  Here, metal pieces drawn out from the battery main body 110 made of the laminate film exterior material 103 such as the positive electrode extraction tab 120 and the negative electrode extraction tab 130 are referred to as “extraction tabs”, and are separated inside the laminate film exterior material 103. A sheet-like positive electrode or a sheet-like negative electrode laminated via a liquid electrolyte or an electrolytic solution is referred to as an “electrode”.

  In the electrode laminate, in addition to a laminate of a plurality of sheet-like positive electrodes and a plurality of sheet-like negative electrodes via a separator as described above, a laminate of a sheet-like positive electrode and a sheet-like negative electrode via a separator The thing which makes a laminated body by winding this and compressing this is also contained.

  In the battery cell 100 as described above, the positive electrode pull-out tab 120 is made of aluminum or an aluminum alloy, the negative electrode pull-out tab 130 is made of nickel, and other metal is plated with nickel (nickel plating). Materials such as nickel-plated copper) and nickel and other metal clads (nickel clad materials such as nickel-copper clad) are generally used. In other words, the battery cell 100 has a positive electrode extraction tab 120 containing aluminum and a negative electrode extraction tab 130 containing nickel. In this embodiment, a positive electrode extraction tab 120 made of aluminum and a negative electrode extraction tab 130 made of nickel are used.

  In the configuration in which the positive electrode pulling tab 120 containing aluminum of the battery cell 100 is directly connected to another conductive metal, the conductivity after a predetermined period of time may deteriorate due to a potential difference between the metals. There is.

  Therefore, in the present invention, the positive electrode extension tab 120 of the battery cell 100 is joined to the positive electrode extension tab member 125 containing nickel by resistance welding or ultrasonic welding to solve the problem of conductivity deterioration due to the potential difference problem. Like to do.

  The configuration for this will be described in more detail. As shown in FIG. 1, in constituting the battery connection structure 500, the aluminum positive electrode lead-out tab 120 in the battery cell 100 has a length a from the first end portion 111 and is made of nickel (or a material containing nickel). (Manufactured) has a length b (b> a) from the first end 111.

  Next, for the positive electrode extraction tab 120 made of aluminum having a length a, the positive electrode extension tab member 125 made of nickel is resistance welded or ultrasonically welded so that the length from the first end 111 becomes b. Etc. and joined (see FIGS. 2 and 3).

  Hereinafter, the entire extraction tab formed by joining the positive electrode extension tab member 125 may be referred to as a “positive electrode extraction tab”. As shown in FIG. 3, the positive electrode extension tab member 125 is added to the positive electrode extraction tab 120, whereby the length from the first end 111 becomes b as the entire positive electrode extraction tab.

  The entire positive electrode pull-out tab including the positive electrode pull-out tab 120 and the positive electrode extension tab member 125 added to the positive electrode pull-out tab 120 is in contact with the potential detection tab member 200 in the battery pack 700 according to the present invention. In this state, the battery connection structure 500 is configured. The potential detection tab member 200 is manufactured of nickel or a material containing nickel.

  As described above, in the battery pack 700 according to the present invention, in order to electrically connect the plurality of battery cells 100 in series, members containing nickel (addition tab member 125, potential detection tab member 200) are in contact with each other. Since the drawer tabs are connected to each other, the electrical connection portions of the adjacent unit batteries (battery cells 100) are electrically connected by the same kind of metal material, there is no problem of potential difference, and the electrical conductivity due to the passage of time Almost no deterioration occurs.

  Next, a battery connecting structure 500 in which a plurality of battery cells 100 configured as described above are stacked and adjacent battery cells 100 are electrically connected will be described, and a method for manufacturing the battery pack 700 will be described.

  Hereinafter, in the present embodiment, the case where seven battery cells 100 are stacked and these are connected in series to form a battery connection structure 500 will be described as an example, but the present invention is not limited to this case. In the present invention, the number of battery cells 100 stacked is arbitrary. In the present invention, when the battery cells 100 are electrically connected to each other, it is possible to appropriately select whether the connection form is a series connection or a parallel connection.

  FIG. 4 is a diagram showing a manufacturing process of the battery pack 700 according to the embodiment of the present invention. FIG. 4 shows a step of preparing the first battery cell 100 among the seven battery cells 100 to be stacked.

  FIG. 4 is a diagram showing a manufacturing process of the battery pack 700 according to the embodiment of the present invention. FIG. 9 shows a step of preparing the first battery cell 100 among seven battery cells 100 to be stacked.

  In the process of FIG. 4, the insulating member 310 for protecting the cell is disposed on the first end 111 side of the battery cell 100. Thereby, the battery cell 100 is protected by the insulating member 310. As the insulating member 310, a tape having flame retardancy and electrical insulation can be used. As will be described later, the battery cell 100 undergoes a process of joining the tabs together by resistance welding or the like. At this time, the battery cell 100 having the laminate film exterior material 103 is protected by the insulating member 310.

  After the insulating member 310 is attached as described above, the inter-tab protection buffer member 314 is subsequently provided between the positive electrode extraction tab 120 and the negative electrode extraction tab 130. Two inter-tab protection buffer members 314 are attached so as to sandwich the laminate film exterior material 103 between the positive electrode extraction tab 120 and the negative electrode extraction tab 130. The inter-tab protection buffer member 314 is a rectangular parallelepiped insulating resin member, and chloroprene rubber is suitable as the material. Further, when attaching the inter-tab protection buffer member 314, a fixing means such as a double-sided tape or an acrylic adhesive can be used.

  FIG. 5 is a top view of the battery cell 100 to which the insulating member 310 and the inter-tab protection buffer member 314 are attached. 6 is a cross-sectional view before (FIG. 6 (A)) and after (FIG. 6 (B)) the inter-tab protection buffer member 314 being attached to the battery cell 100. FIG. FIG. 6 shows an x-x ′ cross section of FIG. 5.

  In the battery pack 700 according to the present invention, it is particularly important that the inter-tab protection buffer member 314 is arranged so that the laminate film exterior member 103 is sandwiched between the inter-tab protection buffer member 314 and the electrode laminate. . FIG. 6B in which the inter-tab protection buffer member 314 is attached to the battery cell 100 shows a state in which the laminate film exterior material 103 is sandwiched between the inter-tab protection buffer member 314 and the electrode laminate.

  A conductive foil portion (not shown) extends from the sheet-like positive electrode and the sheet-like negative electrode constituting the electrode laminate, and these are connected to the lead-out tab of each electrode. The present inventors have confirmed that when the inter-tab protection buffer member 314 is provided as in the battery pack 700 according to the present invention, the stress on the conductive foil portion (not shown) can be relaxed.

  When the battery pack 700 receives an impact or vibration, the electrode laminate in the laminate film exterior material 103 of the battery cell 100 moves, and the conductive foil portion (not shown) is damaged as the electrode laminate moves. The possibility of receiving increases. On the other hand, the inter-tab protection buffer member 314 according to the present invention can efficiently suppress the movement of the electrode laminate, relieve stress on the conductive foil part (not shown), and near the conductive foil part. It is possible to more reliably perform the protection. Further, the hardness of the material used for the inter-tab protection buffer member 314 is selected appropriately for such a purpose. The hardness of the inter-tab protection buffer member 314 will be described later.

  In the battery pack 700 according to the present invention, an inter-tab protection buffer member 314 that is in contact with the laminate film exterior material 103 is disposed between the positive electrode pull-out tab 120 and the negative electrode pull-out tab 130. According to the battery pack 700 of the invention, it is possible to more reliably protect the battery cell 100 in the vicinity of the conductive foil portion in the laminate film exterior material 103, and the battery pack 700 itself has vibration resistance and impact resistance. Can be improved.

  The battery cells 100 to which the insulating members 310 and the inter-tab protection buffer members 314 as described above are attached are prepared for the number constituting the battery pack 700, but the battery cells 100 stacked in an even number of stages are illustrated in FIG. 7 is used. The surface to which the insulating member 310 is attached is different between the one shown in FIG. 5 (odd-stage melting) and the one shown in FIG. 7 (for even-numbered stages).

  Next, electrical connection between the battery cells 100 to be stacked will be described. FIG. 8 is a perspective view of a wire harness used in manufacturing the battery pack 700 according to the embodiment of the present invention.

  In the wire harness shown in FIG. 8, the potential detection tab member 200 is electrically and physically connected to the drawer tab of the battery cell 100 by resistance welding or the like. All of the potential detection tab members 200 are connected to signal lead wires 230 used for extracting potential information of the potential detection tab members 200 themselves. A connector member 260 is attached to the end of the signal lead wire 230 to which the potential detection tab member 200 is not connected, and the potential information can be taken out from the connector member 260.

  Further, among the battery cells 100 to be stacked, a power supply line 240 is attached to the potential detection tab member 200 connected to the drawer tab of the first battery cell 100 and the drawer tab of the last battery cell 100, The power of the plurality of battery cells 100 connected in series can be taken out from the power line 240. A power supply terminal portion 245 is attached to the end of the power supply line 240 that is not connected to the potential detection tab member 200, and the power can be taken out from the power supply terminal portion 245. Further, a fuse portion 243 is inserted in the middle of the power supply line used at a high potential among the two power supply lines 240.

  In the following description, the signal lead wire 230 and the power supply line 240 in the potential detection tab member 200 may be omitted in order to avoid complicated drawing.

  Returning to the manufacturing procedure of the battery pack 700. FIG. 9 is a diagram showing a manufacturing process of the battery pack 700 according to the embodiment of the present invention.

  As described above, when the insulating member 310 and the inter-tab protection buffer member 314 are attached to the battery cell 100, the potential detection tab member is then placed on the positive electrode pull-out tab 120 and the positive electrode extension tab member 125. 200 is placed. In the process shown in FIG. 9, the potential detection tab member 200 in which the signal lead wire 230 and the power supply line 240 are solder-connected is used.

  The positive electrode pull-out tab 120, the positive electrode extension tab member 125, and the potential detection tab member 200 shown in FIG. 9 are positive electrodes of the battery connection structure 500 itself in which seven battery cells 100 are connected in series. The power supply line 240 functions as a lead wire for the positive electrode of the battery connection structure 500. On the other hand, the signal lead wire 230 is used to detect the potential of the battery cell 100.

  Here, the electric potential detection tab member 200 will be described in more detail. FIG. 10 is a diagram illustrating the potential detection tab member 200 used when manufacturing the battery connection structure 500.

  10A is a diagram showing only the potential detection tab member 200, and FIG. 10B is a diagram showing the potential detection tab member 200 in which the signal lead wire 230 and the power supply line 240 are solder-connected. FIG. 10C is a diagram showing the potential detection tab member 200 to which the signal lead wire 230 is soldered.

  In the present invention, when assembling the battery connection structure 500, as the potential detection tab member 200, the signal lead wire 230 and the power supply wire 240 are already soldered as shown in FIGS. 10B and 10C. What is shown is used. This is a process after the potential detection tab member 200 is joined to the drawer tab, and if the signal lead wire 230 or the power supply wire 240 is soldered, it adversely affects the active material and the electrolyte in the battery cell 100 (both not shown). It is because it exerts.

  Examples of the material constituting the potential detection tab member 200 include nickel, a material obtained by applying nickel plating to another metal (nickel-plated material, for example, nickel-plated copper), and a clad of nickel and another metal (nickel clad material). For example, nickel-copper clad) is used.

  The potential detection tab member 200 is a flat plate member, and has a base 210 that is assumed to be superimposed on the drawer tab in the assembly process of the battery connection structure 500, and a protrusion 220 that protrudes from the base 210. doing.

  When the potential detection tab member 200 is overlapped with the drawer tab, a direction parallel to the direction in which the drawer tab is pulled out from the laminate film exterior member 103 is defined as the longitudinal direction of the base 210. The protruding portion 220 protrudes perpendicularly to the longitudinal direction of the base portion 210. The width of the base 210 (the length in the direction perpendicular to the longitudinal direction) is the same as the width of each drawer tab. The length of the base 210 in the longitudinal direction is such that when one end is overlapped with the end of the positive electrode extension tab member 125, the other end overlaps the insulating member 310. . A state in which the other end of the base 210 is overlapped with the insulating member 310 is shown in FIG.

  The base 210 of the potential detection tab member 200 is overlapped with the entire positive electrode tab composed of the positive electrode pull-out tab 120 and the positive electrode extension tab member 125, or is overlapped with the negative electrode pull-out tab 130, or the entire positive electrode tab. It overlaps with both the negative electrode extraction tabs 130 and is electrically and physically joined to them by resistance welding or the like.

  On the other hand, the protruding portion 220 of the potential detection tab member 200 is used as a conductive connection portion with the signal lead wire 230 and the power supply line 240.

  The end of the signal lead wire 230 that is not connected to the protruding portion 220 of the potential detection tab member 200 is connected to a conductive portion (not shown) of the connector member 260.

  When the end of the power supply line 240 that is not connected to the protruding part 220 of the potential detection tab member 200 is used as the positive power supply line of the battery connection structure 500, the power supply is connected via the fuse part 243. Connected to the terminal portion 245.

  When the end of the power supply line 240 that is not connected to the protruding portion 220 of the potential detection tab member 200 is used as the negative power supply line of the battery connection structure 500, it is directly connected to the power supply terminal portion 245. Is done.

  In the manufacturing process of the battery connection structure 500, the potential detection tab member 200 is folded together with the joined drawer tabs. In FIGS. 10B and 10C, a line that is to be folded back in the assembly process is indicated by a dotted line. The process of folding back the drawer tab and the potential detection tab member 200 will be described later.

  Note that, when the assembled battery is manufactured by omitting the potential detection tab member 200 used in the present invention, since the lead is connected to the unit cell in advance, the lead is a container of the unit cell when stacked. There is a possibility of contact with other poles. Moreover, since it is necessary to laminate | stack a single cell, putting together a long lead to prevent it, productivity will fall. In order to prevent this, it is preferable to employ a wire harness in which the potential detection tab member 200 is used for assembling the battery pack 700.

  In the subsequent step shown in FIG. 11, the potential detection tab member 200 placed on the positive electrode extension tab 120 and the positive electrode extension tab member 125 is joined to the positive electrode extension tab member 125 by resistance welding. In this embodiment, resistance welding is used for joining the tabs, but other joining methods such as ultrasonic welding can also be used.

  Also, the first end-side cell protection buffer member 330 functioning as a cushion member is placed under the positive electrode pull-out tab 120, the positive electrode extension tab member 125, the potential detection tab member 200, and above and below the positive electrode pull-out tab 120. Is done. It is preferable that the first end-side cell protection buffer member 330 has electrical insulation and cushioning properties and is flame retardant. Further, the first end-side inter-cell protection buffer member 330 does not fill a space corresponding to bc described later.

Here, the first end-side cell protection buffer member 330 is a rectangular parallelepiped insulating resin member, and chloroprene rubber is suitable as the material. The same material as the inter-tab protection buffer member 314 can be used. Moreover, the 1st end side cell protection buffer member 330 can also be integrated with the tab protection buffer member 314 as needed. (The tab-to-tab protection buffer member 314 and the first end-side cell protection buffer member 330 can be formed as an L-shaped or T-shaped member as one member.)
In the step shown in FIG. 12, a step of folding back the positive electrode extraction tab 120, the positive electrode extension tab member 125, and the potential detection tab member 200 in the direction opposite to the direction in which the positive electrode extraction tab 120 is extracted from the laminate film exterior material 103 is performed. To do.

  As shown in FIG. 13, the length of the entire positive electrode tab member is c from the first end portion 111 in the folding process as described above. The space corresponding to the folded back portion bc is used when the battery cells 100 are stacked in the subsequent steps.

  In the folding step, when the positive electrode pull-out tab 120, the positive electrode extension tab member 125, and the potential detection tab member 200 are folded back, the respective leading ends are placed on the insulating member 310 so that The dimensions of the tab and the insulating member 310 are defined. With such an insulating member 310, the laminate film exterior material 103 of the battery cell 100 can be protected from a pull-out tab, a tab member, or the like.

  Further, in the battery pack 700 according to the present invention, since the folding process as described above is performed on the drawer tab, the tab member, and the like, the volume efficiency of the battery pack 700 can be improved.

  Moreover, according to the battery pack 700 which concerns on this invention, manufacturability can also be improved by the space which can be provided by a folding | returning process, and the improvement of a yield can also be aimed at.

  Further, in the battery pack 700 according to the present invention, in the folding process as described above, folding is performed so that the position of the protruding portion 220 of the potential detection tab member 200 is not changed by folding. (Refer also to the line to be folded in FIGS. 10B and 10C.) Thereby, there is no influence of the stress on the protrusion 220 due to the folding of the potential detection tab member 200, and therefore the protrusion 220 is not affected. There is no influence on the connected signal lead wire 230, the power supply line 240, and the like.

  Further, with reference to FIG. 13, the arrangement relationship between the first end-side inter-cell protection buffer member 330 and the inter-tab protection buffer member 314 will be seen. The inter-tab protection buffer member 314 is disposed so as to be closer to the electrode laminate (not shown) in the laminate film exterior material 103 than the first end-side cell protection buffer member 330. More specifically, as shown in FIG. 13, the inter-tab protection buffer member 314 is closer to the electrode stack (not shown) by a length of approximately d than the first end-side cell protection buffer member 330. doing. According to such an arrangement, stress on the conductive foil part (not shown) can be relaxed and protection in the vicinity of the conductive foil part can be performed.

  In the step shown in FIG. 14, the first end-side cell protection buffer member 330 that functions as a cushion member is placed on the positive electrode pull-out tab 120, the positive electrode extension tab member 125, and the potential detection tab member 200.

  Next, the process of laminating battery cells is shown in FIG. The battery cell to be stacked is given a prime symbol (') to distinguish it from the first battery cell.

  15 and 16, when the second battery cell 100 ′ is stacked on the first battery cell 100, the main body portions of the laminate film exterior material 103 are provided with two double-sided adhesive tapes 320. Use to fix.

  At this time, the negative electrode extraction tab 130 ′ of the second battery cell 100 ′ comes on the positive electrode extraction tab 120 of the first battery cell 100, and the negative electrode extraction tab 130 ′ of the first battery cell 100 is arranged. The positive electrode pull-out tab 120 ′ and the positive electrode extension tab member 125 ′ of the second battery cell 100 ′ are on the upper side.

  Further, only a signal lead wire (not shown) is soldered between the negative electrode pull-out tab 130 of the first battery cell 100 and the positive electrode pull-out tab 120 ′ and the positive electrode extension tab member 125 ′ of the second battery cell 100 ′. A joined potential detection tab member 200 'is disposed. That is, the three tab members are aligned when viewed from the vertical direction. In addition, the crosses indicated by the three tab members in FIG. 15 indicate the locations where resistance welding is to be performed.

  Here, the end portion of the positive electrode extension tab member 125 ′, the end portion of the potential detection tab member 200 ′, and the end portion of the negative electrode lead tab 130 are substantially aligned when viewed from the vertical direction (that is, all end portions). However, the length from the first end portion 111 is approximately b).

  Further, in stacking the first battery cell 100 and the second battery cell 100 ′, the first end-side cell protection buffer member 330 is attached as illustrated.

  In the subsequent step shown in FIG. 17, three tab members (a negative electrode pull-out tab 130, a potential detection tab member 200 ′, and a positive electrode extension tab member 125 ′) aligned in the vertical direction are connected to the anvil portion of the resistance welding apparatus 1000 from above and below. 1010 and the horn 1020 are sandwiched and resistance welding is performed.

  FIG. 18 is a diagram showing a resistance welding process and a folding process of three tab members (a negative electrode extraction tab 130, a potential detection tab member 200 ', and a positive electrode extension tab member 125'). FIG. 18 is a side view of the drawer tab and the potential detection tab member drawn from the laminate film exterior material of the battery cell.

  FIG. 18A shows the three tab members (negative electrode pull-out tab 130, potential detection tab member 200 ′, positive electrode extension tab member 125 ′) subjected to resistance welding shown in FIG. , The state set between the horn part 1020 is shown.

  FIG. 18B shows a state in which the welding operation by the resistance welding apparatus 1000 is executed and the three tab members (the negative electrode extraction tab 130, the potential detection tab member 200 ′, and the positive electrode extension tab member 125 ′) are resistance welded. ing.

  FIG. 18C is a diagram showing a state where three resistance-welded tab members (negative electrode pull-out tab 130, potential detection tab member 200 ′, and positive electrode extension tab member 125 ′) are taken out from the resistance welding apparatus 1000. .

  FIG. 18D shows a direction in which three tab members (negative electrode pull-out tab 130, potential detection tab member 200 ′, positive electrode extension tab member 125 ′) subjected to resistance welding are pulled out from the laminate film exterior material. In the opposite direction, the process of folding is shown.

  In such a folding process, the length of the three resistance-welded tab members (the negative electrode extraction tab 130, the potential detection tab member 200 ′, and the positive electrode extension tab member 125 ′) is c from the first end 111. . As shown in the figure, when the space corresponding to the folded portion bc is stacked in the subsequent steps and the tab members are resistance-welded to each other, the anvil portion 1010 and the horn portion 1020 of the resistance welding apparatus 1000 It is used as a space for entering.

  FIG. 19 shows a state in which a folding process is performed on three tab members (negative electrode pull-out tab 130, potential detection tab member 200 ', positive electrode extension tab member 125') subjected to resistance welding.

  Here, the outline of manufacturing the battery pack 700 according to the present invention will be briefly reviewed. 20 to 26 are diagrams schematically showing a manufacturing process of the battery pack 700 according to the embodiment of the present invention.

  In the series of figures, the battery cells 100 are given ordinal numbers such as “first” and “second” in the order of stacking. Further, a positive sign tab 120 pulled out from the battery cell 100 and a positive electrode extension tab member 125 added to the positive electrode pull-out tab member 120 have a (+) symbol, and a negative electrode pull-out tab 130 drawn from the battery cell 100 has a negative sign (-). A symbol is attached. In the description of the manufacturing process with the schematic diagram, they are referred to as (+) tab, (−) tab, and the like.

  Ordinal numbers such as “first” and “second” for the stacking step of stacking the battery cells, the connecting step of connecting the tab members of the battery cells by resistance welding, and the folding step after the connecting step Was attached. Further, since it becomes complicated, the potential detection tab member is not shown.

  FIG. 20 shows a step of preparing the first battery cell. A potential detection tab member (not shown) is connected to the (+) tab of the first battery cell, and these are folded back.

  FIG. 21 illustrates a step of laminating the second battery cell (first laminating step) on the first battery cell, and the (−) tab of the first battery cell and the second battery cell. The state which performed the process (1st connection process) which connects (+) tab of this and the electric potential detection tab member not shown is shown.

  Subsequently, as shown in FIG. 22, a step of folding back the (−) tab of the first battery cell, the (+) tab of the second battery cell, and a potential detection tab member (not shown) (first folding step). ).

  FIG. 23 illustrates a step of laminating the third battery cell on the second battery cell (second lamination step), and the (−) tab of the second battery cell and the third battery cell. The state which performed the process (2nd connection process) which connects (+) tab of this and the electric potential detection tab member not shown is shown.

  Subsequently, as shown in FIG. 24, a step of folding back the (−) tab of the second battery cell, the (+) tab of the third battery cell, and a potential detection tab member (not shown) (second folding step). ).

  FIG. 25 illustrates a process of stacking the fourth battery cell on the third battery cell (third stacking process), the (−) tab of the third battery cell, and the fourth battery cell. This shows a state in which the step (third connection step) of connecting the (+) tab of (2) and a potential detection tab member (not shown) is performed.

  Here, in practice, the third connection process is performed using the resistance welding apparatus 1000. At this time, the space into which the anvil part 1010 and the horn part 1020 of the resistance welding apparatus 1000 enter is generated by the first folding process. Space can be utilized.

  In order to provide such a space, as shown in FIG. 26, the (−) tab of the third battery cell, the (+) tab of the fourth battery cell, and a potential detection tab member (not shown) are provided. A folding step (third folding step) is performed.

  In the manufacture of the battery pack 700 as described above, as shown in the above-described series of schematic diagrams, a space for connecting the battery cells can be secured by sequentially performing the folding process. It becomes possible to connect between them efficiently. As described above, the battery pack 700 according to the present invention does not require an extra part such as a substrate for connecting the battery cells, and also reduces the labor and cost in manufacturing associated with the extra part. be able to.

  In the present embodiment, the seventh battery cell 100 is stacked by repeating the stacking process → connection process → folding process as described above, and the signal is placed on the negative electrode pull-out tab 130 of the seventh battery cell 100. The potential detection tab member 200 in which the lead wire 230 and the power supply wire 240 are solder-connected is placed.

  Now, when the folding | returning process as shown in FIG. 19 is implemented, as shown in FIG. 27, the 1st end side inter-cell protection buffer member 330 will be attached.

  Subsequently, in the present embodiment, the inter-cell reinforcing member 370 is inserted before the third battery cell is stacked. For the inter-cell reinforcing member 370, an insulating member made of a synthetic resin having a relatively high synthesis can be used.

  Since the laminate film exterior material 103 of the battery cell 100 is flexible, if the number of stacked battery cells 100 is increased to increase the weight, the vibration resistance may be greatly reduced. Therefore, the inter-cell reinforcing member 370 is provided between the battery cells.

  Such inter-cell reinforcing members 370 are preferably provided every three layers or at an optional interval of three layers or less in the number of battery cells stacked. In addition, it is also a preferred embodiment that the inter-cell reinforcing member 370 is provided with a side plate portion 377 so that the side surface of the battery cell can be protected.

  In the present embodiment, the inter-cell reinforcing member 370 is bent at the bent portion 375 at the opposite side edges of the flat plate portion 373 arranged so as to be sandwiched between the battery cells 100, and the flat plate portion. It has a structure having two side plate portions 377 extending vertically from 373. That is, in the present embodiment, the inter-cell reinforcing member 370 has a U-shaped cross section. In this case, the side surface of the upper or lower battery cell in the stacking direction can be protected by the side plate portion 377.

  On the other hand, the inter-cell reinforcing member 370 may have an H-shaped cross section. In this case, the side surfaces of the upper and lower battery cells in the stacking direction can be protected by the side plate portion 377.

  Now, two inter-cell reinforcing members 370 as described above are layered, and as shown in FIGS. 29 and 30, seven battery cells 100 are stacked to obtain the basic structure of the battery connection structure 500. 20 shows attachment of the first end-side cell protection buffer member 330, and FIG. 30 shows a folding process of a tab member or the like including the negative power supply line 240 as the battery pack 700.

  In the step shown in FIG. 31, a plurality of second end-side inter-cell protection buffer members 340 that are cushion members having flame resistance are attached to the second end 112 side of the plurality of battery cells 100. The second end-side cell protection buffer member 340 can be made of the same material as the first end-side cell protection buffer member 330.

  FIG. 32 is a diagram showing the battery connection structure 500 completed as described above. 32A is a top view of the battery connection structure 500, and FIG. 32B is a side view of the battery connection structure 500. FIG.

  Next, when the battery connection structure 500 as described above is accommodated in the case body of the battery pack 700, the battery connection structure 500 is packed so as to protect the battery connection structure 500. The configuration of such a battery package 600 will be described with reference to FIG.

  In the battery connection structure 500, the portion where the inter-tab protection buffer member 314 is disposed between the first end-side cell protection buffer members 330 is formed as a recess. A position stabilizing buffer 501 is disposed.

  The first position stabilizing buffer material 501 is a rectangular parallelepiped insulating resin member, and chloroprene rubber is suitable as the material. However, the hardness of the material used for the first position stabilizing buffer 501 is set higher than the hardness of the material used for the inter-tab protection buffer member 314.

  The inter-tab protection buffer member 314 is mainly expected to protect the conductive foil portion (not shown) accommodated in the laminate film exterior material 103. In contrast, the first position stabilization buffer material 501 includes In addition to the protective function, a positioning function of the battery connection structure 500 is also expected. For this reason, (hardness of the first position stabilizing buffer member 501)> (inter-tab protection buffer member 314).

  Note that a second position stabilizing cushioning material 552, which will be described later, has the same material and function as the first position stabilizing cushioning material 501, and (second position stabilizing cushioning material 552)> (inter-tab protection cushioning member 314). .

That is, in the battery pack 700 according to the present invention,
(Hardness of first position stabilizing cushioning material 501) = (second position stabilizing cushioning material 552)>
(Hardness of inter-tab protection buffer member 314) = (Hardness of first end-side cell protection buffer member 330) = (Hardness of second end-side cell protection buffer member 340)
Thus, it was confirmed that the hardness and vibration resistance of the battery pack 700 were improved when the hardness was actually set.

  Now, returning to the configuration of the battery package 600, the first position stabilizing buffer 501 is fixed to the first end-side reinforcing plate 521 via the double-sided adhesive tape 511. The first end reinforcing plate 521 is fixed so as to be covered with an adhesive tape 531 made of a polyester base material. In addition, a second position stabilizing cushion 552 is disposed outside the adhesive tape 531.

  In addition, a first surface side reinforcing plate 525 made of synthetic resin is attached to the battery connection structure 500 via a double-sided adhesive tape 515. Further, when the battery pack 700 is accommodated in the case body, a first surface side spacer 545 made of polycarbonate is disposed.

  In addition, a second surface side reinforcing plate 526 made of synthetic resin is attached to the battery connection structure 500 via a double-sided adhesive tape 516 (not shown). When the battery pack 700 is accommodated in the case body, a polycarbonate second surface side spacer 546 is disposed.

  Further, a second end-side reinforcing plate 522 made of synthetic resin is attached to the battery connection structure 500 via a double-sided adhesive tape 512 (not shown). When the battery pack 700 is accommodated in the case body, a second end side spacer 542 made of chloroprene is disposed.

  Further, both side surfaces of the battery connection structure 500 are fixed so as to be covered with adhesive tapes 533 and 534 made of a polyester base material. Further, the periphery of the battery connection structure 500 is surrounded and fixed by an annular surrounding resin tape 567 made of insulating resin.

  FIG. 33 schematically illustrates a process in which the battery packaging body 600 configured as described above is accommodated in the first case body 670 and the second case body 680 to form the battery pack 700 according to the present invention. Yes.

  A BMU (battery management unit) board 690 is attached to the first case body 670. A board-side power terminal 695 provided on the BMU board 690, a power terminal 245 on the battery packing body 600 side, Are combined, and the battery package 600 is accommodated in the case.

  In the battery pack 700 according to the present invention as described above, an inter-tab protection buffer member 314 that is in contact with the laminate film exterior material 103 is disposed between the positive electrode extraction tab 120 and the negative electrode extraction tab 130. According to such a battery pack 700 according to the present invention, it becomes possible to more reliably protect the battery cell 100 in the vicinity of the conductive foil portion in the laminate film exterior material 103, and the battery pack 700 itself has vibration resistance, Impact resistance can be improved.

DESCRIPTION OF SYMBOLS 100 ... Unit cell 103 ... Laminate film exterior material 105 ... Electrode lamination | stacking area | region 110 ... Battery main-body part 111 ... 1st edge part 112 ... 2nd edge part 113 ... Side edge Portion 119 ... Chamfered portion 120 ... Positive electrode extraction tab 125 ... Positive electrode extension tab member 130 ... Negative electrode extraction tab 200 ... Potential detection tab member 210 ... Base 220 ... Projection 230 ..Signal lead wire 240 ... Power supply line 243 ... Fuse portion 245 ... Power supply terminal portion 260 ... Connector member 310 ... Insulating member (for cell protection)
314 ... Inter-tab protection cushioning member (cushion member, fourth cushioning material)
320... Double-sided adhesive tape 330... First end-side cell protection buffer member (cushion member, third buffer material)
340 ... Second end side inter-cell protection buffer member (cushion member, third buffer material)
370 ... inter-cell reinforcing member 373 ... flat plate part 375 ... bent part 377 ... side plate part 500 ... battery connection structure 501 ... first position stabilizing cushion (cushion member, first Cushioning material)
511 ... Double-sided adhesive tape 512 ... Double-sided adhesive tape 515 ... Double-sided adhesive tape 516 ... Double-sided adhesive tape 521 ... First end-side reinforcing plate 522 ... Second end-side reinforcing plate 525- ..First surface side reinforcing plate 526 ... Second surface side reinforcing plate 531 ... Adhesive tape (polyester substrate)
533 ... Adhesive tape (polyester substrate)
534 ... Adhesive tape (polyester substrate)
542 ... 2nd end side spacer 545 ... 1st surface side spacer 546 ... 2nd surface side spacer 552 ... 2nd position stabilization buffer material (cushion member, 2nd buffer material)
567... Surrounding resin tape 600... Battery packing body 670... First case body 680... Second case body 690. Part 700 ... Battery pack 1000 ... Resistance welding apparatus 1010 ... Anvil part 1020 ... Horn part

Claims (7)

A battery pack including a battery connection structure in which a plurality of battery cells each having a positive electrode extraction tab and a negative electrode extraction tab drawn from one side of a rectangular laminate film exterior material are stacked and the adjacent battery cells are electrically connected There,
A battery pack in which an inter-tab protection buffer member that contacts the laminate film exterior material is disposed between the positive electrode extraction tab and the negative electrode extraction tab. The laminate film exterior material contains an electrode laminate,
The battery pack according to claim 1, wherein the inter-tab protection buffer member is disposed so that the laminate film exterior member is sandwiched between the inter-tab protection buffer member and the electrode laminate. The battery pack according to claim 1 or 2, wherein an inter-cell protection buffer member is disposed so as to sandwich the positive electrode extraction tab and the negative electrode extraction tab. The battery pack according to claim 3, wherein the inter-tab protection buffer member is closer to the electrode stack than the inter-cell protection buffer member. The battery connection structure is accommodated in a case body,
The battery pack according to any one of claims 1 to 4, wherein a position stabilizing buffer material is disposed between the battery connection structure and the case body. The battery pack according to any one of claims 1 to 5, wherein a hardness of the position stabilizing buffer material is higher than that of the inter-tab protection buffer member. The battery pack according to any one of claims 1 to 6, wherein the hardness of the position stabilizing buffer material is higher than that of the inter-cell protective buffer member.

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