JP2008192570A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent diffusion of generated heat even though a part of a battery cell is abnormally heated up. <P>SOLUTION: A battery pack comprises a plurality of battery cells 1 respectively stored in cylindrical external cans and respectively displaying positive electrodes and negative electrodes at opposed end faces, conductive leads 3 for electrically connecting the respective battery cells 1, and one or more of separators 4 with isolation and heat insulation. The plurality of battery cells 1 is set up to be a line of battery cell row 2 by connecting with each other at an electrode connecting faces 9 where a positive electrode face and negative electrode face are opposed with each other in the longitudinal direction of the external can, a plurality of battery cell rows 2 are lined approximately in parallel in the longitudinal direction of the external can, the electrode connecting faces 9 of adjacent battery cell rows 2 are located at an approximately same plain face, and the battery cells 1 are electrically connected with the electrode connecting faces 9 via the leads 3. The separator 4 is arranged to cross with the electrode connecting face 9 between the battery cell rows 2, and has an opening as a slit 6 in order to insert the lead 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a battery pack in which a plurality of cylindrical batteries are connected in series and / or in parallel, and more particularly to a battery pack used for portable equipment such as a notebook computer.

  In recent years, battery packs (packed batteries) or assembled batteries used as power sources for portable electric devices such as notebook computers and mobile phones have been increasingly required to have high output, and lithium ions with excellent efficiency per unit volume. A battery or the like is employed as a secondary battery. Lithium ion batteries have high output but may generate heat for some reason. In particular, the battery pack has a high output by connecting a large number of secondary batteries in series. Therefore, a large number of battery cells are arranged adjacent to each other. In such a battery pack, if heat is generated in a part of the battery cells, heat may propagate to adjacent battery cells and thermal runaway may spread. For this reason, a structure that can stably use the battery pack while avoiding such thermal runaway is eagerly desired.

In order to reduce heat conduction between battery cells, a structure in which spacers having heat insulation properties are arranged between adjacent battery cells is known (for example, Patent Document 1). An example of the arrangement of battery cells and spacers in such a battery pack is shown in FIG. As shown in this figure, a separator 104 is interposed between battery cell rows 102 in which cylindrical battery cells 101 are connected in the longitudinal direction. In this configuration, the heat insulation of the battery cell 101 is achieved at the side surface portion of the outer can of the battery cell 101.
JP 2005-317455 A

  However, the conventional structure has a problem that heat insulation cannot be achieved in the vicinity of the electrode connection surface on the end surface of the battery cell, and heat generation cannot be prevented from diffusing between the battery cell rows. In particular, as a result of the analysis of the mechanism leading to thermal runaway by the present inventors, one of the main causes of the propagation of the heat generation of the battery cell to other battery cells is due to the release of internal gas at the end face of the outer can. It turned out to be. Based on FIG. 22, how the heat of one battery cell propagates to another battery cell will be described. Here, let us consider a state in which the upper left battery cell A in the figure among the plurality of battery cells arranged in a matrix as shown in FIG. Each battery cell 101 is provided with a safety valve 105 that is opened at a pressure equal to or higher than a predetermined value, in case the internal pressure of the outer can rises abnormally. Since the safety valve 105 is opened when the battery cell 101 abnormally generates heat, the flammable gas discharged from the safety valve 105 to the outside of the outer can can be ignited. In this case, as shown in FIG. 22 (b), the heat of the combusting gas propagates from the electrode edge portion to the lower battery cell B in the figure, and as a result, the safety valve 105 of the battery cell B is forcibly opened. Thus, combustible gas is released from the safety valve 105. And as shown in (c) of Drawing 22, the situation which this gas ignites may arise. And as shown to (d) of FIG. 22, when the battery cell B is heated from an opening end, as a result, abnormal heat_generation | fever and it may be in a thermal runaway state. Similarly, abnormal heat generation propagates to a battery cell (not shown) located below battery cell B in the same manner.

  As described above, according to the test conducted by the present inventors, the mechanism by which the heat of the abnormally heated battery cell propagates is propagated and diffused to the adjacent battery cells in the vertical direction in FIG. It became clear that the factor was dominant. It has been found that the conventional configuration is not effective for such a heat propagation mechanism.

  Furthermore, in FIG. 22, the gas discharged from the battery cell in which the thermal runaway is diffused in the vertical direction is directly injected to the bottom of the battery cell adjacent in the series direction (longitudinal direction), so that the battery cell in the series direction is also abnormal. It may generate heat and run out of heat.

  The present invention has been made based on such knowledge of the present inventors. A main object of the present invention is to provide a battery pack that can effectively prevent the diffusion of some of the battery cells even when abnormal heat is generated.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, a battery pack according to the present invention is a battery pack in which a plurality of battery cells are connected in series and / or in parallel, each of which is housed in a cylindrical outer can and has a positive electrode on the opposite end face. And a plurality of battery cells in which the negative electrode is exposed, a conductive lead for electrically connecting the battery cells, and an insulating and heat insulating material interposed between the battery cells. The plurality of battery cells are connected to each other by an electrode connecting surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a battery cell array. A plurality of battery cells arranged in parallel with each other in the longitudinal direction of the can, the electrode connection surfaces of adjacent battery cell rows are substantially the same plane, the battery cells are electrically connected to each other through the leads, and the separator is a battery cell. Between the rows, the electrode connection surface They are arranged to intersect, and the separator is open the slit for inserting the lead. As a result, the connection region between the electrodes between the battery cell rows is insulated by the separator and physically partitioned by the heat insulating separator, so that even if some of the battery cells may abnormally generate heat, the battery Heat can be prevented from propagating beyond the cell row, and safety and reliability can be improved.

  The battery cell is opened when the internal pressure of the outer can becomes higher than a predetermined value, and a safety valve for releasing the gas inside the outer can to the outside can be provided on the positive electrode side. Thereby, even if the gas discharged from the safety valve may be ignited, it is possible to prevent the heat generation from spreading over adjacent rows.

  Further, the separator can be disposed so that the cross section is substantially cross-shaped and is interposed between adjacent battery cell rows and on the electrode connection surface. Thereby, it is possible to achieve both heat insulation at the boundary surface between the battery cell rows and the electrode connection surface of the battery cells constituting the battery cell row with one separator, and it is possible to more effectively prevent heat propagation.

  The other battery pack is a battery pack in which a plurality of battery cells are connected in series and / or in parallel, each of which is housed in a cylindrical outer can, and has a positive electrode and a negative electrode exposed on opposite end faces. A plurality of battery cells, a lead having electrical conductivity for electrically connecting the battery cells, and one or more separators having insulation properties and heat insulation properties interposed between the battery cells. The battery cells are connected to each other by an electrode connection surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a battery cell row, and the battery cell rows are substantially parallel to the longitudinal direction of the outer can. The electrode connection surfaces of the adjacent battery cell rows arranged in a plurality are arranged in substantially the same plane, the battery cells are electrically connected at the electrode connection surface via leads, and the separator is orthogonal to the longitudinal direction of the battery cell rows. Intervene on the electrode connection surface Are arranged to, lead is U song so as to sandwich both surfaces of the separator may be connected to the battery cells to each other. Thereby, the heat conduction to the longitudinal direction of a battery cell row | line | column can be blocked | prevented with a separator.

  Furthermore, the other battery pack is a battery pack in which a plurality of battery cells are connected in series and / or in parallel, and each battery pack is housed in a cylindrical outer can, and a positive electrode and a negative electrode are respectively exposed on opposite end faces. A plurality of battery cells, and the plurality of battery cells are connected to each other by an electrode connection surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a single battery cell array. A plurality of adjacent battery cell rows may be arranged in an offset manner so that the electrode connection surfaces of the adjacent battery cell rows are not substantially coplanar and are arranged in parallel in the longitudinal direction of the outer can. As a result, even if some of the battery cells may generate abnormal heat, the electrode connection surface is not close to the adjacent battery cell row, preventing the heat from propagating beyond the battery cell row. It is possible to improve safety and reliability.

  Furthermore, the other battery pack is a battery pack in which a plurality of battery cells are connected in series and / or in parallel. Each battery pack is housed in a cylindrical outer can and has a positive electrode and a negative electrode exposed on opposite end surfaces. The battery cell is opened when the internal pressure of the outer can becomes higher than a predetermined value, and a safety valve that releases the gas inside the outer can to the outside is provided on either the positive electrode side or the negative electrode side. The plurality of battery cells are provided on one side, and are connected to each other by an electrode connection surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can. The electrode connection surfaces of adjacent battery cell rows are arranged substantially in the same plane, the battery cells are electrically connected to each other through the leads, and the battery cell rows are adjacent to each other. The battery cell positive electrode And it may be arranged battery cells as the negative electrode surface are opposite to each other. As a result, the electrode surface provided with the safety valve is reversed between adjacent battery cell rows, so even if the gas released from the safety valve may ignite, the adjacent battery cell row is provided with a safety valve. Therefore, the possibility that the safety valve is opened and the gas is ignited can be reduced.

  Furthermore, the other battery pack is a battery pack in which a plurality of battery cells are connected in series and / or in parallel. Each battery pack is housed in a cylindrical outer can and has a positive electrode and a negative electrode exposed on opposite end surfaces. The battery cell is opened when the internal pressure of the outer can becomes higher than a predetermined value, and a safety valve that releases the gas inside the outer can to the outside is provided on either the positive electrode side or the negative electrode side. A plurality of battery cells are connected to each other at an electrode connection surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a battery cell array. Constitutes a battery cell row only by battery cells provided with safety valves on the same surface side of either the positive electrode surface side or the negative electrode surface side, and the connected battery cell rows are approximately in the longitudinal direction of the outer can. Adjacent battery cell rows arranged in parallel in parallel The electrode connection surfaces are substantially the same plane, and the battery cells are electrically connected to each other through the leads, the battery cell rows are adjacent to each other, and the electrode surfaces provided with safety valves are opposite to each other. You may arrange | position a battery cell so that it may become. As a result, the electrode surface provided with the safety valve is reversed between adjacent battery cell rows, so even if the gas released from the safety valve may ignite, the adjacent battery cell row is provided with a safety valve. Therefore, the possibility that the safety valve is opened and the gas is ignited can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows. Moreover, the member shown by the claim is not what specifies the member of embodiment. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

(Embodiment 1)
1 to 5 show a battery pack 10 according to Embodiment 1 of the present invention. The battery pack 10 can be used as a battery for various portable electric devices. Here, a battery pack applied to a battery for a notebook computer is shown as an example. The battery pack 10 is formed by connecting a plurality of battery cells 1 in series and / or in parallel. As shown in FIGS. 1 to 4, the battery pack 10 is housed in a case 7 and attached to various electronic devices.

  The arrangement of the plurality of battery cells 1 constituting the battery pack 10 is shown in the plan view of FIG. 5 and the schematic plan view of FIG. In this battery pack 10, a plurality of battery cells 1 are connected in series in the longitudinal direction to form a battery cell row 2, and the plurality of battery cell rows 2 are arranged in parallel. Further, the end surfaces of the battery cells 1 are made into electrode connection surfaces 9 for connecting the positive electrode and the negative electrode through the leads 3, and the electrode connection surfaces 9 are aligned on the same surface in the battery cell rows 2 arranged in parallel. Thus, one lead 3 is arranged so as to straddle the battery cell row 2. In the example of FIG. 6, three battery cells 1 are linearly connected in series to form a battery cell array 2, and further, two battery cell arrays 2 are connected in parallel to each battery cell 1, for a total of 6 A battery pack 10 is composed of the battery cells 1. Further, in the illustrated battery pack 10, the electrodes of the four battery cells 1 are connected by one lead 3 on the electrode connection surface 9. Furthermore, the battery pack of the figure arrange | positions the separator 4 which has insulation and heat insulation between adjacent battery cell row | line | columns 2. FIG. The separator 4 is disposed so as to intersect the electrode connection surface 9.

  In the illustrated battery pack 10, six battery cells 1 are connected in two lines and three lines. However, the battery pack of the present invention does not limit the arrangement state of the plurality of battery cells. In the battery pack, the number of battery cells connected in a straight line can be one or two, or four or more, and the number of battery cell arrays arranged in parallel can be three or more. Furthermore, the battery pack does not necessarily need to connect adjacent battery cells in parallel with the battery cell rows arranged in parallel to each other in the same direction, and may be in the opposite direction.

[Battery cell 1]
As the battery cell 1, a cylindrical battery covered with a cylindrical outer can is used. Secondary batteries such as lithium ion secondary batteries, nickel metal hydride batteries, and nickel cadmium batteries can be used for such battery cells. A primary battery may be used. However, the battery cell can also be a prismatic battery with an outer can having a rectangular tube shape. The electrode terminals of the battery cell 1 are connected in series or in parallel. Furthermore, it is connected to a control circuit (not shown) at the end of the battery pack 10 and measures the voltage, current, temperature, etc. of each battery cell 1 by the control circuit, determines the battery capacity and the required charge / discharge amount, etc. Control such as charging and discharging is performed.

  The battery cell 1 is provided with a safety valve 5 that opens when the internal pressure of the outer can rises abnormally and releases the gas inside the outer can. The safety valve 5 is provided on the positive electrode side of the battery cell 1. However, a safety valve may be provided on the negative electrode side.

[Lead 3]
The plurality of battery cells 1 arranged adjacent to each other are electrically connected via leads 3 having conductivity. In the lead 3, a plurality of battery cells 1 arranged in the longitudinal direction of the outer can are connected to each other by an electrode connection surface 9 in which the positive electrode surface and the negative electrode surface are opposed to each other to form a battery cell array 2. Furthermore, the lead 3 electrically connects the positive and negative electrodes of the electrode connection surface 9 located on substantially the same plane of the plurality of battery cell rows 2 arranged in parallel to the longitudinal direction of the outer can. That is, the lead 3 connects the battery cells 1 constituting the battery cell row 2, that is, the battery cells 1 adjacent in the axial direction in series, and the battery cells 1 of the battery cell rows 2 adjacent to each other, that is, the row direction. The battery cells 1 adjacent to each other are connected in parallel.

  In the illustrated battery pack 10, four battery cells 1 are connected in two rows and two on the electrode connection surface 9. The lead 3 is a metal plate and is spot-welded or laser-welded to be connected to the electrode of the battery cell 1. As this lead 3, for example, as shown in FIG. 7, a metal plate cut into a rectangular ring shape can be used. The lead 3 in the figure is provided with welded portions 3A that are welded to the electrode surfaces of the battery cells 1 at the four corners of the rectangle. The lead 3 is formed by welding the negative electrode of the battery cell 1 to the upper two welded portions 3A and the positive electrode of the battery cell 1 to the lower two welded portions 3A in the figure, 4 battery cells 1 are connected in two rows and two in a straight line.

[Separator 4]
As shown in FIGS. 4 to 6, the separator 4 is disposed between the battery cell rows 2 arranged adjacent to each other, and prevents heat propagation between the adjacent battery cell rows 2. The separator 4 is made of a heat insulating member so as to prevent heat propagation of the battery cell 1 that generates heat. Further, the separator 4 is made of an insulating material in order to insulate adjacent batteries from each other. Therefore, the separator 4 is manufactured with a member having excellent heat resistance, heat insulation, and insulation, for example, a heat resistant material such as heat resistant plastic or glass. The separator 4 is preferably made of a light and inexpensive resin. The separator 4 is manufactured by molding a plastic such as polypropylene, polyurethane, or polycarbonate (PC) having a low thermal conductivity (preferably 0.5 W / m or less).

  The separator 4 functions not only as insulation of the battery cell 1 but also as a partition wall that prevents propagation of abnormal heat generation. Specifically, the separator 4 is arranged across the battery end portions of the battery cells 1 adjacent to each other in the longitudinal direction so as to straddle the electrode connection surface 9 between the battery cell rows 2. To do. As a result, as shown in FIG. 6, even if one battery cell 1 is abnormally heated and flammable gas leaking from the opened safety valve 5 is ignited, the battery cell array 2 arranged adjacent to each other is separated by the separator 4. Heat insulation can be used to block the propagation of high-temperature gas (flame) and avoid conduction of intense heat. That is, it is possible to effectively prevent the thermal chain when one battery cell 1 reaches a so-called thermal runaway. As shown in FIG. 6, this structure is effective even when the separator 104 having the same length as the conventional one shown in FIG. 21 is used by being offset so as to straddle the electrode connecting surface 9. Can be prevented and safety can be improved. For this reason, it can be set as the battery pack which improved safety | security cheaply, without increasing a number of parts and cost compared with the past.

  As shown in FIGS. 3 and 5, the separator 4 may be individually arranged for each electrode connection surface 9, and although not shown, the separator is extended in the length direction of the battery cell row, so that one separator It can also be configured to insulate over a plurality of electrode connection surfaces 9.

  As shown in FIGS. 2 to 5, the separator 4 is a plate having a narrow width and can reduce the outer shape of the entire battery pack. Furthermore, as shown in FIG. 4, the separator 4 has a height (H) that is substantially the same as or larger than the diameter of the battery cell 1 so that the upper and lower ends approach the inner surface of the case 7. ing. This separator 4 can effectively prevent radiant heat and high-temperature gas from propagating from one battery cell 1 to the other adjacent battery cell 1. In particular, the separator 4 in FIG. 4 causes the upper and lower ends of the separator 4 to abut the inner surface of the case 7 in a state where the battery pack 10 is housed in the case 7. This structure can effectively prevent heat generated from the battery cell from being blocked by the separator 4 and transmitted to the adjacent battery cell 1. However, the upper and lower ends of the separator do not necessarily need to be in contact with the inner surface of the case, and only one of the ends, for example, only the upper end where heat easily moves can be brought into contact with the inner wall of the case.

  The above separator 4 has a slit 6 through which the lead 3 is inserted. This is because the separator 4 disposed between the adjacent battery cell rows 2 intersects the lead 3 connecting the electrodes of the adjacent battery cell rows 2. Accordingly, the slit 6 is opened at an intersection with the electrode connection surface 9 where the lead 3 is disposed. The separator 4 shown in the figure is an intersecting portion with the electrode connection surface 9 and is positioned on the lower side to open a slit 6. Thus, the slit 6 opened downward can reduce heating of the battery cell 1 of the battery cell row 2 adjacent to the hot gas through the slit 6. This is because the main hot gas has the property of moving upward. Furthermore, the slit 6 opened in the separator 4 is narrowed in order to effectively prevent heat such as a hot gas from moving. The slit 6 preferably has such a width that no gap is formed when the lead 3 is inserted. However, the slit can be filled with an adhesive or a caulking agent after the lead is passed through to fill the gap. This structure can effectively prevent the movement of the hot gas while widening the slit and easily inserting the lead.

  Furthermore, as shown in FIG. 8, the separator 24 may be integrated with the case 27. Since this structure can prevent a gap from being formed in the connecting portion between the separator 24 and the inner surface of the case 27, it is possible to effectively prevent the high-temperature gas from propagating from this portion. In particular, as shown in the figure, the separator 24 formed integrally with the inner surface of the upper case 27A can effectively prevent the movement of heat from the upper part where heat is easily propagated. This structure can effectively prevent the propagation of heat in the battery pack used in a posture in which the vertical position is determined.

  Further, the separator 34 may have the shape shown in FIGS. In the separator 34 shown in these drawings, the contact surface with the battery cell 1 is formed in a curved shape along the side surface of the cylindrical outer tube. The separator 34 shown in FIG. 9 has a shape in which two holding plates 31 that are curved in an arc shape are connected in opposite directions, and has a cross-sectional shape that is X-shaped. The separator 34 has a structure in which the curved surface of the holding plate 31 facing the battery cell 1 is used as a holding groove 32 to hold the battery cell 1 arranged here. As shown in FIG. 9, the holding groove 32 is formed into a groove shape along the surface of the cylindrical outer tube of the battery cell 1. The holding groove 32 contacts the surface of the cylindrical battery cell 1 in a surface contact state and holds the battery cell 1 in a fixed position so as not to be displaced. In the separator 34 shown in FIG. 10, the holding plate 31 is formed in an arc shape along substantially half of the outer periphery of the battery cell 1. As described above, the separator 34 having the holding plate 31 having a shape substantially along the outer periphery of the battery cell 1 is adjacent to the high-temperature gas blown out from the safety valve 5 of one battery cell 1 as shown by an arrow in FIG. Since the path to be propagated to the battery cell 1 in the cell row 2 becomes longer, it is possible to effectively prevent the heat of the thermally runaway battery cell from being conducted to the adjacent battery cell 1. However, the holding plate can also make the part along the outer peripheral surface of a battery below half of the outer periphery of a battery.

  Further, the separator 34 shown in FIG. 10 is provided with a V-shaped vertical groove 37 extending in the axial direction of the battery cell 1 on the back surface of the pair of holding plates 31 forming the holding groove 32. As described above, the separator 34 having the vertical groove 37 on the back surface of the holding plate 31 has a hollow air layer 38 between the vertical groove 37 formed above and below the separator 34 and the inner surface of the case 7 as shown in FIG. Therefore, there is an advantage that heat transfer between adjacent battery cell rows 2 can be more effectively prevented. Further, the separator 34 having this shape can be provided with a lead wire or the like in a space formed by the vertical grooves 37. Since this space becomes a space insulated from the battery cell 1 by the separator 34, it can arrange | position, insulating a lead wire from a battery.

  As shown in FIG. 11, the battery pack 30 including the separator 34 illustrated in FIG. 9 can connect the four battery cells 1 adjacent in the axial direction and the column direction in series and in parallel via the strip-shaped leads 33. The separator 34 is welded to the electrode of the battery cell 1 inserted into the pair of holding grooves 32 in a state where the strip-shaped leads 33 are inserted into the slits 36, and then welded to both sides of the welded portion 33 </ b> A provided at the center portion of the leads 33. Welded portions 33 </ b> A located at both ends of the lead 33 are welded to the electrodes of the arranged battery cell 1. Thereafter, the battery cells 1 located on both sides are folded back 180 degrees and stored in the holding grooves 32.

  The battery pack 10 shown in FIGS. 1 to 5 has output leads 8 connected to electrodes at both ends of a plurality of battery cell rows 2 arranged in parallel to each other. The battery cells 1 constituting the battery cell array 2 are directed in the same direction and have output leads 8 connected to the electrodes at both ends. In the battery cell rows 2 connected in parallel to each other, facing electrodes are connected by output leads 8 with the direction of the battery cells 1 being the same direction. The output leads 8 connected to both ends of the battery cell row 2 connect the two battery cells 1 located at both ends of the battery cell row 2 in parallel.

  Furthermore, the battery pack 10 shown in the drawing incorporates a circuit board 11 on which a battery protection circuit is mounted in a case 7. As shown in FIGS. 2, 3, and 5, the battery pack 10 has a circuit board 11 connected to the battery cell 1 via the lead 3 and the output lead 8 and is housed in the case 7 as the battery pack 10. . The output leads 8 connected to both ends of the battery cell array 2 are connected to the circuit board 11, and the leads 3 connecting the battery cells 1 in series are connected to the circuit board 11 as leads for voltage detection. Yes. The circuit board 11 is a board in which electronic components are mounted on an insulating board, and a protection circuit for detecting the battery voltage of the battery cells 1 connected in parallel and controlling the charge / discharge current of the battery cells is mounted. The battery pack is charged and discharged while preventing overcharging and overdischarging of the battery cell 1 with a protection circuit. Further, the protection circuit can also detect charging and discharging of the battery cell 1 by detecting an overcurrent of the battery cell 1.

(Embodiment 2)
A battery pack 40 according to Embodiment 2 of the present invention is shown in FIG. In the battery pack 40 shown in this figure, the separator 44 is formed so that the cross-sectional shape is substantially cross-shaped, and is disposed so as to be interposed between adjacent battery cell rows 2 and on the electrode connection surface 9. . As shown in FIGS. 12 and 13, the separator 44 is a cell disposed between the inter-row plate portion 42 disposed between the adjacent battery cell rows 2 and the battery cell 1 adjacent in the axial direction. The intermediate plate portion 41 is formed into a shape that intersects each other. The inter-row plate portion 42 is disposed on a boundary surface between the adjacent battery cell rows 2 and prevents heat from being propagated between the adjacent battery cell rows 2. In addition, the inter-cell plate portion 41 is disposed on the electrode connection surface 9 of the adjacent battery cell 1 and prevents heat from being transmitted between the adjacent battery cells 1. Therefore, the separator 44 having this structure can achieve both heat insulation at the boundary surface between the battery cell rows 2 and the electrode connection surface 9 of the battery cell 1 constituting the battery cell row 2, and more effectively Propagation can be prevented.

  A battery pack 40 shown in FIG. 12 connects four battery cells 1 adjacent to each other in the axial direction and the column direction via leads 43 beyond the inter-plate plate portion 42 and the inter-cell plate portion 41. The lead 43 is U-bent so as to sandwich both surfaces of the inter-cell plate portion 41 and connects the battery cells 1 adjacent in the axial direction in series. Further, the inter-row plate portion 42 has a slit 46 through which the lead 43 connecting the battery cells 1 of the adjacent battery cell rows 2 is inserted. The inter-row plate portion 42 is located on both surfaces of the inter-cell plate portion 41 and opens two rows of slits 46, and the U-curved lead 43 is inserted so as to sandwich both surfaces of the inter-cell plate portion 41. Yes.

(Embodiment 3)
A battery pack 50 according to Embodiment 3 of the present invention is shown in FIG. In the battery pack shown in this figure, two battery cell rows 2 are arranged in parallel, and the electrode connection surfaces 9 of adjacent battery cell rows 2 are made substantially the same plane so as to be interposed in the electrode connection surface 9. A separator 54 is disposed on the surface. However, the battery pack may have one or three or more battery cell rows. The separator 54 is disposed in a posture that is orthogonal to the longitudinal direction of the battery cell row 2. As shown in FIG. 15, the battery pack 50 has a separator 54 in a plate shape and U-shaped leads 53 so as to sandwich both surfaces of the plate-like separator 54, so that the battery cells 1 adjacent in the axial direction are arranged. They are linked together. Furthermore, the lead 53 connects the battery cells 1 of the adjacent battery cell rows 2 to each other on both surfaces of the separator 54. The battery pack 50 shown in this figure can prevent heat conduction in the longitudinal direction of the battery cell row 2 by the separator 54 disposed between the battery cells 1 adjacent in the longitudinal direction.

  Further, as shown in FIG. 16, the height (H) of the separator 54 is substantially the same as or larger than the diameter of the battery cell 1, and the upper and lower ends approach the inner surface of the case 7. I am letting. The separator 54 can effectively prevent radiant heat and high-temperature gas from propagating from the battery cell 1 that has run out of heat to the battery cell 1 adjacent in the axial direction. In particular, the separator 54 of FIG. 16 brings the upper and lower ends of the separator 54 into contact with the inner surface of the case 7 in a state where the battery pack 50 is housed in the case 7. This structure can effectively prevent the heat generated by the battery cell 1 from being blocked by the separator 54 and transmitted to the adjacent battery cell 1. However, the upper and lower ends of the separator do not necessarily need to be in contact with the inner surface of the case, and only one of the ends, for example, only the upper end where heat easily moves can be brought into contact with the inner wall of the case. Although not shown, this separator can also be formed integrally with the case.

(Embodiment 4)
A battery pack 60 according to Embodiment 4 of the present invention is shown in FIG. In the battery pack 60 shown in this figure, a plurality of battery cell rows 2 are arranged in parallel with each other, but the adjacent battery cell rows are arranged so that the electrode connection surfaces 9 of the adjacent battery cell rows 2 are not substantially on the same plane. 2 is offset. That is, the electrode connection surfaces 9 of the battery cell rows 2 adjacent to each other are arranged at different positions. As shown in the figure, in the battery pack 60 having this structure, even if one battery cell 1 is thermally runaway and high-temperature gas is generated from the safety valve 5 of this battery cell 1, an adjacent battery cell is located at this position. The electrode connection surface 9 of the row 2 is not located. For this reason, the hot gas of the battery cell 1 that has run out of heat is prevented from directly heating the vicinity of the safety valve 5 of the adjacent battery cell 1, and the ejection of the flammable gas due to the breakdown of the safety valve 5, or the flammable gas Is effectively prevented from igniting. The battery pack 60 having this structure can prevent heat from being propagated beyond the battery cell rows by an extremely simple configuration in which the adjacent battery cell rows 2 are offset, and can improve safety and reliability. .

(Embodiment 5)
A battery pack 70 according to Embodiment 5 of the present invention is shown in FIG. In the battery pack 70 shown in this figure, a plurality of battery cell rows 2 are arranged in parallel with each other, and the electrode connection surfaces 9 of the adjacent battery cell rows 2 are substantially the same plane, but are arranged adjacent to each other. The battery cell rows 2 are arranged such that the positive and negative electrode surfaces of the battery cells 1 are opposite to each other. According to this configuration, as shown in the figure, the electrode surface provided with the safety valve 5 is reversed between adjacent battery cell rows 2, so that the combustible gas released from the safety valve 5 of the battery cell 1 that has been thermally runaway is generated. Even if there is ignition, the safety valve 5 is not provided in the battery cell 1 of the adjacent battery cell row 2, so that the risk that the safety valve 5 is opened and further gas is ignited can be reduced. In this battery pack 70, the battery cells 1 constituting each battery cell row 2 are connected in series by leads 73, but the battery cells 1 of the battery cell rows 2 adjacent to each other are not connected by leads 73. In the battery pack 70 of this arrangement, adjacent battery cell arrays 2 arranged in opposite directions are connected in series at the end faces. However, a plurality of battery cells can be connected in parallel.

(Embodiment 6)
Furthermore, a battery pack 80 according to Embodiment 6 of the present invention is shown in FIG. In this battery pack 80, a plurality of battery cells 1 are arranged in the same arrangement as the battery pack shown in FIG. 18, and a separator 84 is arranged so as to be interposed on the electrode connection surface 9. In the battery pack 80 having this structure, in the battery cells 1 adjacent to each other in the battery cell row 2 adjacent to each other, the positions of the safety valves 5 are opposite to each other. Propagation to adjacent battery cells 1 can be prevented, and heat propagation between adjacent battery cells 1 in the axial direction is blocked by the separator 84 disposed on the electrode connection surface 9, thus preventing thermal runaway more reliably. it can.

(Embodiment 7)
A battery pack according to Embodiment 7 of the present invention is shown in FIG. The battery pack 90 shown in this figure is configured by only the battery cells 91 and 91 ′ in which the safety valve 5 is provided on either the positive electrode side or the negative electrode side in one battery cell row 2. ing. Furthermore, a plurality of battery cell rows 92, 92 ′ are arranged in parallel with each other, and the electrode connection surfaces 9 of the adjacent battery cell rows 92, 92 ′ are set to be substantially the same plane. The battery cells 91 and 91 'are arranged so that the electrode surfaces provided with the safety valve 95 are opposite to each other between the battery cell rows 92 and 92' arranged adjacent to each other. That is, the battery pack 90 is provided with a safety valve 95 for releasing the gas inside the outer can on the positive electrode side of the battery cell 91 for the battery cell row 92 positioned on the upper side in the figure, As for the battery cell row 92 ′ located in the battery cell 1 ′, a safety valve 95 for releasing the gas inside the outer can to the outside is provided on the negative electrode surface side of the battery cell 1 ′. According to this configuration, since the electrode surface provided with the safety valve 95 is reversed between the adjacent battery cell rows 92 and 92 ′, the adjacent battery cell may be ignited even if the gas released from the safety valve 95 is ignited. Since the rows 92 and 92 ′ are not provided with the safety valve 95, it is possible to reduce the possibility that the safety valve 95 is opened and the gas is ignited.

  In this battery pack 90, the opposing electrode surfaces of the battery cells 91, 91 ′ constituting each battery cell row 92, 92 ′ are connected in series by leads 93 on the electrode connection surface 9, and the battery cell rows 92 adjacent to each other are connected. , 92 ′ are connected in parallel by leads 93 on the electrode connection surface 9. Furthermore, although this battery pack is not shown, a separator can be disposed so as to be interposed on the electrode connection surface. In the battery pack having this structure, the adjacent battery cells in the battery cell rows adjacent to each other have the safety valves positioned in opposite directions, so that the heat generated by the thermal runaway battery cells is generated in the battery cells adjacent in the row direction. Propagation can be prevented, and heat propagation between battery cells adjacent in the axial direction can be prevented by a separator disposed on the electrode connection surface, so that thermal runaway can be prevented more reliably.

  The battery pack of the present invention can be used safely for portable devices such as a notebook computer, effectively preventing the diffusion of some of the battery cells even if some of the battery cells generate abnormal heat.

1 is a perspective view of a battery pack according to Embodiment 1 of the present invention. It is a disassembled perspective view of the battery pack shown in FIG. FIG. 3 is an exploded perspective view of the battery pack shown in FIG. 2. It is AA sectional view taken on the line of the battery pack shown in FIG. FIG. 3 is a plan view showing an arrangement of battery cells of the battery pack shown in FIG. 2. It is a schematic plan view which shows the example of arrangement | positioning of the battery cell and separator in the battery pack shown in FIG. It is a top view which shows the state which connects a lead | read | reed to a battery cell. It is sectional drawing which shows another example of a separator. It is a bottom perspective view showing another example of a separator. It is a cross-sectional view of a battery pack provided with the separator shown in FIG. FIG. 10 is a bottom perspective view illustrating a state where battery cells are coupled to the separator illustrated in FIG. 9. It is a schematic plan view which shows the example of arrangement | positioning of the battery cell and separator in the battery pack which concerns on Embodiment 2 of this invention. FIG. 13 is a bottom perspective view showing a connection state between battery cells and leads in the battery pack shown in FIG. 12. It is a schematic plan view which shows the example of arrangement | positioning of the battery cell and separator in the battery pack which concerns on Embodiment 3 of this invention. It is a bottom perspective view which shows the connection state of the battery cell and lead | read | reed in the battery pack shown in FIG. It is a longitudinal cross-sectional view of the battery pack shown in FIG. It is a schematic plan view which shows the example of arrangement | positioning of the battery cell in the battery pack which concerns on Embodiment 4 of this invention. It is a schematic plan view which shows the example of arrangement | positioning of the battery cell in the battery pack which concerns on Embodiment 5 of this invention. It is a schematic plan view which shows the example of arrangement | positioning of the battery cell and separator in the battery pack which concerns on Embodiment 6 of this invention. It is a schematic plan view which shows the example of arrangement | positioning of the battery cell in the battery pack which concerns on Embodiment 7 of this invention. It is a schematic plan view which shows the example of arrangement | positioning of the battery cell and separator in the conventional battery pack. It is a schematic plan view which shows a mode that the one battery cell of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery cell 2 ... Battery cell row 3 ... Lead 3A ... Welding part 4 ... Separator 5 ... Safety valve 6 ... Slit 7 ... Case 8 ... Output lead 9 ... Electrode connection surface 10 ... Battery pack 11 ... Circuit board 24 ... Separator 27 ... Case 27A ... Upper case 30 ... Battery pack 31 ... Holding plate 32 ... Holding groove 33 ... Lead 33A ... Welded portion 34 ... Separator 36 ... Slit 37 ... Vertical groove 38 ... Air layer 40 ... Battery pack 41 ... Inter-cell plate portion 42 ... Inter-row plate portion 43 ... Lead 44 ... Separator 46 ... Slit 50 ... Battery pack 53 ... Lead 54 ... Separator 60 ... Battery pack 70 ... Battery pack 73 ... Lead 80 ... Battery pack 84 ... Separator 90 ... Battery pack 91 ... Battery cell 91 '... Battery cell 92 ... Battery cell row 92' ... Battery cell row 93 ... Lead 95 ... Low All valves 101 ... battery cells 102 ... battery cell rows 104 ... separators 105 ... safety valves

Claims (7)

A battery pack in which a plurality of battery cells are connected in series and / or in parallel,
A plurality of battery cells each housed in a cylindrical outer can and having positive and negative electrodes exposed on opposite end faces;
A lead having electrical conductivity for electrically connecting the battery cells;
One or more separators having insulation and heat insulation interposed between the battery cells;
With
The plurality of battery cells are connected to each other by an electrode connecting surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a battery cell row, and the battery cell rows are substantially parallel to the longitudinal direction of the outer can. The electrode connection surfaces of adjacent battery cell rows are arranged substantially in the same plane, and the battery cells are electrically connected at the electrode connection surface via the leads,
The separator is arranged between the battery cell rows so as to intersect the electrode connection surface,
The separator is formed by opening a slit for inserting the lead. The battery pack according to claim 1,
The battery cell is provided with a safety valve on the positive electrode side which is opened when the internal pressure of the outer can becomes higher than a predetermined value and discharges gas inside the outer can to the outside. The battery pack according to claim 1 or 2,
The battery pack is characterized in that the separator further has a substantially cross-shaped cross section and is disposed between adjacent battery cell rows and on an electrode connection surface. A battery pack in which a plurality of battery cells are connected in series and / or in parallel,
A plurality of battery cells each housed in a cylindrical outer can and having positive and negative electrodes exposed on opposite end faces;
A lead having electrical conductivity for electrically connecting the battery cells;
One or more separators having insulation and heat insulation interposed between the battery cells;
With
The plurality of battery cells are connected to each other by an electrode connecting surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a battery cell row, and the battery cell rows are substantially parallel to the longitudinal direction of the outer can. The electrode connection surfaces of adjacent battery cell rows are arranged substantially in the same plane, and the battery cells are electrically connected at the electrode connection surface via the leads,
The separator is disposed so as to be orthogonal to the longitudinal direction of the battery cell row and interposed in the electrode connection surface,
The battery pack is characterized in that the lead is U-bent so as to sandwich both surfaces of the separator and connects the battery cells. A battery pack in which a plurality of battery cells are connected in series and / or in parallel,
A plurality of battery cells each housed in a cylindrical outer can and having positive and negative electrodes exposed on opposite end faces;
With
The plurality of battery cells are connected to each other by an electrode connecting surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a battery cell row, and the battery cell rows are substantially parallel to the longitudinal direction of the outer can. A battery pack, wherein a plurality of adjacent battery cell rows are arranged in an offset manner so that electrode connecting surfaces of adjacent battery cell rows are not substantially coplanar. A battery pack in which a plurality of battery cells are connected in series and / or in parallel,
A plurality of battery cells each housed in a cylindrical outer can and having positive and negative electrodes exposed on opposite end faces;
With
The battery cell is opened when the internal pressure of the outer can becomes higher than a predetermined value, and a safety valve that releases the gas inside the outer can to the outside is provided on either the positive electrode side or the negative electrode side,
The plurality of battery cells are connected to each other by an electrode connecting surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a battery cell row, and the battery cell rows are substantially parallel to the longitudinal direction of the outer can. The electrode connection surfaces of adjacent battery cell rows are arranged substantially in the same plane, and the battery cells are electrically connected at the electrode connection surface via the leads,
The battery pack, wherein the battery cell rows are adjacent battery cell rows, and the battery cells are arranged such that the positive electrode surface and the negative electrode surface of the battery cells are opposite to each other. A battery pack in which a plurality of battery cells are connected in series and / or in parallel,
A plurality of battery cells each housed in a cylindrical outer can and having positive and negative electrodes exposed on opposite end faces;
With
The battery cell is opened when the internal pressure of the outer can becomes higher than a predetermined value, and a safety valve that releases the gas inside the outer can to the outside is provided on either the positive electrode side or the negative electrode side,
The plurality of battery cells are connected to each other by an electrode connection surface in which the positive electrode surface and the negative electrode surface are opposed to each other in the longitudinal direction of the outer can, thereby forming a battery cell array. In the battery cell array, the safety valve is connected to the positive electrode surface. The battery cell row is composed only of the battery cells provided on the same surface side of either the side or the negative electrode surface side, and the connected battery cell rows are arranged in a plurality substantially parallel to the longitudinal direction of the outer can, The electrode connection surfaces of adjacent battery cell rows are substantially the same plane, and the battery cells are electrically connected at the electrode connection surface via the leads,
The battery pack, wherein the battery cell rows are arranged between adjacent battery cell rows so that electrode surfaces provided with safety valves are opposite to each other.

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