Battery Pack

Abstract

The battery pack (1) comprises: a battery group, wherein six batteries (11) having a cylindrical shape and having electrode terminals at the ends on the +Z direction side and the -Z direction side in the cylinder axis direction are arranged along the X-axis direction with the cylinder axes parallel to each other; and tabs (121, 131) connecting the electrode terminals on the +Z direction side of each of the six batteries. Furthermore, when the three batteries (11) arranged along the X-axis direction are arranged as the first battery, the second battery, and the third battery in their arrangement order, the tab (121) is not connected to the second battery, but is connected to the first battery and the third battery.

Description

Technical Field

[0001] The invention relates to a battery pack. Background Art

[0002] A battery pack is proposed, which includes: a battery block assembly, which is formed by arranging a plurality of cylindrical secondary batteries vertically and horizontally, the plurality of cylindrical secondary batteries are in a posture perpendicular to a specific surface of the shell, and the adjacent secondary batteries are arranged in a stacked state; and a storage shell, which accommodates the battery block assembly (for example, refer to patent document 1). The battery pack also includes a lead plate, which is commonly connected to the power of the plurality of secondary batteries constituting the battery block assembly, and connects the plurality of secondary batteries in parallel. The battery pack is cylindrical in a limited space within the storage shell, and the secondary batteries adjacent to each other are arranged in a stacked state. As a result, even if the battery pack falls to the ground or an external force is applied to the battery pack due to a collision between the battery packs arranged adjacent to each other, the secondary battery can be suppressed from breaking and a safe state can be maintained.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-317458 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, in the battery pack described in Patent Document 1, since a plurality of secondary batteries are arranged in a stacked state in a limited space within a storage case, adjacent secondary batteries are close to each other. Therefore, in the event of a fire in a secondary battery, since the batteries are arranged in a limited space, the heat transferred through the lead plate and the heat transferred through the air existing in the gaps between the secondary batteries are concentrated on the secondary battery close to the battery that caught fire. As a result, the secondary battery close to the secondary battery that caught fire first is heated to a high temperature, and as a result, a secondary fire may be caused.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery pack that can suppress the spread of fire to other batteries when one of a plurality of batteries arranged in a predetermined space catches fire.

[0009] Means used to solve problems

[0010] In order to achieve the above-mentioned object, the battery pack of the present invention has:

[0011] A battery pack, wherein a plurality of batteries having a cylindrical outer shape and having electrode terminals at the positive and negative ends in the cylindrical axis direction are arranged along a first direction orthogonal to the cylindrical axis direction with the cylindrical axes parallel to each other; and

[0012] a tab that connects the electrode terminals at the ends of the positive sides of the respective batteries,

[0013] The plurality of batteries include the first battery, the second battery, and the third battery arranged in the order of a first battery, a second battery, and a third battery,

[0014] The tab includes a first tab that is not connected to the second battery but is connected to the first battery and the third battery.

[0015] In addition, the battery pack of the present invention may also be:

[0016] The plurality of batteries include a fourth battery, the fourth battery being adjacent to a side of the third battery opposite to the second battery side and not connected to the first tab,

[0017] The tabs include a second tab,

[0018] The second electrode tab is not connected to the first battery and the third battery, but is connected to the second battery and the fourth battery.

[0019] In addition, the battery pack of the present invention may also be:

[0020] When viewed from the positive side in the cylindrical axis direction, the first electrode tab intersects with the second electrode tab at at least one location.

[0021] In addition, the battery pack of the present invention may also be:

[0022] When viewed in plan from a second direction perpendicular to the cylinder axis direction and the first direction, the first electrode tab intersects the second electrode tab at at least one location.

[0023] In addition, the battery pack of the present invention may also be:

[0024] The plurality of batteries further include a fifth battery adjacent to the first battery in the second direction, a sixth battery adjacent to the second battery in the second direction, a seventh battery adjacent to the third battery in the second direction, and an eighth battery adjacent to the fourth battery in the second direction.

[0025] The first electrode tab is not connected to the fifth battery and the seventh battery, but is connected to the sixth battery and the eighth battery.

[0026] The second electrode tab is not connected to the sixth battery and the eighth battery, but is connected to the fifth battery and the seventh battery.

[0027] In addition, the battery pack of the present invention may also be:

[0028] A positive terminal is provided at the positive end of the first battery and the second battery in the cylinder axis direction.

[0029] Negative terminals are provided at the ends of the third battery and the fourth battery on the positive side in the cylinder axis direction.

[0030] In addition, the battery pack of the present invention may also be:

[0031] The pole tab has a plurality of sub-pole tabs.

[0032] Effects of the Invention

[0033] According to the present invention, the first battery, the second battery, and the third battery are arranged in the order of the first battery, the second battery, and the third battery, and the first electrode tab is not connected to the second battery, but is connected to the first battery and the third battery. Thus, when one of the multiple batteries catches fire, heat is prevented from being concentratedly transferred to other batteries adjacent to the battery that has caught fire. Therefore, the spread of fire to other batteries caused by heating other batteries adjacent to the battery that has caught fire to a high temperature is prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a perspective view of the battery pack according to the first embodiment of the present invention.

[0035] Figure 2A It is a top view of the battery pack according to the first embodiment.

[0036] Figure 2B This is a side view of the battery pack according to Embodiment 1.

[0037] Figure 3 This is a circuit diagram of the battery pack according to the first embodiment.

[0038] Figure 4A It is a top view of a battery pack of a comparative example.

[0039] Figure 4B It is a diagram for explaining the function of a battery pack of a comparative example.

[0040] Figure 5A It is a partial top view of the battery pack according to the first embodiment.

[0041] Figure 5B This is a diagram for explaining the function of the battery pack according to the first embodiment.

[0042] Fig. 6AIt is a plan view of a battery pack according to Embodiment 2 of the present invention.

[0043] Figure 6B It is a side view of the battery pack according to the second embodiment.

[0044] Fig. 7A It is a plan view of a battery pack according to a third embodiment of the present invention.

[0045] Figure 7B It is a plan view of a battery pack according to a modified example of the third embodiment.

[0046] Figure 8 It is a perspective view of a battery pack according to a fourth embodiment of the present invention.

[0047] Fig. 9A It is a top view of the battery pack according to the fourth embodiment.

[0048] Fig. 9B It is a side view of the battery pack according to the fourth embodiment.

[0049] Fig. 10A It is a top view of a battery pack according to a modified example.

[0050] Fig. 10B It is a side view of a battery pack according to a modified example.

[0051] Fig.11 It is a perspective view of a battery pack according to a modified example.

[0052] Fig.12 It is a perspective view of a battery pack according to a modified example.

[0053] Fig.13 It is a perspective view of a battery pack according to a modified example.

[0054] Fig.14A : is a circuit diagram showing an equivalent circuit of a battery pack according to a modification.

[0055] Fig. 14B : is a circuit diagram showing an equivalent circuit of a battery pack according to a modification.

[0056] Fig.15 It is a perspective view of a battery pack according to a modified example. DETAILED DESCRIPTION

[0057] (Implementation Method 1)

[0058] The embodiment of the present invention is described in detail below with reference to the accompanying drawings. The battery pack of this embodiment comprises: a first battery group including three or more batteries that are cylindrical and arranged in one direction with the cylinder axis direction parallel to each other; and at least one tab that connects the electrode terminal of any one of the three or more batteries to the electrode terminal of a battery other than the other batteries that are adjacent to the one battery in one direction.

[0059] like Figure 1 , Figure 2A and Figure 2B As shown, the battery pack 1 of this embodiment comprises: a battery group, which includes six batteries 11 arranged along a first direction orthogonal to the cylinder axis direction, i.e., the X-axis direction, with their cylinder axes parallel to each other; pole tabs 121, 122, 131, 132, 171, 172, 181, 182; and printed circuit boards (hereinafter referred to as "PCB") 15, 16.

[0060] The battery 11 is, for example, a rechargeable secondary battery. As the secondary battery, a lithium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, etc. can be used. The six batteries 11 are so-called cylindrical batteries having a cylindrical shape, and have electrode terminals at the positive side in the direction of the cylinder axis J1, that is, the end on the +Z direction side, and the negative side, that is, the end on the -Z direction side. That is, the battery 11 has a positive terminal 11a as an electrode terminal provided at one end in the direction of the cylinder axis J1, and a negative terminal 11b as an electrode terminal provided at the other end in the direction of the cylinder axis J1. In addition, the six batteries 11 are arranged in a straight line along the X-axis direction in a posture parallel to each other in the direction of the cylinder axis J1. In addition, as Figure 2A As shown, the six batteries 11 are arranged at equal intervals so that the shortest distance between adjacent batteries 11 is a distance W2. In addition, the distance between the cylinder axes J1 of the six batteries 11 is fixed at a distance W1.

[0061] In addition, the six batteries 11 include: a first battery group 1A including two batteries 11 arranged in a posture that the direction from the positive terminal 11a toward the negative terminal 11b along the cylinder axis J1 direction coincides with the -Z direction; and a second battery group 1B including two batteries 11 arranged in a posture that the direction from the positive terminal 11a toward the negative terminal 11b along the cylinder axis J1 direction coincides with the positive direction in the cylinder axis J1 direction, that is, the +Z direction. Furthermore, the two first battery groups 1A and the one second battery group 1B are alternately arranged along the X-axis direction.

[0062] The tabs 121, 122, 131, 132, 171, 172, 181, 182 are respectively formed of metal plates such as Cu and Al. Figure 2A and Figure 2BAs shown, the width W3 of each of the tabs 121, 122, 131, 132, 171, 172, 181, 182 in the direction orthogonal to the extension direction and the thickness direction is the same. Here, the tabs 121, 122, 131, 132 connect the electrode terminals at the ends of the positive side, i.e., the +Z direction side, of each of the six batteries 11. One end of each of the tabs 122 and 132 is fixed to the PCB 15, and they are electrically connected to each other via the conductive pattern 151 formed on the PCB 15. In addition, the tab 122 is electrically connected to the positive terminal 11a of the second battery 11 in the -X direction from the battery 11 arranged closest to the +X direction side. In addition, the tab 132 is electrically connected to the positive terminal 11a of the battery 11 arranged closest to the +X direction side. It should be noted that the tabs 122 and 132 can also be electrically connected to each other via the conductive pattern 151 formed on the PCB 15. The tab 121 electrically connects the positive terminal 11a of the battery 11 disposed most on the -X direction side to the negative terminal 11b of the battery 11 disposed third from the -X direction side. The tab 131 electrically connects the positive terminal 11a of the battery 11 disposed second from the battery 11 disposed most on the -X direction side in the +X direction to the negative terminal 11b of the battery 11 disposed fourth from the battery 11 disposed most on the -X direction side in the +X direction. That is, the tabs 121 and 131 connect the positive terminal 11a of any one of the six batteries 11 to the negative terminal 11b of the battery 11 other than the battery 11 adjacent to the one battery 11 in the X-axis direction. In addition, when the battery 11 disposed closest to the -X direction side is set as the first battery, the battery 11 adjacent to the first battery on the +X direction side is set as the second battery, and the battery 11 adjacent to the second battery on the +X direction side is set as the third battery, the tab 121 is not connected to the second battery, but is connected to the first battery and the third battery. In addition, when the battery 11 adjacent to the +X direction side on the side opposite to the second battery side in the third battery is set as the fourth battery, the tab 131 is not connected to the first battery and the third battery, but is connected to the second battery and the fourth battery. The tabs 121, 122, 131, 132 are welded to the positive terminal 11a and the negative terminal 11b of the battery 11 by resistance spot welding, laser spot welding, etc.

[0063] One end of each of the tabs 172 and 182 is fixed to the PCB 15, and is electrically connected to each other via the conductive pattern 161 formed on the PCB 15. In addition, the tab 172 is electrically connected to the negative terminal 11b of the battery 11 arranged most on the -X direction side. In addition, the tab 182 is electrically connected to the negative terminal 11b of the battery 11 arranged second in the +X direction from the battery 11 arranged most on the -X direction side. The tab 171 electrically connects the positive terminal 11a of the battery 11 arranged third in the +X direction from the battery 11 arranged most on the -X direction side to the negative terminal 11b of the battery 11 arranged fifth in the +X direction from the battery 11 arranged most on the -X direction side. The tab 181 electrically connects the negative terminal 11b of the battery 11 arranged most on the +X direction side to the positive terminal 11a of the battery 11 arranged third in the -X direction from the battery 11 arranged most on the +X direction side. That is, the tabs 171 and 181 connect the positive terminal 11a of any one of the six batteries 11 to the negative terminal 11b of the battery 11 other than the battery 11 adjacent to the one battery 11 in the X-axis direction. The tabs 171, 172, 181, and 182 are welded to the positive terminal 11a and the negative terminal 11b of the battery 11 by resistance spot welding, laser spot welding, etc., respectively. Moreover, the six batteries 11 are connected by the tabs 121, 122, 131, 132, 171, 172, 181, and 182, respectively. Figure 3 As shown, they are connected between the conductive patterns 151 and 161 of the PCB 15 in a two-parallel and three-series manner.

[0064] Here, the function of the battery pack 1 of this embodiment will be described in comparison with the comparative example. Figure 4A As shown in FIG. 1 , the battery pack of the comparative example includes tabs 9012 and 9017 with a width W3 extending in the X-axis direction. In the battery pack of the comparative example, a heat transfer path through the tabs 9012 and 9017 and a heat transfer path through the air between the battery 11A and the battery 11B are formed between the battery 11A and the battery 11B. Here, for example, in the case where the battery 11A catches fire and generates a large amount of heat, Figure 4B As shown by arrow AR91, the heat generated by battery 11A is concentratedly transferred to adjacent battery 11B, so the possibility of battery 11B being heated to an ignition temperature or higher becomes high.

[0065] On the other hand, in the battery pack 1 of the present embodiment, as Figure 5AAs shown, between battery 11A and battery 11B, only a heat transfer path is formed via the air existing between battery 11A and battery 11B, and between battery 11A and battery 11C, a heat transfer path is formed via the pole ears 121, 131, 171, 181 and a heat transfer path is formed via the air existing between battery 11A and battery 11C. Therefore, the thermal resistance between battery 11A and battery 11B is increased compared to the comparative example by the amount that the heat transfer path via the pole ears 121, 131, 171, 181 is not formed. Therefore, the thermal resistance between battery 11A and battery 11B becomes closer to the thermal resistance between battery 11A and battery 11C than the comparative example. Therefore, for example, in the case where battery 11A catches fire and generates a large amount of heat, Figure 5B As shown by the arrow AR11, the amount of heat transferred from the battery 11A to the battery 11B is reduced, while on the other hand, Figure 5B As shown by arrow AR12, the amount of heat transferred from battery 11A to battery 11C increases. As a result, the heat generated by battery 11A is evenly transferred to batteries 11B and 11C, thereby suppressing excessive temperature increases of batteries 11B and 11C.

[0066] As described above, according to the battery pack 1 of the present embodiment, the tabs 121 and 131 connect the positive terminal 11a of any one of the six batteries 11 and the negative terminal 11b of the battery 11 other than the other battery 11 adjacent to the one battery 11 in the X-axis direction. In addition, the tabs 171 and 181 connect the positive terminal 11a of any one of the six batteries 11 and the negative terminal 11b of the battery 11 other than the other battery 11 adjacent to the one battery 11 in the X-axis direction. Thus, in the event that one of the six batteries 11 is on fire, heat is prevented from being concentratedly transferred to the other batteries 11 adjacent to the battery 11 on fire. Therefore, the spread of fire to the other batteries 11 caused by heating the other batteries 11 adjacent to the battery 11 on fire to a high temperature is prevented.

[0067] (Implementation Method 2)

[0068] The battery pack of this embodiment has a different shape of the tabs from the battery pack 1 of Embodiment 1. Specifically, the difference is that one tab intersects one portion of the other tab when viewed from the positive side in the cylinder axis J1 direction, that is, in the +Z direction.

[0069] like Fig. 6A and Figure 6B As shown, the battery pack 2 of this embodiment includes six batteries 11, tabs 2121, 122, 131, 132, 2171, 172, 181, 182, and PCBs 15 and 16. Fig. 6A and Figure 6B In the embodiment 1, the same structures as those in the embodiment 1 are marked with Figure 2A and Figure 2B Same mark.

[0070] When viewed from the positive side in the direction of the cylinder axis J1, that is, the +Z direction, the tab 2121 intersects with a portion of the tab 131. Here, when the tab 131 is set as the second tab of claim 3, the tab 2121 is equivalent to the first tab of claim 3. The tab 2121 is in the shape of a long strip, and both ends in the long side direction are respectively connected to the positive terminal 11a and the negative terminal 11b of the following two batteries 11, which are arranged on both sides of the battery 11 in the X-axis direction to which the tab 131 is connected to the positive terminal 11a. Moreover, the tab 2121 is arranged to straddle the +Z direction side of the positive terminal 11a to which the tab 131 is connected in a state separated from the tab 131. Here, when the tab 2121 is set as the first tab described in claim 3, the tab 131 is equivalent to the second tab described in claim 3. When viewed from the Z-axis direction, the tab 2171 also overlaps with a portion of the tab 181. The tab 2171 is in the shape of a long strip, and the two ends in the long side direction are respectively connected to the positive terminal 11a and the negative terminal 11b of the following two batteries 11, which are arranged on both sides of the X-axis direction of the battery 11 to which the tab 181 is connected at the positive terminal 11a. In addition, the tab 2171 is arranged to straddle the -Z direction side of the positive terminal 11a to which the tab 181 is connected in a state separated from the tab 181.

[0071] According to the battery pack 2 of this embodiment, the tabs 2121 are arranged on the +Z direction side of the six batteries 11, and the tabs 2171 are arranged on the -Z direction side of the six batteries 11. This can reduce the width of the battery pack 2 in the Y-axis direction, and thus achieve a thinner casing of the battery pack 2.

[0072] (Implementation method 3)

[0073] The battery pack of this embodiment is different from the battery pack 1 of the first embodiment in that the cylinder axis of at least one of the three or more batteries is arranged at a position offset in the Y-axis direction from a virtual plane including the cylinder axes of the other batteries and parallel to the X-axis direction.

[0074] like Fig. 7A As shown, the battery pack 3 of this embodiment includes six batteries 11, tabs 3121, 122, 3131, 132, 3171, 3181, 182, and PCBs 15 and 16. Fig. 7A The same structures as those in Implementation 1 are marked with Figure 2AThe same mark. The battery 11 arranged on the side closest to the -X direction among the six batteries 11 and the third and fifth batteries 11 arranged in the +X direction from the battery 11 arranged on the side closest to the -X direction are arranged in a straight line along the X-axis direction. In addition, the second, fourth, and sixth batteries 11 arranged in the +X direction from the battery 11 arranged on the side closest to the -X direction are arranged in a state in which their cylinder axes J1 are arranged at positions offset in the +Y direction from a virtual plane VL3 that includes the cylinder axes J1 of other batteries 11 and is parallel to the X-axis direction. The cylinder axes J1 of the second, fourth, and sixth batteries 11 arranged in the +X direction from the battery 11 arranged on the side closest to the -X direction are arranged at positions offset by a distance W304 from the virtual plane VL3. In addition, if expressed without using a virtual plane, Figure 2A The cylindrical axis J1 and the cylindrical axis J2 of the battery 11 which is arranged first from the left Figure 2A The cylinder axis J1 of the battery 11 arranged third from the left in the figure is arranged on a straight line parallel to the X direction, which is the direction in which the batteries 11 are arranged. Figure 2A The barrel axis J1 of the second battery 11 from the left and Figure 2A The cylinder axis J1 of the battery 11 arranged first from the left is arranged on a straight line that is not parallel to the X direction, which is the direction in which the batteries 11 are arranged. The distance W304 is set to be, for example, a length that is less than the radius of the battery 11 when the battery 11 is viewed from the Z-axis direction. Moreover, the six batteries 11 are arranged so that the shortest distance between each of the batteries 11 arranged at the closest position is the distance W2. Here, the distance W301 between the cylinder axes J1 of two adjacent batteries 11 in the X-axis direction can be shorter than the distance W1 in the battery pack 1 of the first embodiment.

[0075] The tab 3121 electrically connects the positive terminal 11a of the battery 11 disposed most on the -X direction side to the negative terminal 11b of the battery 11 disposed third from the -X direction side. The tab 3131 electrically connects the positive terminal 11a of the battery 11 disposed second in the +Z direction from the battery 11 disposed most on the -X direction side to the negative terminal 11b of the battery 11 disposed fourth in the +X direction from the battery 11 disposed most on the -X direction side. The tab 3171 electrically connects the positive terminal 11a of the battery 11 disposed third in the +X direction from the battery 11 disposed most on the -X direction side to the negative terminal 11b of the battery 11 disposed second in the -X direction from the battery 11 disposed most on the +X direction side. The tab 3181 electrically connects the negative electrode terminal 11 b of the battery 11 disposed most on the +X direction side and the positive electrode terminal 11 a of the battery 11 disposed third in the −X direction from the battery 11 disposed most on the +X direction side.

[0076] It should be noted that it is also possible to Figure 7B As shown in the battery pack 4, the battery pack 4 includes a tab 4121 that is in the shape of an elongated plate and overlaps a portion of the tab 3131 when viewed from the Z-axis direction, and a tab 4171 that is in the shape of an elongated plate and overlaps a portion of the tab 3181 when viewed from the Z-axis direction. Here, the shapes of the tabs 4121 and 4171 may be the same as the tabs 2121 and 2171 described in the second embodiment.

[0077] According to the battery packs 3 and 4 of the present embodiment, the distance W301 between the cylinder axes J1 of two adjacent batteries 11 in the X-axis direction is shorter than the distance W1 in the battery pack 1 of embodiment 1. As a result, the length in the X-axis direction can be shortened compared to the battery pack 1 of embodiment 1, and thus the battery pack 3 can be miniaturized accordingly.

[0078] (Implementation 4)

[0079] The battery pack of this embodiment is different from the battery pack 1 of the first embodiment in that one tab intersects with the other tabs at at least one location when viewed in plan from the Y-axis direction.

[0080] like Figure 8 , Fig. 9A and Fig. 9B As shown, the battery pack 5 of this embodiment includes eight batteries 11, tabs 5121, 5131, 5171, 5172, 5173, 5181, 5182, 5183, and PCBs 15 and 16. Figure 8 , Fig. 9A and Fig. 9B In the embodiment 1, the same structures as those in the embodiment 1 are marked with Figure 1 , Figure 2A and Figure 2B The eight batteries 11 are alternately arranged along the X-axis direction, with two first battery groups 1A and two second battery groups 1B, the two first battery groups 1A including two batteries 11 arranged in a posture that the direction from the positive terminal 11a toward the negative terminal 11b along the cylinder axis J1 direction coincides with the -Z direction, and the two second battery groups 1B including two batteries 11 arranged in a posture that the direction from the positive terminal 11a toward the negative terminal 11b along the cylinder axis J1 direction coincides with the +Z direction as the third direction.

[0081] One of the two tabs 5121 on the -X direction side electrically connects the positive terminal 11a of the battery 11 arranged most on the -X direction side to the negative terminal 11b of the battery 11 arranged third in the +X direction from the battery 11 arranged most on the -X direction side. The other of the two tabs 5121 on the +X direction side electrically connects the positive terminal 11a of the battery 11 arranged fifth in the +X direction from the battery 11 arranged most on the -X direction side to the negative terminal 11b of the battery 11 arranged seventh in the +X direction from the battery 11 arranged most on the -X direction side. One of the two tabs 5131 on the -X direction side electrically connects the positive terminal 11a of the battery 11 arranged second in the +X direction from the battery 11 arranged most on the -X direction side to the negative terminal 11b of the battery 11 arranged fourth in the +X direction from the battery 11 arranged most on the -X direction side. The other of the two tabs 5131 on the +X direction side electrically connects the positive terminal 11a of the battery 11 arranged sixth in the +X direction from the battery 11 arranged closest to the -X direction to the negative terminal 11b of the battery 11 arranged closest to the +X direction. Here, the tab 5121 intersects the tab 5131 at at least one location when viewed from the Y-axis direction, a second direction orthogonal to the barrel axis J1 direction and the first direction, i.e., the X-axis direction. Here, when the tab 5121 is set as the first tab of claim 4, the tab 5131 is equivalent to the second tab of claim 4. In addition, the overlapping portion 5131a of the tab 5131 that overlaps with the tab 5121 is arranged at a position separated from the tab 5121 by a distance W505 in the Y-axis direction.

[0082] like Fig. 9A and Fig. 9B As shown, one end of each of the tabs 5172 and 5182 is fixed to the PCB 15, and they are electrically connected to each other via the conductive pattern 161 formed on the PCB 15. In addition, the tab 5172 is electrically connected to the negative terminal 11b of the battery 11 arranged closest to the -X direction. In addition, the tab 5182 is electrically connected to the negative terminal 11b of the battery 11 arranged closest to the -X direction. In addition, the tab 5182 is electrically connected to the negative terminal 11b of the battery 11 arranged second in the +X direction from the battery 11 arranged closest to the -X direction. One end of each of the tabs 5173 and 5183 is fixed to the PCB 15, and they are electrically connected to each other via the conductive pattern 151 formed on the PCB 15. In addition, the tab 5173 is electrically connected to the positive terminal 11a of the battery 11 arranged closest to the +X direction. In addition, the tab 5183 is electrically connected to the positive terminal 11a of the battery 11 arranged second in the -X direction from the battery 11 arranged closest to the +X direction.

[0083] The tab 5171 electrically connects the positive terminal 11a of the battery 11 arranged third in the +X direction from the battery 11 arranged most on the -X direction side to the negative terminal 11b of the battery 11 arranged fifth in the +X direction from the battery 11 arranged most on the -X direction side. The tab 5181 electrically connects the positive terminal 11a of the battery 11 arranged fourth in the +X direction from the battery 11 arranged most on the -X direction side to the negative terminal 11b of the battery 11 arranged sixth in the +X direction from the battery 11 arranged most on the -X direction side. Here, the tab 5181 overlaps with a portion of the tab 5171 when viewed from the -Y direction. Moreover, the overlapping portion 5181a of the tab 5181 that overlaps with the tab 5171 is arranged at a position separated from the tab 5171 by a distance W505 in the Y-axis direction. In this way, the eight batteries 11 are connected between the conductive patterns 151 and 161 of the PCB 15 in a four-in-series and two-in-parallel manner through the tabs 5121 , 5131 , 5171 , 5172 , 5173 , 5181 , 5182 , and 5183 , respectively.

[0084] According to the battery pack 5 of this embodiment, the tabs 5121 , 5131 , 5171 , 5172 , 5173 , and 5181 can all be arranged on the −Y direction side of the eight batteries 11 , thereby achieving space saving on the +Y direction side of the eight batteries 11 .

[0085] The above describes the various embodiments of the present invention, but the present invention is not limited to the structures of the above-mentioned embodiments. Fig. 10A and Fig. 10B As shown in the battery pack 6, the tabs 2121 and 2171 are connected to the tabs 6131 and 6181 via the connecting portions 6121a and 6171a at the portions overlapping with the tabs 6131 and 6181 when viewed from the Z-axis direction. Fig. 10A and Fig. 10B In the embodiment 1, the same structure is marked with Figure 2A and Figure 2BSame markings. Here, the portion of the tab 6131 connected to the positive terminal 11a of the battery 11 has a shape extending from the positive terminal 11a to the -X direction side. In addition, the portion of the tab 6181 connected to the positive terminal 11a of the battery 11 also has a shape extending from the positive terminal 11a to the -X direction side. That is, the width of the portion of the tabs 6131 and 6181 connected to the positive terminal 11a of the battery 11 in a direction orthogonal to their extension direction and thickness direction is longer than the width of other portions. The joints 6121a and 6171a are formed by resistance spot welding, laser spot welding, etc. In addition, the thermal resistance per unit length of each of the joints 6121a and 6171a is greater than the thermal resistance per unit length of the tabs 2121, 6131, 2171, and 6181.

[0086] Alternatively, you can Fig.11 As shown in the battery pack 7 shown in FIG. 1 , the tabs 5131 and 5181 are respectively connected to the tabs 5121 and 5171 via the connecting portions 7121a and 7171a at the overlapping portions 5131a and 5181a overlapping with the tabs 5121 and 5171 when viewed from the Z-axis direction. Here, the thermal resistance per unit length of the connecting portions 7121a and 7171a is greater than the thermal resistance per unit length of each of the tabs 5121, 5131, 5171, and 5181.

[0087] According to this structure, the electrode tabs 2121 and 2171 are connected to the electrode tabs 6131 and 6181 via the connecting portions 6121 a and 6171 a , respectively, thereby reducing the resistance generated between the electrode tabs 2121 and 2171 and the electrode tabs 6131 and 6181 .

[0088] In the first embodiment, the tabs 121, 122, 131, 132, 171, 172, 181, 182 may each include a plurality of sub-tabs. Fig.12 As shown in the battery pack 8, the tab 8121 includes five sub-tabs 1211, 1212, 1213, and the tab 8131 includes five sub-tabs 1311, 1312, 1313. In addition, the tab 8171 may also include five sub-tabs 1711, 1712, 1713. In addition, the tab 8122 may include three sub-tabs 1221, 1222, 1223, and the tab 8132 may include three sub-tabs 1321, 1322, 1323. In addition, the tab 8172 may include three sub-tabs 1721, 1722, 1723, and the tab 8182 may include three sub-tabs.

[0089] In each embodiment, a structure in which a plurality of batteries 11 are arranged in a straight line along the X-axis direction is described, but the arrangement of the batteries 11 is not limited thereto. Fig.13The battery pack 1001 shown in the figure has a first battery group and a second battery group, the first battery group includes four batteries 11 arranged along the X-axis direction, and the second battery group includes four batteries 11 arranged adjacent to the four batteries 11 on the +Y direction side of the battery group. Fig.13 In the embodiment 1, the same structures as those in the embodiment 1 are marked with Figure 1 The same reference numerals are used. In other words, the first battery group and the second battery group include a battery 11 arranged on the -Y direction side closest to the -X direction side as a first battery, a battery 11 adjacent to the first battery on the +X direction side as a second battery, a battery 11 adjacent to the second battery on the +X direction side as a third battery, a battery 11 adjacent to the third battery on the +X direction side as a fourth battery, a fifth battery adjacent to the first battery on the second direction, i.e., the +Y direction side, a sixth battery adjacent to the second battery on the +Y direction side, a seventh battery adjacent to the third battery on the +Y direction side, and an eighth battery adjacent to the fourth battery on the +Y direction side. The battery pack 1001 includes two first battery groups 101A and two second battery groups 101B, and the first battery groups 101A and the second battery groups 101B are alternately arranged along the X-axis direction. The first battery group 101A includes four batteries 11 arranged in two rows and two columns, two along the X-axis direction and two along the Y-axis direction, with the positive terminal 11a located on the +Z direction side of the battery 11. The second battery group 101B includes four batteries 11 arranged in two rows and two columns, two along the X-axis direction and two along the Y-axis direction, with the positive terminal 11a located on the -Z direction side. In addition, the battery pack 1001 includes tabs 10121, 10131, 10133, 10171, 10181, and a PCB (not shown). One end of each of the tabs 10121 and 10131 is fixed to the PCB and is electrically connected to each other via a conductive pattern (not shown) formed on the PCB 15.

[0090] The tabs 10121 and 10131 intersect at three locations when viewed from the direction of the cylinder axis J1 of each of the eight batteries 11. The tab 10121 has connecting pieces 10121a, 10121b, and 10121d and extension pieces 10121c and 10121h. Here, the connecting piece 10121a connects the positive terminal 11a of the battery 11 arranged on the -Y direction side to the positive terminal 11a of the battery 11 arranged on the +X direction side and the +Y direction side relative to the battery 11. The connecting piece 10121b connects the positive terminal 11a of the battery 11 arranged on the +Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the -Y direction side relative to the battery 11. The connecting piece 10121d connects the negative terminal 11b of the battery 11 arranged on the -Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and on the +Y direction side relative to the battery 11. That is, the tab 10121 is configured to connect each of the eight batteries 11 arranged along the X-axis direction on the -Y direction side to the battery 11 other than the battery 11 whose distance to each of the eight batteries 11 on the -Y direction side is the shortest among the eight batteries 11 adjacent in the +Y direction.

[0091] The extension piece 10121c is continuous with the connection pieces 10121a, 10121b, and 10121d, and connects the positive terminal 11a of the battery 11 arranged on the side closest to the -X direction to the negative terminal 11b of the battery 11 arranged third from the battery 11 arranged on the side closest to the -X direction in the +X direction. That is, the tab 10121 is a first tab that is not connected to the second battery, the fourth battery, the fifth battery, and the seventh battery, but is connected to the first battery, the third battery, the sixth battery, and the eighth battery. In addition, the other extension pieces 10121c are continuous with the connection pieces 10121a, 10121b, and 10121d, and connect the positive terminal 11a of the battery 11 arranged fifth from the side closest to the -X direction to the +X direction to the negative terminal 11b of the battery 11 arranged seventh from the battery 11 arranged on the side closest to the -X direction in the +X direction. The extension piece 10121h extends from the connecting portion of the connecting pieces 10121a and 10121b in the +Y direction, and the front end portion is connected to PCB15.

[0092] The tab 10131 has connecting pieces 10131a, 10131b, 10131d and extension pieces 10131c, 10131h. The connecting piece 10131a connects the positive terminal 11a of the battery 11 arranged on the +Y direction side to the positive terminal 11a of the battery 11 arranged on the +X direction side and the -Y direction side relative to the battery 11. The connecting piece 10131b connects the positive terminal 11a of the battery 11 arranged on the -Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the +Y direction side relative to the battery 11. The connecting piece 10131d connects the negative terminal 11b of the battery 11 arranged on the +Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the -Y direction side relative to the battery 11. That is, the tab 10131 is configured to connect each of the eight batteries 11 arranged along the X-axis direction on the +Y direction side to a battery 11 other than the battery 11 whose distance between each of the eight batteries 11 located on the +Y direction side and the eight batteries 11 adjacent to the -Y direction is the shortest.

[0093] The extension piece 10131c is continuous with the connection pieces 10131a, 10131b, and 10131d, and electrically connects the positive terminal 11a of the second battery 11 arranged in the +X direction from the battery 11 arranged most on the -X direction side to the negative terminal 11b of the fourth battery 11 arranged in the +X direction from the battery 11 arranged most on the -X direction side. That is, the tab 10131 is a second tab that is not connected to the first battery, the third battery, the sixth battery, and the eighth battery, but is connected to the second battery, the fourth battery, the fifth battery, and the seventh battery. The extension piece 10131c, which is different from the above, is continuous with the connection pieces 10131a and 10131b, and electrically connects the positive terminal 11a of the battery 11 arranged sixth in the +X direction from the battery 11 arranged closest to the -X direction with the negative terminal 11b of the battery 11 arranged eighth in the +X direction from the battery 11 arranged closest to the -X direction. The extension piece 10131h extends from the connection portion of the connection pieces 10131b and 10131d in the +Y direction, and the front end portion is connected to the PCB 15.

[0094] It should be noted that the tabs 10171 and 10181 have the same shape as the tabs 10121 and 10131, respectively. The extension piece 10171c of the tab 10171 electrically connects the positive terminal 11a of the battery 11 arranged third in the +X direction from the battery 11 arranged closest to the -X direction to the negative terminal 11b of the battery 11 arranged fifth in the +X direction from the battery 11 arranged closest to the -X direction. The extension piece 10181c of the tab 10181 electrically connects the positive terminal 11a of the battery 11 arranged fourth in the +X direction from the battery 11 arranged closest to the -X direction to the negative terminal 11b of the battery 11 arranged sixth in the +X direction from the battery 11 arranged closest to the -X direction. The tabs 10171 and 10181 are connected to the PCB 15, respectively.

[0095] Here, when the extension pieces 10121h and 10131h on the PCB 15 are not connected to each other via a resistor, the battery pack 1001 is Fig.14A On the other hand, when the extension pieces 10121h and 10131h on PCB 15 are connected to each other via resistor R10, the battery pack 1001 is Fig. 14B The equivalent circuit shown is represented.

[0096] In addition, you can also Fig.15 As shown in the battery pack 1002, the first battery group 111A includes six batteries 11 and the second battery group 111B includes six batteries. Here, the first battery group 111A includes six batteries 11 arranged in the X-axis direction with the positive terminal 11a located on the +Z direction side of the battery 11, three batteries 11 arranged in the Y-axis direction. The second battery group 111B includes six batteries 11 arranged in the X-axis direction with the positive terminal 11a located on the -Z direction side, three batteries 11 arranged in the Y-axis direction.

[0097] The tabs 11121 and 11131 intersect at five locations when viewed from above in the direction of the barrel axis J1 of each of the 12 batteries 11. The tab 11121 has connecting pieces 11121a, 11121b, 11121d, 11121e, 11121f and extension pieces 11121c, 11121h, 11121i. Here, the connecting piece 11121a connects the positive terminal 11a of the battery 11 arranged on the -Y direction side to the positive terminal 11a of the battery 11 arranged on the +X direction side and the +Y direction side relative to the battery 11. The connecting piece 11121b connects the positive terminal 11a of the battery 11 arranged on the +Y direction side to the positive terminal 11a of the battery 11 arranged on the +X direction side and the -Y direction side relative to the battery 11. The connection piece 11121d connects the positive terminal 11a of the battery 11 arranged on the -Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the +Y direction side relative to the battery 11. The connection piece 11121e connects the negative terminal 11b of the battery 11 arranged on the +Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the -Y direction side relative to the battery 11. The connection piece 11121f connects the negative terminal 11b of the battery 11 arranged on the -Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the +Y direction side relative to the battery 11. That is, the tab 11121 is configured to connect each of the six batteries 11 arranged along the X-axis direction on the -Y direction side to a battery 11 other than the battery 11 whose distance to each of the six batteries 11 located on the -Y direction side is the shortest among the six batteries 11 adjacent to the +Y direction.

[0098] The extension piece 11121c is continuous with the connection pieces 11121a, 11121b, 11121d, 11121e, and 11121f, and electrically connects the positive terminal 11a of the battery 11 disposed most on the -X direction side, the positive terminal 11a of the battery 11 disposed third in the +X direction from the battery 11 disposed most on the -X direction side, and the negative terminal 11b of the battery 11 disposed fifth in the +X direction from the battery 11 disposed most on the -X direction side. The extension piece 11121h extends from the connection portion of the connection pieces 11121a and 11121b in the +Y direction, and the front end portion is connected to the PCB 15. The extension piece 11121i extends from the connection portion of the connection pieces 11121d and 11121e in the +Y direction, and the front end portion is connected to the PCB 15.

[0099] The tab 11131 has connecting pieces 11131a, 11131b, 11131d, 11131e, 11131f and extending pieces 11131c, 11131h, 11131i. The connecting piece 11131a connects the positive terminal 11a of the battery 11 arranged on the +Y direction side to the positive terminal 11a of the battery 11 arranged on the +X direction side and the -Y direction side relative to the battery 11. The connecting piece 11131b connects the positive terminal 11a of the battery 11 arranged on the -Y direction side to the positive terminal 11a of the battery 11 arranged on the +X direction side and the +Y direction side relative to the battery 11. The connecting piece 11131d connects the positive terminal 11a of the battery 11 arranged on the +Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the -Y direction side relative to the battery 11. The connecting piece 11131e connects the negative terminal 11b of the battery 11 arranged on the -Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the +Y direction side relative to the battery 11. The connecting piece 11131f connects the negative terminal 11b of the battery 11 arranged on the +Y direction side to the negative terminal 11b of the battery 11 arranged on the +X direction side and the -Y direction side relative to the battery 11. That is, the tab 11131 is provided to connect each of the six batteries 11 arranged along the X-axis direction on the +Y direction side to the battery 11 other than the battery 11 whose distance to each of the six batteries 11 on the +Y direction side is the shortest among the six batteries 11 adjacent in the -Y direction.

[0100] The extension piece 11131c is continuous with the connection pieces 11131a, 11131b, 11131d, 11131e, and 11131f, and electrically connects the positive terminal 11a of the battery 11 arranged second in the +X direction from the battery 11 arranged closest to the -X direction, the negative terminal 11b of the battery 11 arranged fourth in the +X direction from the battery 11 arranged closest to the -X direction, and the negative terminal 11b of the battery 11 arranged closest to the +X direction. The extension piece 11131h extends from the connection portion of the connection pieces 11131b and 11131d in the +Y direction, and the front end portion is connected to the PCB 15. The extension piece 11131i extends from the connection portion of the connection pieces 11131e and 11131f in the +Y direction, and the front end portion is connected to the PCB 15.

[0101] It should be noted that, in this modification, the first battery group 111A and the second battery group 111B each include six batteries 11, but the number of batteries 11 constituting the first battery group and the second battery group is not limited to six. For example, the first battery group and the second battery group may each include eight or more batteries 11.

[0102] According to this structure, eight batteries 11 are connected to each other via the extension pieces 10121c, 10131c of the tabs 10121, 10131 or the extension pieces 10171c, 10181c of the tabs 10171, 10181. Alternatively, 12 batteries 11 are connected to each other via the extension pieces 11121c, 11131c of the tabs 11121, 11131. Thus, the resistance generated between the batteries 11 can be reduced.

[0103] In the embodiment, an example in which the battery 11 is a so-called cylindrical battery has been described, but the shape of the battery 11 is not limited thereto, and for example, a so-called prismatic battery may be used.

[0104] Although the embodiments and modifications of the present invention have been described above, the present invention is not limited thereto and includes forms obtained by appropriately combining the embodiments and modifications and forms obtained by appropriately changing these.

[0105] This application is based on Japanese Patent Application No. 2020-036218 filed on March 3, 2020 and Japanese Patent Application No. 2020-071780 filed on April 13, 2020. In this specification, the specification, claims, and drawings of Japanese Patent Application No. 2020-036218 as well as the specification, claims, and drawings of Japanese Patent Application No. 2020-071780 as a whole are incorporated by reference.

[0106] Industrial Applicability

[0107] The present invention is suitable as a battery pack including a plurality of batteries.

[0108] Description of Reference Numerals

[0109] 1, 2, 3, 4, 5, 6, 7, 8, 1001, 1002: battery pack, 11, 11A, 11B, 11C: battery, 11a: positive terminal, 11b: negative terminal, 15, 16: PCB, 101A, 111A: first battery group, 101B, 111B: second battery group, 121, 122, 131, 132, 171, 172, 181, 182, 2121, 2171, 3121, 3131, 3131 171, 3181, 4121, 4171, 5121, 5131, 5171, 5172, 5173, 5181, 5182, 5183, 6131, 6181, 10121, 10131, 10133, 10171, 10181, 11121, 11131: lugs, 151, 161: conductive patterns, 1211, 1212, 1213, 1221, 1222, 1223, 1311, 1312, 1313, 1321, 1322, 1323, 1711, 1712, 1713, 1721, 1722, 1723: sub-pole ears, 5131a, 5181a: repeated parts, 6121a, 6171a, 7121a, 7171a: joint parts, 10121a, 10121b, 10121d, 10131a, 10131b, 10131d, 11121a, 11121b, 1 1121d, 11121e, 11121f, 11131a, 11131b, 11131d, 11131e, 11131f: connecting plate, 10121c, 10131c, 10171c, 10181c, 10121h, 10131h, 11121c, 11121h, 11121i, 11131c, 11131h, 11131i: extension plate, J1: barrel axis, VL3: virtual plane.

Claims

1. A battery pack comprising: A battery pack, wherein a plurality of batteries having a cylindrical outer shape and having electrode terminals at the positive and negative ends in the cylindrical axis direction are arranged along a first direction orthogonal to the cylindrical axis direction with the cylindrical axes parallel to each other; and a tab that connects the electrode terminals at the ends of the positive sides of the plurality of batteries and is connected so that the plurality of batteries are arranged to be separated from each other, The plurality of batteries include the first battery, the second battery, and the third battery arranged in the order of a first battery, a second battery, and a third battery, The tab includes a first tab that is not connected to the second battery but is connected to the first battery and the third battery. Two batteries among the plurality of batteries that are adjacent to each other and at the shortest distance are not connected by the tabs, The ends of the tabs respectively connected to two batteries located at the outermost sides of one end in the first direction, adjacent to each other and at the shortest distance, which ends are not connected to the two batteries, are electrically connected via the printed circuit board.

2. The battery pack according to claim 1, wherein: The plurality of batteries include a fourth battery, the fourth battery being adjacent to a side of the third battery opposite to the second battery side and not connected to the first tab, The tabs include a second tab, The second electrode tab is not connected to the first battery and the third battery, but is connected to the second battery and the fourth battery.

3. The battery pack according to claim 2, wherein: When viewed from the positive side in the cylindrical axis direction, the first electrode tab intersects with the second electrode tab at at least one location.

4. The battery pack according to claim 2, wherein: When viewed in plan from a second direction perpendicular to the cylinder axis direction and the first direction, the first electrode tab intersects the second electrode tab at at least one location.

5. The battery pack according to claim 4, wherein: The plurality of batteries further include a fifth battery adjacent to the first battery in the second direction, a sixth battery adjacent to the second battery in the second direction, a seventh battery adjacent to the third battery in the second direction, and an eighth battery adjacent to the fourth battery in the second direction. The first electrode tab is not connected to the fifth battery and the seventh battery, but is connected to the sixth battery and the eighth battery. The second electrode tab is not connected to the sixth battery and the eighth battery, but is connected to the fifth battery and the seventh battery.

6. The battery pack according to claim 2, wherein: When viewed in plan from the cylinder axis direction, the first electrode tab and the second electrode tab do not overlap.

7. The battery pack according to claim 2, wherein: The first electrode tab and the second electrode tab are arranged so as to sandwich one of the plurality of batteries when viewed in plan from a second direction perpendicular to the cylinder axis direction and the first direction.

8. The battery pack according to any one of claims 2 to 7, wherein: A positive terminal is provided at the positive end of the first battery and the second battery in the cylinder axis direction. Negative terminals are provided at the ends of the third battery and the fourth battery on the positive side in the cylinder axis direction.

9. The battery pack according to any one of claims 1 to 7, wherein: The pole tab has a plurality of sub-pole tabs.

10. A battery pack comprising: A battery pack, wherein a plurality of batteries having a cylindrical outer shape and having electrode terminals at the positive and negative ends in the cylindrical axis direction are arranged along a first direction orthogonal to the cylindrical axis direction with the cylindrical axes parallel to each other; and a tab that connects the electrode terminals at the ends of the positive sides of the plurality of batteries and is connected so that the plurality of batteries are arranged to be separated from each other, The plurality of batteries include the first battery, the second battery, and the third battery arranged in the order of a first battery, a second battery, and a third battery, The tab includes a first tab that is not connected to the second battery but is connected to the first battery and the third battery. The plurality of batteries include a fourth battery, the fourth battery being adjacent to a side of the third battery opposite to the second battery side and not connected to the first tab, The tabs include a second tab, The second electrode tab is not connected to the first battery and the third battery, but is connected to the second battery and the fourth battery. When viewed in plan from the cylinder axis direction, the first electrode tab and the second electrode tab do not overlap.

11. A battery pack comprising: A battery pack, wherein a plurality of batteries having a cylindrical outer shape and having electrode terminals at the positive and negative ends in the cylindrical axis direction are arranged along a first direction orthogonal to the cylindrical axis direction with the cylindrical axes parallel to each other; and a tab that connects the electrode terminals at the ends of the positive sides of the plurality of batteries and is connected so that the plurality of batteries are arranged to be separated from each other, The plurality of batteries include the first battery, the second battery, and the third battery arranged in the order of a first battery, a second battery, and a third battery, The tab includes a first tab that is not connected to the second battery but is connected to the first battery and the third battery. The plurality of batteries include a fourth battery, the fourth battery being adjacent to a side of the third battery opposite to the second battery side and not connected to the first tab, The tabs include a second tab, The second electrode tab is not connected to the first battery and the third battery, but is connected to the second battery and the fourth battery. The first electrode tab and the second electrode tab are arranged so as to sandwich one of the plurality of batteries when viewed in plan from a second direction perpendicular to the cylinder axis direction and the first direction.

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