JP-7856534-B2 - battery cell

JP7856534B2JP 7856534 B2JP7856534 B2JP 7856534B2JP-7856534-B2

Inventors

村石康輔

Assignees

トヨタバッテリー株式会社

Dates

Publication Date: 20260511
Application Date: 20220916

Claims (7)

A battery cell comprising an electrode body, an electrolyte, and a case for housing the electrode body and the electrolyte, The case comprises a rectangular parallelepiped case body surrounded by a bottom wall, a periphery wall, and the periphery wall, and having a rectangular opening at the top facing the bottom wall, and a plate-shaped lid that is welded to the opening and seals the opening. The case body and the lid are joined at the joint portion of the periphery of the opening. When the longitudinal direction of the opening of the case body is defined as the length direction L, the width direction of the opening perpendicular to the length direction L is defined as the width direction W , and the height direction perpendicular to the length direction L and the width direction W is defined as the height direction Z , The joint portion between the case body and the lid is provided with a general portion along the length L of the rectangular opening and a stepped portion located inside the case in the height Z direction, relative to the general portion . Battery cell.
The stepped portion has a bottom portion parallel to the length L of the general portion and a connecting portion that connects the bottom portion and the general portion. The thickness of the bottom portion is smaller than the thickness of the general portion. The battery cell according to claim 1.
The thickness of the connecting portion gradually decreases from the general portion towards the bottom portion. The battery cell according to claim 2.
A step is provided in the portion of at least one of the case body and the lid that constitutes the stepped portion. The aforementioned step is provided along the stepped portion, The battery cell according to claim 1.
The outer surface of the portion of the peripheral wall adjacent to the stepped portion is provided with ribs extending in the longitudinal direction L of the joint portion. The rib has an outer surface portion which is the surface on the lid side, In the outer surface of the rib, the portion corresponding to the portion where the stepped portion is provided in the longitudinal direction L of the joint portion is provided, and the rib stepped portion is located closer to the bottom wall than the other portions of the outer surface of the rib. The distance between the stepped portion and the rib stepped portion is greater than the distance between the general portion and the other portion. The battery cell according to claim 1.
The peripheral wall is joined to the outer surface and comprises a flow channel component that constitutes a flow channel for cooling fluid, The rib is part of the flow channel component. The battery cell according to claim 5.
A battery cell comprising an electrode body, an electrolyte, and a case for housing the electrode body and the electrolyte, The case comprises a rectangular parallelepiped case body surrounded by a bottom wall, a periphery wall, and the periphery wall, and having a rectangular opening at the top facing the bottom wall, and a plate-shaped lid that is welded to the opening and seals the opening. The case body and the lid are joined at the joint portion of the periphery of the opening. The outer surface of the peripheral wall is provided with ribs parallel to the longitudinal direction L, which is the longitudinal direction of the opening of the case body . The rib has an outer surface portion which is the surface on the lid side, The outer surface of the rib is provided with a rib step portion that is located closer to the bottom wall than other parts of the outer surface of the rib. Battery cell.

Description

This invention relates to a battery cell. Patent Document 1 describes a battery comprising an outer casing, an electrode body, a non-aqueous electrolyte, and a sealing plate. The outer container has a bottom wall, a perimeter wall, and an opening surrounded by the perimeter wall and facing the bottom wall. Inside the outer container are the electrode body and the non-aqueous electrolyte. The sealing plate is welded to the outer casing to close the opening of the casing. A notch is provided on a portion of the periphery of the sealing plate. This notch opens onto the inner surface of the sealing plate. The portion of the sealing plate with the notch is a thinner section than the main body of the sealing plate. Therefore, if the pressure inside the battery increases due to overcharging or other factors, causing the outer casing and sealing plate to expand, the welded joint between the thin section and the outer casing will rupture, allowing the gas inside the battery to be released to the outside. Japanese Patent Publication No. 2003-17029 Figure 1 is a plan view of a battery stack comprising a battery cell according to the first embodiment.Figure 2 is an exploded perspective view of the battery cell body shown in Figure 1.Figure 3 is a side view of the lid shown in Figure 2, centered on the stepped portion of the lid.Figure 4 is a side view of the spacer shown in Figure 1.Figure 5 is a cross-sectional view of a battery cell along the line 5-5 in Figure 2.Figure 6 is a cross-sectional view of a battery cell along the line 6-6 in Figure 2.Figure 7 is a cross-sectional view of a battery cell along the line 7-7 in Figure 6.Figure 8 is a diagram corresponding to Figure 7, and is a cross-sectional view of the battery cell of the second embodiment.Figure 9 is a diagram corresponding to Figure 7, and is a cross-sectional view of the battery cell of the first modified example.Figure 10 is a diagram corresponding to Figure 7, and is a cross-sectional view of a battery cell of a second modified example.Figure 11 is a magnified plan view of a portion of the battery cell of the third modified example. <First Embodiment> The first embodiment of the battery cell will be described below with reference to Figures 1 to 7. As shown in Figure 1, the battery stack comprises a plurality of battery cells 10 arranged in a stacked configuration. The battery cell 10 comprises a battery cell body 10A and a spacer 40 provided adjacent to the battery cell body 10A in the stacking direction of the battery cell 10. The battery cell body 10A is, for example, a lithium-ion battery. <Battery cell body 10A> As shown in Figure 2, the battery cell body 10A comprises an electrode body 11, an electrolyte 12, and a case 13 that houses the electrode body 11 and the electrolyte 12. The electrode body 11 comprises a positive electrode, a negative electrode, and a separator (none of which are shown) provided between the positive electrode and the negative electrode. The electrolyte 12 is, for example, a composition containing a supporting salt in a non-aqueous solvent. Case 13 comprises a case body 20 and a lid 30. <Case body 20> As shown in Figure 2, the case body 20 is surrounded by a bottom wall 21, a peripheral wall 22, and an opening 22a facing the bottom wall 21. The bottom wall 21 is in the shape of a rectangular plate. In the following explanation, the long and short sides of the bottom wall 21 will be described as the length direction L and the width direction W, respectively. Furthermore, the direction perpendicular to both the length direction L and the width direction W will be described as the height direction Z. Case 13 of this embodiment has a symmetrical structure in the length direction L and a symmetrical structure in the width direction W. Therefore, in the following descriptions, one side of case 13 in the length direction L may be described, and the description of the other side may be omitted. Similarly, one side of case 13 in the width direction W may be described, and the description of the other side may be omitted. The peripheral wall 22 extends in the height direction Z from the periphery of the bottom wall 21 and has an opening 22a. The peripheral wall 22 has a pair of first wall portions 23 extending in the length direction L and a pair of second wall portions 24 extending in the width direction W. On the edge 25 of the first wall portion 23 opposite to the bottom wall 21, a pair of case step portions 26 are provided, which are located closer to the bottom wall 21 than the general portion 25a of the edge 25. The case step portion 26 is provided in the central part of the edge 25 in the longitudinal direction L. The case step portion 26 has a bottom portion 27 that extends along the longitudinal direction L, and a pair of connecting portions 28 that connect both ends of the bottom portion 27 in the longitudinal direction L to the general portion 25a. The connecting portions 28 are inclined such that they move closer to the