Battery housing and battery

Abstract

The present invention belongs to the technical field of batteries, and discloses a battery shell and a battery, wherein the battery shell comprises a cover plate body, a shell body and an insulating structural member, wherein a liquid injection hole is provided on a wall surface of the cover plate body or the shell body opposite to the pole ear of the pole group, and the insulating structural member comprises a first surface, a second surface, a buffer structure and a plurality of flow structures, wherein the buffer structure forms a buffer groove on the first surface and a buffer boss on the second surface, wherein the plurality of flow structures are arranged in the buffer groove, and a closed area is enclosed in the buffer groove, wherein the liquid injection hole is located in a projection of the closed area along a first direction, wherein the effective cross-sectional area of ​​the liquid injection hole is S1, and the total effective cross-sectional area of ​​the plurality of flow structures is S2, and S2 / S1<95% is satisfied. A single buffer is realized through the closed area, and a double buffer is realized by limiting the ratio of the total effective cross-sectional area S2 to the effective cross-sectional area S1, thereby avoiding damage to the pole group during liquid injection and improving product quality.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a battery housing and a battery. Background Art

[0002] Lithium-ion batteries are currently widely used in various fields such as transportation power sources, power energy storage sources, new energy storage power sources, aerospace and military industries due to their advantages of large capacity, high working voltage, strong charge retention ability, long cycle life, etc. The structure of a single lithium battery generally includes a pole group, electrolyte, cover plate, housing, internal and external insulation structures, etc. Among them, the cover plate and the housing are usually fixed by laser welding to form a sealed space with a certain structural strength to protect the pole group. The cover plate generally integrates functional areas such as pole columns, explosion-proof valves, and liquid injection holes. The liquid injection hole is usually arranged on the cover plate, and a through hole communicating with the liquid injection hole is opened on the internal insulation structure, so as to facilitate the electrolyte to flow in and achieve the purpose of wetting the pole group.

[0003] In order to accelerate the flow rate of the electrolyte into the interior, on the one hand, the liquid injection hole on the cover plate is concentrically arranged with the flow hole on the internal insulation structure, so that the electrolyte flowing out of the liquid injection hole can directly enter the through hole directly below. On the other hand, the effective cross-sectional area of the flow hole is larger than that of the liquid injection hole, so that when the electrolyte enters the flow hole from the liquid injection hole, there will be no obstruction.

[0004] However, when the electrolyte is injected, in addition to the gravity of its own fall, there is also the injection pressure provided by the external liquid injection device. And the structural strength of the pole pieces of the pole group is relatively low. When the electrolyte is injected from the through hole, its own gravity and the carried injection pressure will cause a large impact force on the pole group, so that the pole pieces of the pole group are easily damaged due to the impact of the electrolyte, such as poor phenomena such as powder falling, seriously affecting the product quality and reducing the production yield. Summary of the Invention

[0005] The purpose of the present invention is to provide a battery housing and a battery, which reduce the impact force during electrolyte injection, reduce the damage to the pole group during liquid injection, improve the product quality, and increase the product yield.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] On the one hand, a battery housing is provided. The battery housing includes a cover plate body, a housing body, and an insulation structure member. The housing body is a hollow housing structure with an open mouth. The cover plate body is arranged at the open mouth of the housing body to form a receiving cavity for receiving the pole group. A liquid injection hole is opened on the wall surface of the cover plate body or the housing body opposite to the pole ear of the pole group. The insulation structure member is located in the receiving cavity and is arranged on the side where the pole group extends out of the pole ear.

[0008] The insulating structural member includes a first surface, a second surface, a buffer structure and a plurality of flow structures, wherein the buffer structure is recessed from the first surface to the second surface and protrudes from the second surface to form a buffer groove on the first surface and a buffer boss on the second surface, wherein the plurality of flow structures all penetrate the insulating structural member and are arranged in the buffer groove, wherein the plurality of flow structures are used to enclose a closed area in the buffer groove opposite to the injection hole, and along the first direction, the injection hole is located within a projection of the closed area on the wall surface of the cover plate body or the shell body;

[0009] The effective cross-sectional area of ​​the injection hole is S1, the total effective cross-sectional area of ​​the plurality of flow structures is S2, and S2 / S1<95%.

[0010] Optionally, a projection area of ​​the closed area along the first direction on a wall surface of the cover body or the shell body is S3, and satisfies 1.3≤S3 / S1≤1.6.

[0011] Optionally, a projection area of ​​the buffer groove along the first direction on the wall surface of the cover body or the shell body is S4, and satisfies 35%≤S2 / S4≤50%.

[0012] Optionally, a liquid injection boss is provided on a surface of the cover body or the wall of the shell body facing the insulating structure, the liquid injection hole is opened on the liquid injection boss, and the liquid injection boss is inserted into the buffer groove.

[0013] Optionally, the height dimension of the injection boss is H1, and satisfies 0.8mm≤H1≤1.1mm.

[0014] Optionally, the depth dimension of the buffer groove is H2, and satisfies 0.3mm≤H2-H1≤0.5mm. Optionally, the injection boss and the buffer groove are interference fit.

[0015] Optionally, the height dimension of the buffer boss protruding from the second surface is H3, and satisfies 0.5mm≤H3≤1mm.

[0016] Optionally, a weight-reducing groove is further provided on a side of the insulating structure away from the cover plate body, and a plurality of cross-distributed reinforcing ribs are provided in the weight-reducing groove.

[0017] On the other hand, a battery is provided, comprising a pole group and a battery casing as described in any one of the above items, wherein the pole group is accommodated in the battery casing.

[0018] Beneficial effects of the present invention:

[0019] The present invention provides a battery housing. In the buffer groove of the insulating structural member, a closed area opposite to the liquid injection hole is enclosed by a plurality of flow-through structures penetrating the insulating structural member, and the liquid injection hole is located within the projection of the closed area along the first direction. When the electrolyte flows out of the liquid injection hole, it will first fall on the closed area and then flow into the flow-through structures around the closed area before flowing out of the insulating structural member. Thus, the closed area is used to relieve the impact force when injecting the electrolyte, achieving a first-level buffer. Moreover, the ratio of the total effective cross-sectional area S2 of the plurality of flow-through structures to the effective cross-sectional area S1 of the liquid injection hole is limited, such that the ratio satisfies S2 / S1 < 95%. On the premise of meeting the flow rate requirements, when the electrolyte flows out of the insulating structural member through the plurality of flow-through structures, a part of the electrolyte cannot flow out in time, thereby generating turbulence to offset a part of the impact of the electrolyte itself, thus achieving a second-level buffer. By using the double buffer, the impact force when the electrolyte flows out of the insulating structural member is greatly weakened, thereby avoiding damage to the electrode group during liquid injection, improving the product quality, and increasing the product yield.

[0020] The present invention also provides a battery. By applying the above battery housing, the protection of the electrode group during liquid injection is effectively improved, thereby avoiding damage to the electrode group, reducing the scrap rate of the product, and reducing the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a structural exploded view of the cover plate body and the insulating structural member in the battery housing provided by the present invention;

[0022] Figure 2 is a partial structural schematic diagram of the insulating structural member in the battery housing provided by the present invention from a first perspective;

[0023] Figure 3 is a partial structural schematic diagram of the insulating structural member in the battery housing provided by the present invention from a second perspective;

[0024] Figure 4 is a partial structural schematic diagram of the battery provided by the present invention.

[0025] In the figure:

[0026] 100. Electrode group;

[0027] 1. Cover plate body; 11. Liquid injection hole; 12. Liquid injection boss;

[0028] 2. Insulating structural member; 21. First surface; 22. Second surface; 23. Buffer structure; 231. Buffer groove; 232. Buffer boss; 233. Closed area; 24. Flow-through structure; 25. Weight reduction groove; 26. Reinforcing rib plate;

[0029] 3. Housing body. Detailed Implementation Manner

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of convenience of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0031] In the description of the present invention, unless otherwise clearly specified and defined, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0032] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature can include the direct contact between the first and second features, or can also include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.

[0033] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and do not have special meanings.

[0034] Since the liquid injection holes on the cover plate and the through holes on the inner insulation structure are concentrically arranged, and the effective cross-sectional area of the through holes is larger than that of the liquid injection holes, when the electrolyte is injected, due to the gravity of its own downward fall and the injection pressure provided by the external liquid injection device, the electrolyte will cause a relatively large impact on the electrode group when injected, resulting in the electrode plates of the electrode group being easily damaged due to the impact of the electrolyte, such as adverse phenomena like powder falling off, seriously affecting the product quality and reducing the production yield.

[0035] Therefore, in order to reduce the impact force during electrolyte injection, reduce the damage to the electrode group during injection, improve the product quality, and increase the product yield, this embodiment provides a battery housing.

[0036] As Figures 1 to 4 shown, the battery housing includes a cover plate body 1, a housing body 3, and an insulating structure member 2. The housing body 3 is a hollow shell structure with an open mouth. The cover plate body 1 is arranged at the open mouth of the housing body 3 to form a receiving cavity for receiving the electrode group 100. A liquid injection hole 11 is opened on the wall surface of the cover plate body 1 or the housing body 3 opposite to the electrode tab of the electrode group 100. The insulating structure member 2 is located in the receiving cavity and is arranged on one side where the electrode group 100 extends out the electrode tab. The insulating structure member 2 includes a first surface 21, a second surface 22, a buffer structure 23, and a plurality of flow-through structures 24. The buffer structure 23 is recessed from the first surface 21 towards the second surface 22 and protrudes from the second surface 22, so as to form a buffer groove 231 on the first surface 21 and a buffer boss 232 on the second surface 22. The plurality of flow-through structures 24 all penetrate through the insulating structure member 2 and are arranged in the buffer groove 231. The plurality of flow-through structures 24 are used to enclose a closed area 233 opposite to the liquid injection hole 11 in the buffer groove 231. Along the first direction, the liquid injection hole 11 is located within the projection of the closed area 233 on the wall surface of the cover plate body 1 or the housing body 3. The effective cross-sectional area of the liquid injection hole 11 is S1, and the total effective cross-sectional area of the plurality of flow-through structures 24 is S2, and S2 / S1 < 95% is satisfied.

[0037] This battery housing uses the plurality of flow-through structures 24 that penetrate through the insulating structure member 2 to enclose a closed area 233 opposite to the liquid injection hole 11 in the buffer groove 231 of the insulating structure member 2, and makes the liquid injection hole 11 located within the projection of the closed area 233 along the first direction, so that when the electrolyte flows out from the liquid injection hole 11, it will first fall on the closed area 233, and then flow into the flow-through structures 24 around the closed area 233 and then flow out of the insulating structure member 2. Thus, the closed area 233 is used to relieve the impact force when injecting the electrolyte, realizing a first-stage buffer. And the ratio of the total effective cross-sectional area S2 of the plurality of flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is limited, so that the ratio of the two satisfies S2 / S1 < 95%. On the premise of meeting the flow rate requirements, when the electrolyte flows out of the insulating structure member 2 through the plurality of flow-through structures 24, part of the electrolyte cannot flow out in time, thus generating turbulence to offset part of the impact of the electrolyte itself, thereby realizing a second-stage buffer. By using the double buffer, the impact force when the electrolyte flows out of the insulating structure member 2 is greatly weakened, thus avoiding the damage to the electrode group 100 during injection, improving the product quality, and increasing the product yield.

[0038] In this embodiment, the liquid injection hole 11 is a circular through hole with a hole diameter of d1. Therefore, the effective cross-sectional area S1 of the liquid injection hole 11 = (d1 / 2)2 ·π, and the flow structure 24 for enclosing the closed area 233 in the buffer groove 231 is a plurality of circular through-holes, the number of which can be freely set according to requirements. In this embodiment, n circular through-holes are provided, and the aperture of each circular through-hole is set as d2. At this time, the total effective cross-sectional area of the plurality of flow structures 24 is S2 = (d2 / 2) 2 ·π·n.

[0039] The buffer groove 231 formed on the first surface 21 and the buffer boss 232 formed on the second surface 22 are both formed simultaneously when the buffer structure 23 is recessed. Therefore, the shapes of the buffer groove 231 and the buffer boss 232 are the same, and their shapes can be freely set according to requirements. For example, the buffer groove 231 and the buffer boss 232 with circular cross-sections are adopted, or the buffer groove 231 and the buffer boss 232 with rectangular cross-sections are adopted. Moreover, the number and shape of the flow structures 24 provided in the buffer groove 231 can also be freely set according to actual requirements. In this embodiment, the buffer structure 23 forms a circular buffer groove 231 and a circular buffer boss 232. In addition, the liquid injection hole 11 can be opened at different positions according to the structural design. When the side of the electrode group 100 extending out of the tab is opposite to the cover body 1, the liquid injection hole 11 is opened on the cover body 1. When the side of the electrode group 100 extending out of the tab is opposite to a wall surface of the housing body 3, at this time, the liquid injection hole 11 is opened on the wall surface of the housing body 3 opposite to the tab. In this embodiment, the liquid injection hole 11 is opened on the cover body 1. And this battery housing can be applied to different battery types, such as blade batteries, square shell batteries, large cylindrical batteries, etc. In this embodiment, this battery housing is applied to blade batteries.

[0040] Optionally, as Figures 2 to 3 shown, the projected area of the closed area 233 on the wall surface of the cover body 1 or the housing body 3 along the first direction is S3, and it satisfies 1.3 ≤ S3 / S1 ≤ 1.6. By setting the projected area of the closed area 233 on the wall surface of the cover body 1 or the housing body 3 along the first direction as S3, and limiting the ratio of the projected area S3 of the closed area 233 on the wall surface of the cover body 1 or the housing body 3 along the first direction to the effective cross-sectional area S1 of the liquid injection hole 11, so that the ratio of the two satisfies 1.3 ≤ S3 / S1 ≤ 1.6, on the one hand, it avoids that the area of the closed area 233 is too small, weakening the buffering effect of the closed area 233 on the electrolyte, and on the other hand, it avoids that the area of the closed area 233 is too large, resulting in a reduction in the total effective cross-sectional area S2 of the flow structure 24 and affecting the flow rate of the electrolyte.

[0041] Optionally, as Figures 2 to 3As shown, the projected area of the buffer groove 231 on the wall surface of the cover plate body 1 or the housing body 3 in the first direction is S4, and it satisfies 35% ≤ S2 / S4 ≤ 50%. By setting the projected area of the buffer groove 231 on the wall surface of the cover plate body 1 or the housing body 3 in the first direction as S4, and limiting the ratio between the total effective cross-sectional area S2 of the flow-through structure 24 and the projected area S4 of the buffer groove 231 on the wall surface of the cover plate body 1 or the housing body 3 in the first direction, so that the ratio of the two satisfies 35% ≤ S2 / S4 ≤ 50%, on the one hand, it avoids that the proportion of the total effective cross-sectional area S2 of the flow-through structure 24 is too small, resulting in too low a flow rate of the electrolyte flowing out of the insulating structure member 2 through the flow-through structure 24, and on the other hand, it avoids that the proportion of the total effective cross-sectional area S2 of the flow-through structure 24 is too large, thus shortening the path of the electrolyte flowing into the flow-through structure 24, and reducing the buffering effect of the closed area 233.

[0042] In this embodiment, in order to verify the influence of the effective cross-sectional area S1 of the liquid injection hole 11, the total effective cross-sectional area S2 of the plurality of flow-through structures 24, the projected area S3 of the closed area 233 on the wall surface of the cover plate body 1 or the housing body 3 in the first direction, and the projected area S4 of the buffer groove 231 on the wall surface of the cover plate body 1 or the housing body 3 in the first direction on the injection rate of the electrolyte and the protection performance of the electrode group 100, as shown in Table 1, ten experimental groups are provided to verify the relationship among the four. Among them, for the influence on the protection performance of the electrode group 100, after the liquid injection is completed, X-ray detection is used to determine whether the electrode group 100 is damaged, and the liquid injection time is recorded. If the time to complete the liquid injection is less than 25 min, it meets the requirements of the liquid injection process. Since in this embodiment, the liquid injection hole 11 is opened on the cover plate body 1, the projected area S3 is the projection of the closed area 233 on the cover plate body 1 in the first direction, and the projected area S4 is the projection of the buffer groove 231 on the cover plate body 1 in the first direction.

[0043] Table 1

[0044]

[0045] In experimental group 1, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 , the total effective cross-sectional area S2 of the plurality of flow-through structures 24 is set to 25.5 mm 2 , the projected area S3 of the closed area 233 on the cover plate body 1 in the first direction is set to 45 mm 2 , and the projected area S4 of the buffer groove 231 on the cover plate body 1 in the first direction is set to 63.75 mm 2, at this time, the ratio S2 / S1 of the total effective cross-sectional area S2 of the multiple flow structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 85%, the ratio S3 / S1 of the projected area S3 of the closed area 233 on the cover body 1 in the first direction to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.5, and the ratio S2 / S4 of the total effective cross-sectional area S2 of the flow structure 24 to the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is 40%. After experimental verification, the liquid injection time is 23 min, and no damage is found in the electrode group 100.

[0046] In experimental group 2, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 , the total effective cross-sectional area S2 of the multiple flow structures 24 is set to 25.5 mm 2 , the projected area S3 of the closed area 233 on the cover body 1 in the first direction is set to 45 mm 2 , the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is set to 85 mm 2 , at this time, the ratio S2 / S1 of the total effective cross-sectional area S2 of the multiple flow structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 85%, the ratio S3 / S1 of the projected area S3 of the closed area 233 on the cover body 1 in the first direction to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.5, and the ratio S2 / S4 of the total effective cross-sectional area S2 of the flow structure 24 to the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is 30%. After experimental verification, the liquid injection time is 23.4 min, and no damage is found in the electrode group 100.

[0047] In experimental group 3, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 , the total effective cross-sectional area S2 of the multiple flow structures 24 is set to 25.5 mm 2 , the projected area S3 of the closed area 233 on the cover body 1 in the first direction is set to 45 mm 2 , the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is set to 42.5 mm 2 , at this time, the ratio S2 / S1 of the total effective cross-sectional area S2 of the multiple flow structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 85%, the ratio S3 / S1 of the projected area S3 of the closed area 233 on the cover body 1 in the first direction to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.5, and the ratio S2 / S4 of the total effective cross-sectional area S2 of the flow structure 24 to the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is 60%. After experimental verification, the liquid injection time is 22.6 min, and no damage is found in the electrode group 100.

[0048] In experimental group 4, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 and the total effective cross-sectional area S2 of multiple flow-through structures 24 is set to 25.5 mm 2 The projected area S3 of the closed area 233 on the cover body 1 in the first direction is set to 36 mm 2 The projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is set to 63.75 mm 2 At this time, the ratio S2 / S1 of the total effective cross-sectional area S2 of multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 85%, and the ratio S3 / S1 of the projected area S3 of the closed area 233 on the cover body 1 in the first direction to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.2. The ratio S2 / S4 between the total effective cross-sectional area S2 of the flow-through structure 24 and the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is 40%. After experimental verification, the liquid injection time is 22.3 min, and no damage is found in the electrode group 100.

[0049] In experimental group 5, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 and the total effective cross-sectional area S2 of multiple flow-through structures 24 is set to 25.5 mm 2 The projected area S3 of the closed area 233 on the cover body 1 in the first direction is set to 54 mm 2 The projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is set to 63.75 mm 2 At this time, the ratio S2 / S1 of the total effective cross-sectional area S2 of multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 85%, and the ratio S3 / S1 of the projected area S3 of the closed area 233 on the cover body 1 in the first direction to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.8. The ratio S2 / S4 between the total effective cross-sectional area S2 of the flow-through structure 24 and the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is 40%. After experimental verification, the liquid injection time is 23.6 min, and no damage is found in the electrode group 100.

[0050] In experimental group 6, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 and the total effective cross-sectional area S2 of multiple flow-through structures 24 is set to 29.4 mm 2 The projected area S3 of the closed area 233 on the cover body 1 in the first direction is set to 45 mm 2 The projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is set to 75.5 mm 2, at this time, the ratio S2 / S1 of the total effective cross-sectional area S2 of the multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 98%, the ratio S3 / S1 of the projected area S3 of the closed area 233 along the first direction on the cover body 1 to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.5, the ratio S2 / S4 of the total effective cross-sectional area S2 of the flow-through structure 24 to the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is 40%. After experimental verification, the liquid injection time is 21 min, and the electrode group 100 is damaged, with a proportion of about 0.013%.

[0051] In experimental group 7, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 , the total effective cross-sectional area S2 of the multiple flow-through structures 24 is set to 29.4 mm 2 , the projected area S3 of the closed area 233 along the first direction on the cover body 1 is set to 45 mm 2 , the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is set to 98 mm 2 , at this time, the ratio S2 / S1 of the total effective cross-sectional area S2 of the multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 98%, the ratio S3 / S1 of the projected area S3 of the closed area 233 along the first direction on the cover body 1 to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.5, the ratio S2 / S4 of the total effective cross-sectional area S2 of the flow-through structure 24 to the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is 30%. After experimental verification, the liquid injection time is 21.3 min, and the electrode group 100 is damaged, with a proportion of about 0.010%.

[0052] In experimental group 8, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 , the total effective cross-sectional area S2 of the multiple flow-through structures 24 is set to 29.4 mm 2 , the projected area S3 of the closed area 233 along the first direction on the cover body 1 is set to 45 mm 2 , the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is set to 49 mm 2 , at this time, the ratio S2 / S1 of the total effective cross-sectional area S2 of the multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 98%, the ratio S3 / S1 of the projected area S3 of the closed area 233 along the first direction on the cover body 1 to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.5, the ratio S2 / S4 of the total effective cross-sectional area S2 of the flow-through structure 24 to the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is 60%. After experimental verification, the liquid injection time is 20.7 min, and the electrode group 100 is damaged, with a proportion of about 0.015%.

[0053] In experimental group 9, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 , the total effective cross-sectional area S2 of multiple flow-through structures 24 is set to 29.4 mm 2 , the projected area S3 of the closed area 233 along the first direction on the cover body 1 is set to 36 mm 2 , the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is set to 73.5 mm 2 , at this time, the ratio S2 / S1 of the total effective cross-sectional area of multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 98%, the ratio S3 / S1 of the projected area S3 of the closed area 233 along the first direction on the cover body 1 to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.2, and the ratio S2 / S4 between the total effective cross-sectional area S2 of the flow-through structures 24 and the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is 40%. After experimental verification, the liquid injection time is 20.4 min, and the electrode group 100 is damaged, with a proportion of about 0.015%.

[0054] In experimental group 10, the effective cross-sectional area S1 of the liquid injection hole 11 is set to 30 mm 2 , the total effective cross-sectional area S2 of multiple flow-through structures 24 is set to 29.4 mm 2 , the projected area S3 of the closed area 233 along the first direction on the cover body 1 is set to 54 mm 2 , the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is set to 73.5 mm 2 , at this time, the ratio S2 / S1 of the total effective cross-sectional area of multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is 98%, the ratio S3 / S1 of the projected area S3 of the closed area 233 along the first direction on the cover body 1 to the effective cross-sectional area S1 of the liquid injection hole 11 is 1.8, and the ratio S2 / S4 between the total effective cross-sectional area S2 of the flow-through structures 24 and the projected area S4 of the buffer groove 231 along the first direction on the cover body 1 is 40%. After experimental verification, the liquid injection time is 21.5 min, and the electrode group 100 is damaged, with a proportion of about 0.010%.

[0055] The following conclusions can be drawn from the above ten experimental examples:

[0056] It can be seen from the comparison between Experimental Group 1 and Experimental Group 6 that when the ratio of the projected area S3 of the closed area 233 on the cover body 1 in the first direction to the effective cross-sectional area S1 of the liquid injection hole 11 satisfies the range of 1.3 ≤ S3 / S1 ≤ 2, and the ratio between the total effective cross-sectional area S2 of the flow-through structure 24 and the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction satisfies the range of 35% ≤ S2 / S4 ≤ 50%, if the ratio of the total effective cross-sectional area S2 of multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 satisfies the range of S2 / S1 < 95%, at this time, no damage is found in the electrode group 100, the buffering effect is good, and the liquid injection time is 23 min, which is less than the set time of 25 min. Therefore, it meets the liquid injection process requirements. However, if the ratio of the total effective cross-sectional area S2 of multiple flow-through structures 24 to the effective cross-sectional area S1 of the liquid injection hole 11 is greater than the maximum value of the range of S2 / S1 < 95%, although the liquid injection time is 21 min, which is much less than the set time of 25 min, due to the excessive total effective cross-sectional area S2 of multiple flow-through structures 24, the buffering ability is poor, resulting in damage to the electrode group 100 with a proportion of about 0.013%.

[0057] It can be seen from the comparison between Experimental Group 1 and Experimental Group 2 and the comparison between Experimental Group 6 and Experimental Group 7 that if the ratio between the total effective cross-sectional area S2 of the flow-through structure 24 and the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is less than the minimum value of the range of 35% ≤ S2 / S4 ≤ 50%, although the liquid injection time is extended, the buffering ability of the electrolyte is improved.

[0058] It can be seen from the comparison between Experimental Group 1 and Experimental Group 3 and the comparison between Experimental Group 6 and Experimental Group 8 that if the ratio between the total effective cross-sectional area S2 of the flow-through structure 24 and the projected area S4 of the buffer groove 231 on the cover body 1 in the first direction is greater than the maximum value of the range of 35% ≤ S2 / S4 ≤ 50%, although the liquid injection time is shortened, the buffering ability of the electrolyte is reduced.

[0059] It can be seen from the comparison between Experimental Group 1 and Experimental Group 4 and the comparison between Experimental Group 6 and Experimental Group 9 that if the ratio of the projected area S3 of the closed area 233 on the cover body 1 in the first direction to the effective cross-sectional area S1 of the liquid injection hole 11 is less than the minimum value of the range of 1.3 ≤ S3 / S1 ≤ 2, although the liquid injection time is shortened, the buffering ability of the electrolyte is reduced.

[0060] It can be seen from the comparison between Experimental Group 1 and Experimental Group 5 and the comparison between Experimental Group 6 and Experimental Group 10 that if the ratio of the projected area S3 of the closed area 233 on the cover body 1 in the first direction to the effective cross-sectional area S1 of the liquid injection hole 11 is greater than the maximum value of the range of 1.3 ≤ S3 / S1 ≤ 2, although the liquid injection time is extended, the buffering ability of the electrolyte is improved.

[0061] Optionally, as Figures 2 to 3 shown, a liquid injection boss 12 is provided on the surface of the cover body 1 or the wall surface of the housing body 3 facing the insulating structural member 2. The liquid injection hole 11 is opened on the liquid injection boss 12, and the liquid injection boss 12 is inserted into the buffer groove 231. By providing the liquid injection boss 12 inserted into the buffer groove 231 on the wall surface of the cover body 1 or the housing body 3, the flow path of the electrolyte is guided, so that the electrolyte directly enters the buffer groove 231 after flowing out of the liquid injection hole 11, avoiding the electrolyte from scattering after flowing out of the liquid injection hole 11 and entering the gap between the wall surface of the cover body 1 or the housing body 3 and the insulating structural member 2. In this embodiment, the shape of the liquid injection boss 12 matches that of the buffer groove 231 to ensure the sealing performance after the two are inserted.

[0062] Furthermore, as Figures 1 to 3 shown, the height dimension of the liquid injection boss 12 is H1, and 0.8 mm ≤ H1 ≤ 1.1 mm is satisfied. By setting the height dimension of the liquid injection boss 12 as H1 and limiting the height dimension H1 of the liquid injection boss 12 to satisfy 0.8 mm ≤ H1 ≤ 1.1 mm, on the one hand, it is avoided that the protruding height of the liquid injection boss 12 is too small, resulting in too small a depth inserted into the buffer groove 231, and there is a risk that the electrolyte enters the gap between the wall surface of the cover body 1 or the housing body 3 and the insulating structural member 2. On the other hand, it is avoided that the protruding height of the liquid injection boss 12 is too large, and the gap between the liquid injection boss 12 and the bottom of the buffer groove 231 is too small, affecting the outflow of the electrolyte.

[0063] In this embodiment, the height dimension H1 of the liquid injection boss 12 can be any value between 0.8 mm and 1.1 mm or the range between any two values, such as 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, 1.05 mm, 1.1 mm, etc.

[0064] Optionally, as Figures 1 to 3 shown, the depth dimension of the buffer groove 231 is H2, and 0.3 mm ≤ H2 - H1 ≤ 0.5 mm is satisfied. By setting the depth dimension of the buffer groove 231 as H2 and limiting the difference between the depth dimension H2 of the buffer groove 231 and the height dimension H1 of the liquid injection boss 12 protruding from the surface of the cover body 1 facing the insulating structural member 2, so that the difference between the two satisfies 0.3 mm ≤ H2 - H1 ≤ 0.5 mm, on the one hand, enough clearance is reserved between the liquid injection boss 12 and the bottom of the buffer groove 231 to avoid interference between the two. On the other hand, it is avoided that the clearance is too small, affecting the outflow speed of the electrolyte.

[0065] In this embodiment, the difference between the depth dimension H2 of the buffer groove 231 and the height dimension H1 of the injection boss 12 protruding from the surface of the cover body 1 toward the insulating structure 2 can be any value between 0.3mm and 0.5mm or a range between any two values, for example 0.3mm, 0.35mm, 0.4mm, 0.45mm, 1mm, 0.5mm, etc.

[0066] Optionally, the injection boss 12 and the buffer groove 231 are interference fit. By setting the injection boss 12 and the buffer groove 231 to be interference fit, the injection boss 12 and the buffer groove 231 are tightly fitted after being plugged in, the assembly gap between the two is eliminated, the sealing after assembly is ensured, and the electrolyte is prevented from overflowing from the gap between the injection boss 12 and the buffer groove 231.

[0067] Alternatively, if Figures 1 to 3 As shown, the height dimension of the buffer boss 232 protruding from the second surface 22 is H3, and satisfies 0.5mm≤H3≤1mm. By setting the height dimension of the buffer boss 232 protruding from the second surface 22 to H3, and limiting the height dimension H3 of the buffer boss 232 protruding from the second surface 22 to satisfy 0.5mm≤H3≤1mm, it is avoided that the height of the buffer boss 232 is too large, which occupies more space, limits the volume of the pole group 100, and reduces the energy density.

[0068] In this embodiment, the height dimension H3 of the buffer boss 232 protruding from the second surface 22 can be any value between 0.5 mm and 1 mm or a range between any two values, for example, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, etc.

[0069] Alternatively, if Figure 1 As shown, a weight-reducing groove 25 is further provided on the side of the insulating structure 2 facing away from the cover body 1, and a plurality of cross-distributed reinforcing ribs 26 are provided in the weight-reducing groove 25. By providing a weight-reducing groove 25 on the side of the insulating structure 2 facing away from the cover body 1, and providing a plurality of cross-distributed reinforcing ribs 26 in the weight-reducing groove 25, the insulating structure 2 is lightweighted while ensuring that it still has sufficient structural strength.

[0070] In this embodiment, the insulating structural member 2 is a plastic member integrally formed by an injection molding process, on the one hand to ensure the insulation of the insulating structural member 2, and on the other hand to facilitate the formation of the required flow guide structure buffer structure 23, circulation structure 24, weight reduction groove 25 and reinforcing ribs 26 on the insulating structural member 2 during production.

[0071] In this embodiment, a battery is further provided. The battery includes a pole group 100 and the above-mentioned battery housing, and the pole group 100 is accommodated in the battery housing. By applying the above-mentioned battery housing, the protection of the pole group 100 during liquid injection is effectively improved, thereby avoiding damage to the pole group 100, reducing the scrap rate of products, and reducing the manufacturing cost.

[0072] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. Battery housing, characterized in that, The battery housing includes a cover body, a housing body, and an insulating structure. The housing body is a hollow shell structure with an opening. The cover body is disposed at the opening of the housing body to form a receiving cavity for accommodating the electrode group. A liquid injection hole is formed on the wall surface of the cover body or the housing body opposite to the electrode tab of the electrode group. The insulating structure is located in the receiving cavity and is disposed on one side of the electrode group where the electrode tab extends; The insulating structure includes a first surface, a second surface, a buffer structure, and a plurality of flow-through structures. The buffer structure is recessed from the first surface towards the second surface and protrudes from the second surface, so as to form a buffer groove on the first surface and a buffer boss on the second surface. A plurality of the flow-through structures all penetrate the insulating structure and are disposed in the buffer groove. The plurality of flow-through structures are used to enclose a closed area opposite to the liquid injection hole in the buffer groove. Along a first direction, the liquid injection hole is located within the projection of the closed area on the wall surface of the cover body or the housing body; The effective cross-sectional area of the liquid injection hole is S1, and the total effective cross-sectional area of the plurality of flow-through structures is S2, and S2 / S1 < 95% is satisfied.

2. The battery housing according to claim 1, wherein The projected area of the closed area on the wall surface of the cover body or the housing body along the first direction is S3, and 1.3 ≤ S3 / S1 ≤ 1.6 is satisfied.

3. The battery housing according to claim 1, characterized in that, The projected area of the buffer groove on the wall surface of the cover body or the housing body along the first direction is S4, and 35% ≤ S2 / S4 ≤ 50% is satisfied.

4. The battery housing according to claim 1, characterized in that, A liquid injection boss is provided on the surface of the wall of the cover body or the housing body facing the insulating structure. The liquid injection hole is formed on the liquid injection boss, and the liquid injection boss is inserted into the buffer groove.

5. The battery housing according to claim 4, characterized in that, The height dimension of the liquid injection boss is H1, and 0.8 mm ≤ H1 ≤ 1.1 mm is satisfied.

6. The battery housing according to claim 5, characterized in that, The depth dimension of the buffer groove is H2, and 0.3 mm ≤ H2 - H1 ≤ 0.5 mm is satisfied.

7. The battery housing according to claim 4, characterized in that, The liquid injection boss and the buffer groove are in interference fit.

8. The battery housing according to claim 1, wherein, The height dimension of the buffer boss protruding from the second surface is H3, and 0.5 mm ≤ H3 ≤ 1 mm is satisfied.

9. The battery housing according to claim 1, characterized in that, A weight reduction groove is further provided on the side of the insulating structure facing away from the cover body, and a plurality of cross-distributed reinforcing rib plates are provided in the weight reduction groove.

10. A battery, characterized in that, The battery includes an electrode group and the battery housing according to any one of claims 1-9, and the electrode group is accommodated in the battery housing.

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