Battery monomer and battery pack

Abstract

The utility model relates to the technical field of new energy batteries, and discloses a single battery and a battery pack, the single battery comprises: a housing having an accommodating cavity; the electrode assembly is arranged in the accommodating cavity; the cover plate comprises a top cover piece and lower plastic, and the top cover piece is provided with a liquid injection hole; the lower plastic comprises a body and an abutting table, the abutting table comprises a side plate and a bottom plate connected with the side plate, the body is fixedly connected with the side plate, the bottom plate abuts against the electrode assembly in the first direction, a slow flow cavity is defined by the side plate, the bottom plate and the top cover piece, the slow flow cavity is communicated with the liquid injection hole, the liquid injection hole and the bottom plate are oppositely arranged in the first direction, and the side plate is further provided with an opening. The opening communicates with the slow flow cavity and the containing cavity. When the electrolyte is injected, the electrolyte impacts the bottom plate in the first direction, slows down in the slow flow cavity and then enters the containing cavity through the opening, and the electrolyte is prevented from directly impacting the electrode assembly; the bottom plate abuts against the electrode assembly in the first direction, enough electrolyte buffer space can be guaranteed, and the phenomenon of liquid overflow is avoided.

Description

Technical Field

[0001] This utility model relates to the field of new energy battery technology, and in particular to a battery cell and battery pack. Background Technology

[0002] Lithium-ion batteries typically consist of a casing, a cover, and electrode assemblies. The electrode assemblies are installed inside the casing. The cover has an injection hole through which electrolyte is injected into the casing. The cover and casing form a sealed space, enclosing the electrode assemblies and other components to prevent electrolyte leakage. Conventional lithium-ion batteries have a lower plastic layer on the cover to insulate and isolate the cover and electrode assemblies. This lower plastic layer usually has a through-hole positioned opposite the injection hole.

[0003] However, during the electrolyte filling process of the aforementioned lithium-ion batteries, the electrolyte enters the casing through the filling hole and through hole without any obstruction. Under high voltage and high speed, the electrolyte impacts the electrode assembly, which can easily cause the electrode plates to bend and shed powder, resulting in excessive internal resistance of the cell. In extreme cases, short circuits may occur, posing a safety hazard. In addition, due to the small filling space, electrolyte overflow is prone to occur during the filling process, leading to production safety issues. Utility Model Content

[0004] The purpose of this invention is to provide a battery cell to solve the safety hazards of lithium-ion batteries during electrolyte filling in the prior art; this invention also provides a battery pack using this battery cell.

[0005] To achieve the above objectives, this utility model provides a battery cell having intersecting first, second, and third directions, and the battery cell includes:

[0006] The shell has a receiving cavity;

[0007] Electrode assembly is disposed in the receiving cavity;

[0008] A cover plate is fixedly connected to the housing and seals the receiving cavity. The cover plate includes a top cover piece and a lower plastic piece fixedly connected to the top cover piece. The top cover piece is provided with an injection hole that penetrates the top cover piece along the first direction.

[0009] The lower plastic includes a body and a contact platform connected to each other. The contact platform includes a side plate and a bottom plate connected to the side plate. The body is fixedly connected to the side plate. Along the first direction, the bottom plate abuts against the electrode assembly. The side plate, the bottom plate, and the top cover plate form a slow-flow cavity. The slow-flow cavity communicates with the injection hole. The injection hole and the bottom plate are arranged opposite to each other along the first direction. The side plate also has an opening. The opening penetrates the side plate along the second direction and / or the third direction. The opening communicates the slow-flow cavity and the receiving cavity.

[0010] In some embodiments, the battery cell further includes a flow-disrupting member disposed in the flow-slowing cavity.

[0011] In some embodiments, the turbulence member includes a protrusion that is fixedly connected to the base plate. The protrusion is located at one end of the base plate near the opening and extends along the second direction or the third direction.

[0012] In some embodiments, the connection between the protrusion and the base plate is further provided with a radius (R-angle).

[0013] In some embodiments, the turbulence member includes a protrusion, which is fixedly connected to the base plate. The protrusion is located at one end of the base plate near the opening, and multiple protrusions are spaced apart along the second direction and / or the third direction.

[0014] In some embodiments, the turbulence-disrupting component includes an annular convex bulge, which is fixedly connected to the base plate. Along the first direction, the annular convex bulge is disposed opposite to the injection hole, and multiple annular convex bulges are provided.

[0015] In some embodiments, the abutment platform further includes a first rib and a second rib, the first rib and the second rib being spaced apart along the second direction or the third direction, and the bottom plate, the side plate, the first rib and the second rib forming the slow-flow cavity.

[0016] In some embodiments, along the second direction or the third direction, the distance between the first rib and the second rib is L mm, and the top cover plate is further provided with a groove extending around the injection hole on the side facing the abutment platform, the outer diameter of the groove being D mm, satisfying: L>D.

[0017] In some embodiments, the abutment platform further includes a third rib, and the third rib is fixedly connected between the first rib and the side plate, and between the second rib and the side plate.

[0018] In some embodiments, the battery cell further includes a protective tape attached to the side of the electrode assembly facing the lower plastic, wherein the side plate having the opening along the first direction covers a portion of the protective tape in the orthogonal projection of the electrode assembly.

[0019] This utility model also provides a battery pack, including the battery cells described in any of the above technical solutions.

[0020] Compared with the prior art, the battery cell and battery pack of this utility model embodiment have the following advantages: the lower plastic of the cover plate is formed by the body and the abutment platform. The side plate of the abutment platform is provided with an opening that connects the slow flow cavity and the receiving cavity. The slow flow cavity is connected to the injection hole. When electrolyte is injected into the receiving cavity through the injection hole, the electrolyte impacts the bottom plate in the first direction. After deceleration in the slow flow cavity, it enters the receiving cavity through the opening in the second or third direction, thereby avoiding direct impact of the electrolyte on the electrode assembly and preventing short circuit of the electrode assembly. In addition, the bottom plate of the abutment platform abuts the electrode assembly in the first direction. While insulating and isolating the electrode assembly from the top cover plate, it can ensure sufficient electrolyte buffer space, prevent electrolyte splashing, reduce the electrolyte flow rate, avoid overflow, and ensure the safety of the battery cell. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a single battery cell of this utility model;

[0022] Figure 2 yes Figure 1 A schematic diagram of the structure of the cover plate of the battery cell;

[0023] Figure 3 yes Figure 2 A cross-sectional view of the lower plastic of the cover plate along the second direction;

[0024] Figure 4 yes Figure 2 A cross-sectional view of the lower plastic cover along a third direction;

[0025] Figure 5 yes Figure 2 A schematic diagram of the structure after the lower plastic is fitted with a baffle component;

[0026] Figure 6 yes Figure 5 A magnified schematic diagram of the lower plastic part when the turbulence-disrupting component is a protrusion;

[0027] Figure 7 yes Figure 5 A magnified schematic diagram of the lower plastic part when the turbulence-disrupting component is a convex point;

[0028] Figure 8 yes Figure 5A magnified schematic diagram of the lower plastic part when the turbulence-disrupting component is an annular convex hull;

[0029] Figure 9 This is a cross-sectional view along a third direction of another embodiment of the battery cell of this utility model;

[0030] Figure 10 yes Figure 9 A magnified view of a portion of battery cell A.

[0031] In the diagram, 1 is the housing, 11 is the receiving cavity, 2 is the electrode assembly, 3 is the cover plate, 31 is the top cover plate, 311 is the injection hole, 312 is the groove, 32 is the lower plastic, 321 is the body, 322 is the abutment platform, 3221 is the bottom plate, 3222 is the side plate, 3223 is the slow flow cavity, 3224 is the opening, 323 is the first rib, 324 is the second rib, 325 is the third rib, 4 is the flow disturbance component, 41 is the protrusion, 42 is the protrusion point, 43 is the annular convex bulge, 44 is the R angle, 5 is the protective tape, Z is the first direction, Y is the second direction, and X is the third direction. Detailed Implementation

[0032] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0033] A preferred embodiment of a battery cell of this utility model is as follows: Figures 1 to 10 As shown, the battery cell includes a housing 1, an electrode assembly 2, and a cover plate 3. The housing 1 is a square aluminum shell, making the battery cell a square battery. The housing 1 has a square receiving cavity 11, and the electrode assembly 2 is disposed in the receiving cavity 11. The cover plate 3 is fixedly connected to the housing 1, and the cover plate 3 can seal the receiving cavity 11 to prevent the electrolyte in the receiving cavity 11 from leaking to the outside.

[0034] Each battery cell has a first direction Z, a second direction Y, and a third direction X that intersect each other. In this embodiment, the first direction Z is the height direction of the battery cell, the second direction Y is the width direction of the battery cell, and the third direction X is the thickness direction of the battery cell. The first direction Z, the second direction Y, and the third direction X are perpendicular to each other.

[0035] The cover plate 3 includes a top cover plate 31 and a lower plastic 32. The lower plastic 32 is fixedly connected to the top cover plate 31. Along the first direction Z, the lower plastic 32 is located on the side of the top cover plate 31 facing the electrode assembly 2. The lower plastic 32 insulates and isolates the top cover plate 31 from the electrode assembly 2 to prevent short circuits after the electrode assembly 2 is electrically connected to the top cover plate 31. The top cover plate 31 is also provided with an injection hole 311, which penetrates the top cover plate 31 along the first direction Z. The injection hole 311 is used to inject electrolyte into the receiving cavity 11 to wet the electrode assembly 2.

[0036] The lower plastic assembly 32 includes a body 321 and a contact platform 322. The body 321 is the main structure of the lower plastic assembly 32. The contact platform 322 is fixedly connected to the body 321 to form an integral unit, and it insulates and isolates the electrode assembly 2 and the top cover plate 31 along the third direction X. The dimension of the contact platform 322 along the first direction Z is larger than the dimension of the body 321 along the first direction Z. In this embodiment, the bottom surface of the contact platform 322 is lower than the bottom surface of the body 321, so that after the cover plate 3 is fixedly connected to the housing 1, the contact platform 322 can contact the electrode assembly 2.

[0037] like Figure 2 , Figure 3 and Figure 4 As shown, the abutment platform 322 includes a side plate 3222 and a base plate 3221 connected to the side plate 3222. The main body 321 is fixedly connected to the side plate 3222, making the abutment platform 322 and the main body 321 an integral structure. Along the first direction Z, the base plate 3221 abuts against the electrode assembly 2. The base plate 3221 can press against the electrode assembly 2 along the first direction Z to prevent the electrode assembly 2 from moving within the housing 1, ensuring that the lower plastic 32 insulates and isolates the top cover plate 3 from the electrode assembly 2.

[0038] The side plate 3222 is a closed structure connected to the edge of the bottom plate 3221. The side plate 3222, the bottom plate 3221, and the top cover plate 3 form a slow-flow cavity 3223, which is connected to the injection hole 311. The injection hole 311 and the bottom plate 3221 are arranged opposite each other along the first direction Z. When electrolyte is injected through the injection hole 311, the electrolyte enters the slow-flow cavity 3223 along the first direction Z. At this time, the electrolyte directly impacts the bottom plate 3221. The bottom plate 3221 blocks the electrolyte, preventing it from directly impacting the electrode assembly 2 and protecting the electrode assembly 2.

[0039] The side plate 3222 is also provided with an opening 3224, which penetrates the side plate 3222 along the second direction Y and / or the third direction X, and connects the slow-flow cavity 3223 and the receiving cavity 11. The electrolyte enters the slow-flow cavity 3223 along the first direction Z, impacts the bottom plate 3221, and changes direction, allowing it to flow along the second direction Y and / or the third direction X through the opening 3224 into the receiving cavity 11, thereby wetting the electrode assembly 2. Since the electrolyte flows out from the opening 3224 along the second direction Y and / or the third direction X, its flow direction is perpendicular to the direction of the electrode assembly 2, and it will not impact the electrode assembly 2.

[0040] In this embodiment, as Figures 3 to 8 As shown, the side plate 3222 has an opening 3224 that extends through the side plate 3222 along the second direction Y. When the electrode liquid flows out of the slow-flow cavity 3223, it flows through the opening 3224 along the second direction Y. In other embodiments, such as Figure 9 and Figure 10 As shown, the side plate 3222 may also have only one opening 3224, which penetrates the side plate 3222 along the third direction X. When the electrolyte flows out of the slow flow cavity 3223, it flows through the opening 3224 along the third direction X. Alternatively, the side plate 3222 may have multiple openings 3224, with some openings 3224 penetrating the side plate 3222 along the second direction Y and others penetrating the side plate 3222 along the third direction X. The electrolyte can simultaneously flow through the openings 3224 from both the second direction Y and the third direction X into the receiving cavity 11.

[0041] In this embodiment, three contact platforms 322 are provided, spaced apart along the second direction Y, and adjacent contact platforms 322 are connected by a body 321. An injection hole 311 is located at the center of the top cover plate 31 along the second direction Y, and is positioned opposite the middle contact platform 322 along the first direction Z, which can increase the electrolyte injection speed. In other embodiments, the injection holes 311 can also be located at both ends of the top cover plate 3 along the second direction Y, and are positioned opposite one of the two contact platforms 322 along the first direction Z.

[0042] The battery cell has the injection hole 311 and the abutment platform 322 of the lower plastic 32 positioned opposite each other along the third direction X. This allows the abutment platform 322 to not only limit the electrode assembly 2 but also block and delay the electrolyte flow. When electrolyte is injected into the receiving cavity 11 through the injection hole 311, the electrolyte impacts the bottom plate 3221 along the first direction Z. After being slowed down in the slow-flow cavity 3223, it enters the receiving cavity 11 through the opening 3224 along the second direction Y or the third direction X. This avoids the electrolyte directly impacting the electrode assembly 2 and preventing short circuits. In addition, the bottom plate 3221 of the abutment platform 322 abuts against the electrode assembly 2 along the first direction Z. This not only insulates and isolates the electrode assembly 2 from the top cover 31 but also ensures sufficient electrolyte buffer space, preventing electrolyte splashing, reducing the electrolyte flow rate, avoiding overflow, and ensuring the safety of the battery cell.

[0043] In some embodiments, the battery cell further includes a flow-disrupting member 4, which is disposed in the flow-slowing cavity 3223.

[0044] like Figure 5 As shown, a flow-delaying component 4 is provided in the slow-flow cavity 3223. When the electrolyte enters the slow-flow cavity 3223 through the injection hole 311, the flow-delaying component 4 has the function of slowing down the flow rate of the electrolyte, so as to prevent the electrolyte from being blocked by the bottom plate 3221 and still moving too fast, thereby reducing the risk of impact on the electrode assembly 2.

[0045] In some embodiments, the turbulence member 4 includes a protrusion 41, which is fixedly connected to the base plate 3221. The protrusion 41 is located at one end of the base plate 3221 near the opening 3224 and extends along the second direction Y or the third direction X.

[0046] like Figure 6 As shown, the flow-delaying component 4 is formed by a protrusion 41 provided at the opening 3224 and extending along the second direction Y or the third direction X. The protrusion 41 is a strip extending along the second direction Y or the third direction X. The two ends of the protrusion 41 are connected to the side plate 3222. After the electrolyte impacts the bottom plate 3221, it changes direction and will first hit the protrusion 41 before flowing out of the opening 3224 when it flows through the opening 3224. The protrusion 41 has the function of slowing down the flow rate of the electrolyte.

[0047] In some embodiments, the connection between the protrusion 41 and the base plate 3221 is further provided with an R-angle 44.

[0048] The radius R44 allows for a smooth transition between the protrusion 41 and the base plate 3221. When the electrolyte flows through the protrusion 41, it changes its flow direction along the radius R44, which can reduce the impact force of the electrolyte on the protrusion 41.

[0049] In some embodiments, the turbulence member 4 includes a protrusion 42, which is fixedly connected to the base plate 3221. The protrusion 42 is located at one end of the base plate 3221 near the opening 3224, and a plurality of protrusions 42 are spaced apart along the second direction Y and / or the third direction X.

[0050] like Figure 7 As shown, the flow-dispersing component 4 is formed by a plurality of protrusions 42 spaced apart along the second direction Y and / or the third direction X. The gap between two adjacent protrusions 42 can provide an electrolyte flow channel, and the protrusions 42 have the function of guiding and diverting the flow. In this embodiment, each protrusion 42 is also provided with an R-angle 44 at the connection between it and the base plate 3221 to reduce the impact force of the electrolyte on the protrusions 42.

[0051] In some embodiments, the turbulence member 4 includes an annular convex 43, which is fixedly connected to the base plate 3221. Along the first direction Z, the annular convex 43 is disposed opposite to the injection hole 311, and multiple annular convex 43s are provided.

[0052] like Figure 8 As shown, the turbulence-disrupting component 4 is formed by annular protrusions 43 distributed on the base plate 3221. Since the annular protrusions 43 and the injection hole 311 are arranged opposite each other along the first direction Z, when the electrolyte is injected into the slow flow cavity 3223 through the injection hole 311, it first impacts the annular protrusions 43 on the base plate 3221 along the first direction Z. The annular protrusions 43 splash and disturb the electrolyte, thereby preventing electrolyte splashing and reducing the flow rate.

[0053] In some embodiments, the abutment platform 322 further includes a first rib 323 and a second rib 324. The first rib 323 and the second rib 324 are spaced apart along a second direction Y or a third direction X. The bottom plate 3221, the side plate 3222, the first rib 323 and the second rib 324 enclose and form a slow-flow cavity 3223.

[0054] like Figures 2 to 8 As shown, the first rib 323 and the second rib 324 can block and guide the electrolyte injected into the slow-flow cavity 3223, so that it flows into the receiving cavity 11 through the opening 3224 on the side plate 3222.

[0055] In some embodiments, along the second direction Y or the third direction X, the distance between the first rib 323 and the second rib 324 is L mm, and the top cover plate 31 is also provided with a groove 312 extending around the injection hole 311 on the side facing the abutment platform 322. The outer diameter of the groove 312 is D mm, satisfying: L>D.

[0056] like Figure 4 As shown, the groove 312 is an annular groove surrounding the injection hole 311. The outer diameter of the groove 312 is the maximum value between the groove walls of the groove 312. The distance L between the first rib 323 and the second rib 324 is greater than the outer diameter D of the groove 312. This ensures that all the electrolyte entering the slow flow cavity 3223 through the injection hole 311 enters between the first rib 323 and the second rib 324, preventing the electrolyte from flowing into other positions of the lower plastic 32 through the gap at the groove 312 and becoming trapped, thus preventing an effective charging and discharging process.

[0057] In some embodiments, the abutment platform 322 further includes a third rib 325, and the third rib 325 is fixedly connected between the first rib 323 and the side plate 3222, and between the second rib 324 and the side plate 3222.

[0058] The third rib 325 connects the first rib 323 and the side plate 3222, and the second rib 324 and the side plate 3222, so that the first rib 323, the second rib 324, the third rib 325 and the entire abutment platform 322 form an integral whole, which increases the overall strength of the abutment platform 322, ensures that the abutment platform 322 effectively presses against the electrode assembly 2, and increases the electrolyte injection space.

[0059] In some embodiments, the battery cell further includes a protective tape 5, which is attached to the side of the electrode assembly 2 facing the lower plastic 32. Along the first direction Z, the side plate 3222 with an opening 3224 covers the portion of the protective tape 5 in the orthogonal projection of the electrode assembly 2.

[0060] like Figure 1As shown, protective tape 5 is attached to the side of the electrode assembly 2 facing the lower plastic 32, and the protective tape 5 covers the projection of the side plate 3222 with the opening 3224. This ensures that the surface of the electrode assembly 2 located at the opening 3224 is covered by the protective tape 5, preventing it from being washed away by the electrolyte flowing out of the opening 3224 and further improving the safety performance of the battery cell. In this embodiment, the protective tape 5 is wrapped around the electrode assembly 2, and the protective tape 5 is wrapped along the second direction Y for at least a certain distance to ensure that the electrolyte flows out of the opening 3224 and impacts the protective tape 5 first.

[0061] This utility model also provides a preferred embodiment of a battery pack, including a battery cell. The specific structure of the battery cell is the same as that of the battery cell described in any of the above embodiments, and will not be repeated here.

[0062] In summary, this utility model embodiment provides a battery cell and a battery pack. The lower plastic of the cover plate is formed by the body and the abutment platform. An opening is provided on the side plate of the abutment platform to connect the slow flow cavity and the receiving cavity. The slow flow cavity is connected to the injection hole. When electrolyte is injected into the receiving cavity through the injection hole, the electrolyte impacts the bottom plate in the first direction. After deceleration in the slow flow cavity, it enters the receiving cavity through the opening in the second or third direction. This avoids the electrolyte directly impacting the electrode assembly and prevents short circuits in the electrode assembly. In addition, the bottom plate of the abutment platform abuts the electrode assembly in the first direction. While insulating and isolating the electrode assembly from the top cover plate, it can ensure sufficient electrolyte buffer space, prevent electrolyte splashing, reduce the electrolyte flow rate, avoid overflow, and ensure the safety of the battery cell.

[0063] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A battery cell, characterized in that, The battery cell has a first direction, a second direction, and a third direction that intersect each other in pairs, and the battery cell includes: The shell has a receiving cavity; Electrode assembly is disposed in the receiving cavity; A cover plate is fixedly connected to the housing and seals the receiving cavity. The cover plate includes a top cover piece and a lower plastic piece fixedly connected to the top cover piece. The top cover piece is provided with an injection hole that penetrates the top cover piece along the first direction. The lower plastic includes a body and a contact platform connected to each other. The contact platform includes a side plate and a bottom plate connected to the side plate. The body is fixedly connected to the side plate. Along the first direction, the bottom plate abuts against the electrode assembly. The side plate, the bottom plate, and the top cover plate form a slow-flow cavity. The slow-flow cavity communicates with the injection hole. The injection hole and the bottom plate are arranged opposite to each other along the first direction. The side plate also has an opening. The opening penetrates the side plate along the second direction and / or the third direction. The opening communicates the slow-flow cavity and the receiving cavity.

2. The battery cell according to claim 1, characterized in that, The battery cell also includes a flow-disrupting component, which is disposed in the flow-slowing cavity.

3. The battery cell according to claim 2, characterized in that, The turbulence-disrupting component includes a protrusion, which is fixedly connected to the base plate. The protrusion is located at one end of the base plate near the opening and extends along the second direction or the third direction.

4. The battery cell according to claim 3, characterized in that, The connection between the protrusion and the base plate is also provided with a radius (R-angle).

5. The battery cell according to claim 2, characterized in that, The turbulence-disrupting component includes protrusions, which are fixedly connected to the base plate. The protrusions are located at one end of the base plate near the opening, and multiple protrusions are spaced apart along the second direction and / or the third direction.

6. The battery cell according to claim 2, characterized in that, The turbulence-disrupting component includes an annular protrusion, which is fixedly connected to the base plate. Along the first direction, the annular protrusion is disposed opposite to the injection hole, and multiple annular protrusions are provided.

7. The battery cell according to any one of claims 1-6, characterized in that, The abutment platform further includes a first rib and a second rib, the first rib and the second rib are spaced apart along the second direction or the third direction, and the bottom plate, the side plate, the first rib and the second rib enclose the slow flow cavity.

8. The battery cell according to claim 7, characterized in that, Along the second direction or the third direction, the distance between the first rib and the second rib is L mm. The top cover plate is also provided with a groove extending around the injection hole on the side facing the abutment platform. The outer diameter of the groove is D mm, satisfying: L>D.

9. The battery cell according to claim 7, characterized in that, The abutment platform also includes a third rib, and the third rib is fixedly connected between the first rib and the side plate, and between the second rib and the side plate.

10. The battery cell according to any one of claims 1-6, characterized in that, The battery cell also includes a protective tape, which is attached to the side of the electrode assembly facing the lower plastic. Along the first direction, the side plate with the opening covers a portion of the protective tape in the orthogonal projection of the electrode assembly.

11. A battery pack, characterized in that, Includes the battery cell as described in any one of claims 1-10.

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