Cylindrical lithium ion battery

Abstract

The utility model discloses a cylindrical lithium ion battery which comprises a steel shell, a battery cell is arranged in the steel shell, the upper end of the steel shell is connected with a cover cap, at least three annular rings are arranged on the inner wall of the steel shell, and each annular ring comprises a protruding part which abuts against the outer side wall of the battery cell. According to the utility model, the annular ring is arranged on the inner wall of the steel shell, the annular ring comprises the convex part which is propped against the outer side wall of the battery cell, and the convex part is propped against the outer side wall of the battery cell, so that the shaking degree of the battery cell in the steel shell can be effectively reduced, and the use reliability in a vibration environment is improved; the functional layer is attached to the surface of the protruding part, is made of the waterborne polyurethane high polymer material, has high porosity and can absorb electrolyte, the thickness of the functional layer is increased after the functional layer absorbs the electrolyte, the battery cell is limited again, meanwhile, more electrolyte can be stored, electrolyte consumption of the battery cell in the circulation process can be supplemented in time, and the service life of the battery cell is prolonged. And electrolyte required by long circulation is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium - ion batteries, and particularly relates to a cylindrical lithium - ion battery. Background Art

[0002] Lithium - ion batteries currently have the advantages of high energy, long service life, low self - discharge rate, light weight, environmental protection, etc., and are widely used in mobile phones, laptop computers, power tools, electric vehicles, street lamps, backup power supplies, navigation lights, and household small appliances, etc.

[0003] In the prior art, to facilitate the assembly of cylindrical lithium - ion batteries, the outer diameter of the battery core is often smaller than the inner diameter of the steel shell, that is, there is a gap between the battery core and the steel shell. Positive and negative electrode tabs for leading out the current of the battery core are connected to the electrode tabs of the battery core. Under vibration conditions, due to the gap between the battery core and the steel shell, the battery core constantly shakes in the steel shell, easily causing the positive and negative electrode tabs to break, resulting in the failure of the cylindrical lithium - ion battery, and even affecting the use safety due to the short - circuit contact of the positive and negative electrode tabs.

[0004] In addition, the 3C certification requires that lithium - ion batteries circulating in the market must pass the heavy - object impact test 100%. In fact, the passing rate of the heavy - object impact of lithium - ion batteries is very low. The main reason is that when the battery core is impacted by a heavy object, it deforms, the separator cracks, resulting in the contact of the positive and negative electrode plates, rapid heat generation, and thermal runaway.

[0005] Secondly, during the later cyclic operation of the battery core, the electrolyte is consumed, and the electrolyte required to maintain subsequent cycles is lacking, resulting in a significant decline in the cyclic performance of the battery core.

[0006] Furthermore, the moisture in the battery core will also affect the cyclic performance of the battery core. Summary of the Utility Model

[0007] The purpose of the utility model is to provide a cylindrical lithium - ion battery to solve the problems raised in the above background art. A cylindrical lithium - ion battery provided by the utility model has the characteristic of preventing the battery core from constantly shaking in the steel shell.

[0008] To achieve the above purpose, the utility model provides the following technical solution: A cylindrical lithium - ion battery, including a steel shell, a battery core is arranged inside the steel shell, a cap is connected to the upper end of the steel shell, and at least three annular rings are sequentially arranged on the inner wall of the steel shell from top to bottom. The annular ring includes a protruding portion that abuts against the outer side wall of the battery core.

[0009] To provide positioning for the annular ring and a fixing surface, further, annular grooves corresponding to the annular rings are arranged on the inner wall of the steel shell.

[0010] Further, the contact surface between the protruding portion and the battery core is in an arc - shaped or flat - shaped structure.

[0011] In order to quickly conduct the internal heat to the outside in a timely manner, effectively improve the safety performance of the battery cell, and play a buffering role when the battery cell is impacted by a heavy object, reduce the deformation of the battery cell, thereby improving the qualification rate of heavy object impact. Further, the annular ring is made of heat-conducting silica gel material.

[0012] In order to limit the battery cell again, store more electrolyte, timely supplement the electrolyte consumption of the battery cell during the cycle, concentrate the moisture inside the battery cell in the functional layer, and further improve the safety of the battery cell. Further, a functional layer with an increased thickness after absorbing the electrolyte is attached to the surface of the protruding part. The functional layer is a water-based polyurethane polymer material. The porosity of the functional layer is 40% - 80%, the average pore diameter is 5μm - 50μm, and the thickness is 45 - 80um.

[0013] In order to facilitate the assembly of the battery cell and the steel shell. Further, the thickness of the protruding part and the functional layer is less than the gap between the battery cell and the steel shell.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] 1. The present utility model provides an annular ring on the inner wall of the steel shell. The annular ring includes a protruding part that abuts against the outer side wall of the battery cell. By abutting the protruding part against the outer side wall of the battery cell, the degree of shaking of the battery cell in the steel shell can be effectively reduced, and the reliability of use in a vibrating environment can be improved;

[0016] 2. The annular ring of the present utility model is made of heat-conducting silica gel material, which has good heat conductivity and elasticity. On the one hand, when the battery cell generates heat, it can quickly conduct the internal heat to the outside in a timely manner, effectively improving the safety performance of the battery cell. On the other hand, it can play a buffering role when the battery cell is impacted by a heavy object, reduce the deformation of the battery cell, thereby improving the qualification rate of heavy object impact;

[0017] 3. A functional layer is attached to the surface of the protruding part of the present utility model. The functional layer is a water-based polyurethane polymer material, which has a high porosity and can absorb the electrolyte. After absorbing the electrolyte, its thickness increases, which limits the battery cell again, and at the same time can store more electrolyte, and can timely supplement the electrolyte consumption of the battery cell during the cycle, ensuring the electrolyte required for long cycles;

[0018] 4. The functional layer of the present utility model also has excellent hydrophilicity, which can concentrate the moisture inside the battery cell in the functional layer, further reduce the moisture inside the battery cell, and significantly improve the cycle performance of the battery cell;

[0019] 5. The functional layer of the present utility model also has good elasticity, which can cooperate with the annular ring to play a buffering role when the battery cell is impacted by an external force, further improving the safety of the battery cell. Description of the Drawings

[0020] Figure 1 is a schematic structural view of the present utility model;

[0021] Figure 2 is a partial sectional structural view of the annular ring of the present utility model;

[0022] Figure 3 is a partial sectional structural view of the annular ring in another embodiment of the present utility model;

[0023] In the figure: 1, steel shell; 2, cap; 3, battery cell; 4, annular ring; 41, protruding portion; 42, functional layer; 5, annular groove. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0025] Embodiment 1

[0026] Please refer to Figure 1-2 , the present utility model provides the following technical solutions: a cylindrical lithium-ion battery, including a steel shell 1, a battery cell 3 is provided inside the steel shell 1, a cap 2 is connected to the upper end of the steel shell 1, and at least three annular rings 4 are sequentially provided on the inner wall of the steel shell 1 from top to bottom. The annular ring 4 includes a protruding portion 41 that abuts against the outer side wall of the battery cell 3.

[0027] By adopting the above technical solutions, the present utility model is provided with an annular ring 4 on the inner wall of the steel shell 1. The annular ring 4 includes a protruding portion 41 that abuts against the outer side wall of the battery cell 3. By abutting the protruding portion 41 against the outer side wall of the battery cell 3, the degree of shaking of the battery cell 3 in the steel shell 1 can be effectively reduced, and the reliability of use in a vibrating environment can be improved.

[0028] Specifically, an annular groove 5 corresponding to the annular ring 4 is provided on the inner wall of the steel shell 1.

[0029] By adopting the above technical solutions, it is used for the positioning of the annular ring 4 and provides a fixing surface.

[0030] Specifically, the contact surface between the protruding portion 41 and the battery cell 3 is a circular arc structure.

[0031] Specifically, the annular ring 4 is made of heat-conducting silicone material.

[0032] By adopting the above technical solutions, it has good thermal conductivity and elasticity. On the one hand, when the battery cell 3 generates heat, the internal heat can be quickly conducted to the outside in a timely manner, effectively improving the safety performance of the battery cell 3. On the other hand, it can play a buffering role when the battery cell 3 is impacted by a heavy object, reducing the deformation of the battery cell 3, thereby improving the qualified rate of heavy object impact.

[0033] Example 2

[0034] The difference between this embodiment and Embodiment 1 is as follows: Specifically, a functional layer 42 with an increased thickness after absorbing the electrolyte is attached to the surface of the protruding portion 41. The functional layer 42 is a waterborne polyurethane polymer material. The porosity of the functional layer 42 is 40% - 80%, the average pore diameter is 5μm - 50μm, and the thickness is 45 - 80um.

[0035] By adopting the above technical solutions, the functional layer 42 of the waterborne polyurethane polymer material has a high porosity and can absorb the electrolyte. After absorbing the electrolyte, its thickness increases, and it limits the battery cell 3 again. At the same time, it can store more electrolyte and can timely supplement the electrolyte consumption of the battery cell 3 during the cycle, ensuring the electrolyte required for long cycles; the functional layer 42 of the waterborne polyurethane polymer material also has excellent hydrophilicity, which can concentrate the moisture inside the battery cell 3 in the functional layer 42, further reducing the moisture inside the battery cell 3 and significantly improving the cycle performance of the battery cell 3; the functional layer 42 of the waterborne polyurethane polymer material also has good elasticity and can cooperate with the annular ring 4 to play a buffering role when the battery cell 3 is impacted by an external force, further improving the safety of the battery cell 3.

[0036] Example 3

[0037] Please refer to Figure 3 , the difference between this embodiment and Embodiment 1 is as follows: Specifically, the contact surface between the protruding portion 41 and the battery cell 3 is a planar structure.

[0038] Example 4

[0039] The difference between this embodiment and Embodiment 1 is as follows: Specifically, the thickness of the protruding portion 41 and the functional layer 42 is slightly smaller than the gap between the battery cell 3 and the steel shell 1. In this embodiment, the outer diameter of the battery cell 3 is 20.35mm, the inner diameter of the steel shell 1 is 20.55mm, and the thickness of the protruding portion 41 and the functional layer 42 is 0.15mm. The protruding portion 41 refers to the part protruding from the inner wall of the steel shell 1.

[0040] By adopting the above technical solutions, it is convenient for the assembly of the battery cell 3 and the steel shell 1.

[0041] In summary, the utility model is provided with an annular ring 4 on the inner wall of the steel shell 1, and the annular ring 4 includes a protrusion 41 abutting against the outer wall of the battery core 3. The protrusion 41 abuts against the outer wall of the battery core 3, which can effectively reduce the degree of shaking of the battery core 3 in the steel shell 1 and improve the reliability of use in a vibrating environment; the annular ring 4 of the utility model is made of thermal conductive silicone material, which has good thermal conductivity and elasticity. On the one hand, when the battery core 3 generates heat, it can quickly conduct the internal heat to the outside in time, effectively improving the safety performance of the battery core 3. On the other hand, it can play a buffering role when the battery core 3 is hit by a heavy object, reduce the deformation of the battery core 3, and thus improve the qualified rate of heavy object impact; the surface of the protrusion 41 of the utility model is provided with a functional The energy layer 42 and the functional layer 42 are aqueous polyurethane polymer materials with high porosity and can absorb electrolyte. After absorbing the electrolyte, the thickness increases, and the battery cell 3 is limited again. At the same time, more electrolyte can be stored, and the electrolyte consumption of the battery cell 3 during the cycle can be replenished in time to ensure the electrolyte required for long cycle. The functional layer 42 of the utility model also has excellent hydrophilicity, and can concentrate the moisture inside the battery cell 3 in the functional layer 42, so that the moisture inside the battery cell 3 is further reduced, and the cycle performance of the battery cell 3 is significantly improved. The functional layer 42 of the utility model also has good elasticity, and can cooperate with the annular ring 4 to play a buffering role when the battery cell 3 is impacted by external force, so as to further improve the safety of the battery cell 3.

[0042] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cylindrical lithium-ion battery, comprising a steel shell, an electric core is arranged inside the steel shell, and a cap is connected to the upper end of the steel shell, and is characterized in that: On the inner wall of the steel shell, at least three annular rings are successively arranged from top to bottom, and the annular ring includes a protruding portion abutting against the outer side wall of the battery cell.

2. A cylindrical lithium-ion battery according to claim 1, characterized in that: An annular groove corresponding to the annular ring is arranged on the inner wall of the steel shell.

3. A cylindrical lithium-ion battery according to claim 1, characterized in that: The contact surface between the protruding portion and the battery cell is an arc-shaped or flat structure.

4. A cylindrical lithium-ion battery according to claim 1, characterized in that: The annular ring is made of heat-conducting silica gel material.

5. A cylindrical lithium-ion battery according to claim 1, characterized in that: A functional layer with an increased thickness after absorbing the electrolyte is attached to the surface of the protruding portion.

6. A cylindrical lithium-ion battery according to claim 5, characterized in that: The functional layer is a waterborne polyurethane polymer material.

7. A cylindrical lithium-ion battery according to claim 6, characterized in that: The porosity of the functional layer is 40% - 80%, the average pore diameter is 5μm - 50μm, and the thickness is 45 - 80um.

8. A cylindrical lithium-ion battery according to claim 5, characterized in that: The thickness of the protruding portion and the functional layer is less than the gap between the battery cell and the steel shell.

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