Cylindrical battery

Abstract

According to the cylindrical battery provided by the utility model, electrolyte can flow through the first through hole, the second through hole and the third through hole and is injected into the shell so as to infiltrate the battery cell, as the second through hole is formed in the positive pole column, opening formation can be realized after primary liquid injection, and secondary liquid injection is carried out by utilizing the first through hole, the second through hole and the third through hole after opening formation; according to the battery structure, the traditional primary liquid injection can be changed, the secondary liquid injection is realized, the liquid injection efficiency is greatly improved, the secondary liquid injection can enable a pole piece to be better infiltrated by electrolyte, the service life of a battery cell is prolonged, and the service life of the battery cell is prolonged. According to the battery structure, traditional closed formation can be changed, open formation can be realized, gas generated during formation is discharged out of the battery cell, a space is provided for secondary liquid injection, internal pressure is reduced, the safety of a product is improved, the service life of the product is prolonged, and the aluminum plate wraps the upper cover plate through the wrapping edge, so that the stability of the battery structure is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cylindrical battery.

Background Art

[0002] During the preparation of a cylindrical battery, electrolyte needs to be injected. The existing process usually adopts one-time injection, and after injection, the cylindrical battery will be hermetically sealed and then formed, that is, closed-loop formation. The existing battery structure only supports the process of one-time injection and closed-loop formation. The structural stability is poor after encapsulation. One-time injection cannot ensure the wetting effect of the electrode plate by the electrolyte. Moreover, the gas generated during the formation stage cannot be discharged during closed-loop formation.

[0003] In view of this, it is necessary to provide a new type of cylindrical battery to overcome the above defects.

Summary of the Utility Model

[0004] The purpose of the utility model is to provide a cylindrical battery to solve the above technical problems.

[0005] To achieve the above purpose, the utility model provides a cylindrical battery, including a housing with one end open, an electric core housed in the housing, a negative current collector plate, and a positive current collector plate assembly; the negative current collector plate is welded to the negative end face of the electric core, and the positive current collector plate assembly is arranged at the open end of the housing; the positive current collector plate assembly includes a positive current collector plate, a positive electrode post, an aluminum plate, a sealing bead, and an upper cover plate; the positive current collector plate includes a first surface and a second surface opposite to the first surface. The first surface of the positive current collector plate is welded to the positive end face of the electric core. One end of the positive electrode post is welded to the second surface of the positive current collector plate, and the other end of the positive electrode post is welded to the aluminum plate. The upper cover plate is fixed on the aluminum plate. The edge of the aluminum plate extends and bends towards the upper cover plate to form a wrapped edge, and the wrapped edge is fixed on the upper cover plate; a first through hole penetrating the first surface and the second surface is opened at the center of the positive current collector plate. A second through hole penetrating is opened at the center of the positive electrode post. A third through hole penetrating is opened at the center of the aluminum plate. The first through hole, the second through hole, and the third through hole are relatively positioned, and the sealing bead is welded in the second through hole of the positive electrode post.

[0006] In a preferred embodiment, a liquid injection hole is opened at one end of the positive electrode post close to the aluminum plate. The liquid injection hole is communicated with the second through hole, and the diameter of the liquid injection hole gradually decreases in the direction away from the aluminum plate.

[0007] In a preferred embodiment, a welding ring groove is opened at one end of the positive electrode post close to the aluminum plate. The welding ring groove surrounds the liquid injection hole, and the aluminum plate is welded in the welding ring groove.

[0008] In a preferred embodiment, a circular welding wire is further provided at one end of the positive electrode post away from the aluminum plate, and the welding wire forms a circular protrusion on the end face of the positive electrode post.

[0009] In a preferred embodiment, an annular explosion-proof engraved line is provided on the surface of the aluminum plate close to the positive electrode post, and the explosion-proof engraved line surrounds the third through hole of the aluminum plate.

[0010] In a preferred embodiment, the second surface of the positive current collector plate includes a welding area surrounding the first through hole, and the positive electrode post is welded within the welding area.

[0011] In a preferred embodiment, a plurality of reinforcing ribs are provided on the second surface of the positive current collector plate, the plurality of reinforcing ribs are arranged along the radial direction of the positive current collector plate, and one end of the plurality of reinforcing ribs close to the center position of the positive current collector plate abuts against the positive electrode post.

[0012] In a preferred embodiment, the positive current collector plate assembly further includes a sealing ring, and the aluminum plate and the upper cover plate are clamped within the sealing ring.

[0013] Compared with the prior art, for the cylindrical battery provided by the present utility model, the first surface of the positive current collector plate is welded and connected to the positive end face of the battery cell, one end of the positive electrode post is welded on the second surface of the positive current collector plate, the other end of the positive electrode post is welded and connected to the aluminum plate, the upper cover plate is fixed on the aluminum plate, the edge of the aluminum plate extends and bends towards the direction close to the upper cover plate to form a wrapped edge, the wrapped edge is fixed on the upper cover plate, a first through hole penetrating through the first surface and the second surface is provided at the center of the positive current collector plate, a through second through hole is provided at the center of the positive electrode post, a through third through hole is provided at the center of the aluminum plate, and the first through hole, the second through hole, and the third through hole are relatively positioned, so that the electrolyte can flow through the first through hole, the second through hole, and the third through hole and be injected into the shell to soak the battery cell. Since the positive electrode post is provided with the second through hole, formation with an open mouth can be realized after primary liquid injection, and secondary liquid injection is carried out by using the first through hole, the second through hole, and the third through hole after formation with an open mouth. After secondary liquid injection, the sealing bead is welded in the second through hole of the positive electrode post to seal the second through hole. This battery structure can change the traditional primary liquid injection to realize secondary liquid injection, greatly improving the liquid injection efficiency. Secondary liquid injection can enable the electrode sheets to be better soaked by the electrolyte, increasing the service life of the battery cell. This battery structure can change the traditional formation with a closed mouth to realize formation with an open mouth, and discharge the gas generated during formation from the inside of the battery cell, providing space for secondary liquid injection and reducing the internal pressure, increasing the safety and service life of the product. The aluminum plate wraps the upper cover plate through the wrapped edge, improving the structural stability of the battery.

Description of the Drawings

[0014] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the attached drawings required for use in the embodiments. It should be understood that the following attached drawings only show certain embodiments of the present utility model and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related attached drawings can also be obtained based on these attached drawings.

[0015] Figure 1 Structural diagram of the cylindrical battery provided by the present utility model;

[0016] Figure 2 Another structural diagram of the cylindrical battery provided by the present utility model;

[0017] Figure 3 For Figure 2 Enlarged view of part A in

[0018] Figure 4 Exploded structural diagram of the cylindrical battery provided by the present utility model;

[0019] Figure 5 Structural diagram of the positive current collector plate in the cylindrical battery provided by the present utility model;

[0020] Figure 6 Structural diagram of the positive electrode post in the cylindrical battery provided by the present utility model;

[0021] Figure 7 Structural diagram of the aluminum plate in the cylindrical battery provided by the present utility model;

[0022] Figure 8 For Figure 7 Cross-sectional view taken along line A-A in

[0023] Figure 9 Structural diagram of the sealing ring in the cylindrical battery provided by the present utility model.

Specific Embodiments

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the attached drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments. Usually, the components of the embodiments of the present utility model described and shown in the attached drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present utility model provided in the attached drawings is not intended to limit the scope of the present utility model to be protected, but only represents the selected embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0025] Please refer toFigure 1 , which is the structural diagram of the cylindrical battery 100 provided by the present utility model. The cylindrical battery 100 provided by the present utility model has a battery structure that can change the traditional one-time liquid injection to achieve secondary liquid injection, greatly improving the liquid injection efficiency. Moreover, this battery structure can change the traditional closed-circuit formation to achieve open-circuit formation and discharge the gas generated during formation from the inside of the battery cell.

[0026] Please refer to Figure 2 , the cylindrical battery 100 includes a housing 10 with one end open, a battery cell 20 housed in the housing 10, a negative current collector plate 30, and a positive current collector plate assembly 40. The negative current collector plate 30 is welded to the negative end face of the battery cell 20, and the positive current collector plate assembly 40 is disposed at the open end of the housing 10.

[0027] Please also refer to Figure 3 and Figure 4 , the positive current collector plate assembly 40 includes a positive current collector plate 41, a positive electrode post 42, an aluminum plate 43, a sealing bead 44, and an upper cover plate 45. The positive current collector plate 41 includes a first surface 411 and a second surface 412 opposite to the first surface 411. The first surface 411 of the positive current collector plate 41 is welded to the positive end face 202 of the battery cell 20. One end of the positive electrode post 42 is welded to the second surface 412 of the positive current collector plate 41, and the other end of the positive electrode post 42 is welded to the aluminum plate 43. The upper cover plate 45 is fixed on the aluminum plate 43. The edge of the aluminum plate 43 extends and bends towards the upper cover plate to form a wrapped edge 433, and the wrapped edge 433 is fixed on the upper cover plate 45.

[0028] Furthermore, a first through hole 401 penetrating the first surface 411 and the second surface 422 is formed in the center of the positive current collector plate 41. A second through hole 421 penetrating is formed in the center of the positive electrode post 42. A third through hole 431 penetrating is formed in the center of the aluminum plate 43. The first through hole 401, the second through hole 421, and the third through hole 431 are relatively positioned. The first through hole 401, the second through hole 421, and the third through hole 431 are used to inject electrolyte into the housing 10. The sealing bead 44 is welded in the second through hole 421 of the positive electrode post 42, and the sealing bead 44 is used to seal the second through hole 421 after one-time vacuum liquid injection, open-circuit formation, and secondary vacuum liquid injection.

[0029] The cylindrical battery 100 provided by the present utility model has the first surface 411 of the positive current collector plate 41 welded to the positive end face 202 of the battery cell 20. One end of the positive electrode post 42 is welded to the second surface 412 of the positive current collector plate 41, and the other end of the positive electrode post 42 is welded to the aluminum plate 43. The upper cover plate 45 is fixed on the aluminum plate 43. The edge of the aluminum plate 43 extends and bends towards the upper cover plate to form a wrap 433, and the wrap 433 is fixed on the upper cover plate 45. A first through hole 401 penetrating the first surface 411 and the second surface 422 is provided at the center of the positive current collector plate 41. A second through hole 421 penetrating is provided at the center of the positive electrode post 42. A third through hole 431 penetrating is provided at the center of the aluminum plate 43, and the first through hole 401, the second through hole 421, and the third through hole 431 are relatively positioned. The electrolyte can flow through the first through hole 401, the second through hole 421, and the third through hole 431 and be injected into the housing 10 to soak the battery cell 20. Since the second through hole 421 is provided in the positive electrode post 42, open formation can be achieved after the first liquid injection. After the open formation, secondary liquid injection is performed using the first through hole 401, the second through hole 421, and the third through hole 431. After the secondary liquid injection, the sealing bead 44 is welded into the second through hole 421 of the positive electrode post 42 to seal the second through hole 421. This battery structure can change the traditional single liquid injection and achieve secondary liquid injection, greatly improving the liquid injection efficiency. The secondary liquid injection can make the electrode plates better soaked by the electrolyte, increasing the service life of the battery cell. This battery structure can change the traditional closed formation and achieve open formation, and discharge the gas generated during formation from the inside of the battery cell, providing space for secondary liquid injection and reducing the internal pressure, increasing the safety and service life of the product. The aluminum plate 43 wraps the upper cover plate 45 through the wrap 433, improving the structural stability of the battery.

[0030] The housing 10 is a cylindrical steel shell. The housing 10 has a receiving space. The housing 10 includes a bottom surface and an outer peripheral surface connecting the bottom surface, and the bottom surface and the outer peripheral surface enclose the receiving space. The battery cell 20 is received in the receiving space. Specifically, one end of the housing 10 away from the bottom surface is open, and the positive current collector plate assembly 100 is provided at the open end of the housing 10, and the negative current collector plate 30 is provided on the bottom surface.

[0031] The battery cell 20 is cylindrical. The battery cell 20 can specifically be formed by winding electrode plates. The battery cell 20 includes a positive end face and a negative end face opposite to the positive end face. The negative end face of the battery cell is welded to the negative current collector plate 30 to lead out the negative electrode of the cylindrical battery, and the positive end face of the battery cell is welded to the positive current collector plate assembly 40 to lead out the positive electrode of the cylindrical battery.

[0032] Specifically, the negative current collector plate 30 is a circular sheet structure. The negative current collector plate 30 is used to electrically connect the negative electrode end face of the battery cell (such as the negative electrode tab on the negative electrode end face) to the housing 10. A welding boss is provided at the center of the negative current collector plate, and the welding boss is used for welding and fixing to the housing 10. The negative current collector plate 30 is provided with a plurality of reinforcing ribs. The plurality of reinforcing ribs are arranged along the radial direction of the negative current collector plate, and the plurality of reinforcing ribs are arranged around the welding boss. The reinforcing ribs can enhance the overall strength of the negative current collector plate and prevent the current collector plate from being deformed by external force extrusion when the current collector plate is grasped during the production process.

[0033] In this embodiment, the number of the reinforcing ribs is four, and the four reinforcing ribs are symmetrically arranged. Laser slotted lines are provided on both sides of the reinforcing ribs. The laser slotted lines create a stretchable space inside and outside the slotted lines. When the battery cell is subjected to a certain vibration during actual use, the welding joint will not become unsoldered and ineffective. At the same time, the setting of the reinforcing ribs can increase the elastic coefficient inside and outside the slotted lines. A plurality of positioning grooves are also formed at the edge of the negative current collector plate 30. The positioning grooves facilitate the positioning of the incoming material and are convenient for automated production. The number of the positioning grooves is specifically four, and the shape of the positioning grooves is specifically semi-circular.

[0034] Please refer to Figure 5 In some embodiments, the positive current collector plate 41 is a circular sheet structure. The positive current collector plate 41 is used to electrically connect the positive electrode end face of the battery cell (such as the positive electrode tab on the positive electrode end face) to the positive electrode post 42. Specifically, the first through hole 401 is located at the center of the positive current collector plate 41. The second surface of the positive current collector plate 41 includes a welding area 410 surrounding the first through hole 401, and the positive electrode post 42 is welded in the welding area. A plurality of reinforcing ribs 413 are provided on the second surface 412 of the positive current collector plate 41. The plurality of reinforcing ribs are arranged along the radial direction of the positive current collector plate. One end of the plurality of reinforcing ribs close to the center position of the positive current collector plate 41 abuts against the positive electrode post 42. The reinforcing ribs 413 are arranged at positions outside the welding area. The reinforcing ribs 413 are beneficial for positioning during the welding of the positive electrode post and can also enhance the overall strength of the positive current collector plate to prevent the current collector plate from being deformed by external force extrusion when the current collector plate is grasped during the production process.

[0035] In this embodiment, the number of the reinforcing ribs 413 is four, and the four reinforcing ribs 413 are symmetrically arranged. Laser slotted lines 414 are provided on both sides of the reinforcing ribs 413. The laser slotted lines 414 create a stretchable space inside and outside the slotted lines. When the battery cell is subjected to a certain vibration during actual use, the welding joint will not become unsoldered and ineffective. At the same time, the setting of the reinforcing ribs 413 can increase the elastic coefficient inside and outside the slotted lines. A plurality of positioning grooves 415 are also formed at the edge of the positive current collector plate 41. The positioning grooves 415 facilitate the positioning of the incoming material and are convenient for automated production. The number of the positioning grooves 415 is specifically four, and the shape of the positioning grooves 415 is specifically semi-circular.

[0036] Please refer to Figure 6, the positive electrode post 42 is generally cylindrical. A through second through hole 421 is provided in the positive electrode post 42. The second through hole 421 is located at the central position of the positive electrode post. The positive electrode post 42 is located between the positive current collector plate 41 and the aluminum plate 43, and the positive electrode post 42 is used to conduct the positive current collector plate 41 and the aluminum plate 43.

[0037] In some embodiments, a liquid injection hole 422 is provided at one end of the positive electrode post 42 close to the aluminum plate 43. The liquid injection hole 422 communicates with the second through hole 421. The diameter of the liquid injection hole 422 gradually decreases in the direction away from the aluminum plate 43, that is, the liquid injection hole 422 is a tapered liquid injection hole, which is convenient for the automatic liquid injection nozzle of the device to be aligned, and is convenient for the plugging and unplugging actions of the liquid injection and formation processes. The liquid injection hole 422 and the second through hole 421 also play the role of exhausting gas after formation.

[0038] Furthermore, a welding ring groove 423 is provided at one end of the positive electrode post 42 close to the aluminum plate 43. The welding ring groove 423 surrounds the liquid injection hole 422. The aluminum plate 43 is welded in the welding ring groove 423. The aluminum plate 43 is welded in the welding ring groove 423, which can increase the welding area between the aluminum plate 43 and the positive electrode post 42, making the welding more firm and enhancing the structural stability. In some embodiments, a circular welding wire is further provided at one end of the positive electrode post 42 away from the aluminum plate 43. The welding wire forms a circular protrusion 424 on the end face of the positive electrode post 42, which is beneficial for the welding wire to be accurately welded to the welding area 410 of the positive current collector plate 41.

[0039] Please refer to Figure 7 and Figure 8 , the aluminum plate 43 is a circular sheet structure. A through third through hole 431 is provided at the center of the aluminum plate 43. At the same time, the third through hole 431 is also the welding hole of the positive electrode post 42. Through laser welding, the aluminum plate 43 and the positive electrode post 42 can be conducted.

[0040] In some embodiments, an annular explosion-proof engraved line 432 is provided on the surface of the aluminum plate 43 close to the positive electrode post 42. The explosion-proof engraved line surrounds the third through hole 431 of the aluminum plate. Specifically, the explosion-proof engraved line 432 is formed by thinning the thickness through a laser engraving process, reducing the compressive strength here. When the internal pressure reaches a certain level, this place will be broken, and the internal gas will be discharged from the inside of the battery cell. And the explosion-proof engraved line 432 is annular. After the explosion-proof engraved line 432 is broken, the positive electrode post 42 and the aluminum plate 43 are cut off and conducted, which greatly ensures the safety of the battery cell during use.

[0041] The sealing bead 44 is a spherical sealing steel bead. The sealing bead 44 is welded in the second through hole 421 of the positive electrode post 42, and the sealing bead 44 is used to seal the second through hole 421 after primary vacuum liquid injection, open formation, and secondary vacuum liquid injection. Sealing with the sealing steel bead ensures that the gas generated during the operation of the battery cell cannot affect the traditional screw, the electrolyte will not overflow, effectively ensuring the internal environment of the battery cell and extending the service life of the battery cell.

[0042] In the cylindrical battery 100 provided in this embodiment, the positive current collector plate assembly 40 further includes an upper cover plate 45. The upper cover plate 45 is fixed on the aluminum plate 43, and the edge of the upper cover plate 45 is flush with the edge of the aluminum plate 43. The upper cover plate 45 is used to further ensure the battery sealing performance. In some embodiments, the edge of the aluminum plate 43 further extends outward to form a wrapped edge 433. The wrapped edge 433 bends towards the upper cover plate 45 and the bent wrapped edge 433 is fixed on the upper cover plate 45 by laser welding, that is, the edge of the aluminum plate 43 wraps the upper cover plate 45, making the welding of the upper cover plate 45 more firm, capable of reducing the deformation coefficient during the encapsulation of the upper cover plate. The aluminum plate 43 plays a role in conducting the positive electrode post and the upper cover plate and relieving pressure.

[0043] Please refer to Figure 9 , in some embodiments, the positive current collector plate assembly 40 further includes a sealing ring 46. The sealing ring 46 is an annular rubber ring, and the sealing ring 46 has the functions of isolating the positive and negative electrodes and preventing the penetration of the electrolyte. Specifically, the sealing ring 46 includes a top wall 461, a bottom wall 462, and a side wall 463 connecting the top wall 461 and the bottom wall 462. Specifically, both the top wall 461 and the bottom wall 462 are perpendicularly arranged with respect to the side wall 463. The aluminum plate 43 and the upper cover plate 45 are clamped within the sealing ring, that is, clamped between the top wall 461 and the bottom wall 462.

[0044] In this embodiment, the bottom wall 462 is convexly provided with a lower water stop rib 464. After encapsulation, the lower water stop rib has the function of preventing the electrolyte from penetrating from the contact surface between the aluminum plate and the sealing ring. A waterproof groove 460 can be formed between the lower water stop rib 464 and the side wall 463, and the waterproof groove 460 can further prevent the electrolyte from overflowing. The bottom wall 462 also extends in a direction away from the top wall 461 to form a bottom water stop rib 465. After encapsulation, the bottom water stop rib has the function of preventing the electrolyte from penetrating from the contact surface between the steel shell and the sealing ring, further ensuring the battery sealing performance. In other embodiments, the side wall 463 can also be convexly provided with side waterproof ribs to prevent the electrolyte from penetrating from the contact surface between the aluminum plate and the sealing ring.

[0045] The cylindrical battery 100 provided by the present utility model is a battery structure with a pull - off function that can be refilled, formed, and vented twice. This battery structure can change the traditional one - time liquid injection to achieve secondary liquid injection, which can greatly improve the liquid injection efficiency. It can change the traditional closed - type forming to achieve open - type forming, and discharge the gas generated during forming from the inside of the battery core. After encapsulation, this battery structure has reliable sealing. Secondary liquid injection can make the electrode plates better wetted by the electrolyte, increasing the service life of the battery core. Open - type forming can discharge the gas generated during forming from the inside of the battery core, providing space for secondary liquid injection and reducing the internal pressure, increasing the safety and service life of the product. The reliable sealing ensures the safety of the product. Sealing is carried out through a sealing steel ball, ensuring that the gas generated during the operation of the battery core has no impact on the traditional screw, and the electrolyte will not overflow, effectively ensuring the internal environment of the battery core and extending the service life of the battery core.

[0046] The liquid injection process of the cylindrical battery provided based on the above - mentioned embodiment will be elaborated in detail below.

[0047] Primary vacuum liquid injection: Inject the electrolyte into the shell for the first time. The electrolyte flows through the third through - hole, the second through - hole, and the first through - hole in sequence, and the electrolyte wets the battery core inside the shell.

[0048] Open - type forming: Carry out forming under the condition that the second through - hole is not sealed.

[0049] Secondary vacuum liquid injection: Inject the electrolyte into the shell for the second time. The electrolyte flows through the third through - hole, the second through - hole, and the first through - hole in sequence, and the electrolyte wets the battery core inside the shell.

[0050] Sealing: Weld the sealing bead in the second through - hole of the positive electrode post to seal the second through - hole.

[0051] It can be understood that first, primary vacuum liquid injection is carried out. The electrolyte flows through the third through - hole, the second through - hole, and the first through - hole in sequence, and the electrolyte wets the battery core inside the shell. Then, open - type forming is carried out. After forming, the battery is refilled for the second time. Using secondary liquid injection can ensure the effect of wetting the electrode plates by the electrolyte. Open - type forming can discharge the gas generated during forming from the inside of the battery core, providing space for secondary liquid injection and reducing the internal pressure, increasing the safety and service life of the product. Finally, it is sealed with a sealing bead, and the reliable sealing ensures the safety of the product.

[0052] Furthermore, after primary vacuum liquid injection, it also includes:

[0053] Insert a rubber plug into the second through - hole for temporary sealing;

[0054] Subject the temporarily sealed cylindrical battery to high - temperature standing. The environment for high - temperature standing is a dew point of - 45°C and a temperature of 45 ± 2°C, and the time for high - temperature standing is 48 h;

[0055] After standing at high temperature, pull out the rubber plug and then carry out open-circuit formation.

[0056] In this embodiment, the rubber plug is inserted and pulled out at a dew point of -45°C and a temperature of 23 + 3°C in the inner small environment. The temporary seal can prevent the electrolyte from volatilizing during the process of the electrolyte infiltrating the electrode sheet, ensuring the infiltration effect of the electrode sheet.

[0057] Specifically, the injection volume of the first vacuum injection is 85 - 90% of the total injection volume, and the injection time of the first vacuum injection is 50 min; the injection volume of the second vacuum injection is 10 - 15% of the total injection volume, and the injection time of the second vacuum injection is 30 min. By reasonably controlling the injection volume and injection time of the first vacuum injection and the second vacuum injection, the electrode sheet can be better infiltrated by the electrolyte, greatly improving the injection efficiency and increasing the service life of the battery cell.

[0058] Specifically, the environmental parameters of the environment where the first vacuum injection and the second vacuum injection are carried out are: a dew point of -45°C and a temperature of 23 + 3°C in the inner small environment, and a dew point of -30°C and a temperature of 23 ± 3°C in the external environment. Dividing the injection environment into the inner small environment and the external environment and adopting different environmental parameters can ensure the fluidity of the electrolyte, shorten the time for the electrolyte to be absorbed, facilitate the electrolyte infiltration effect and improve the injection efficiency. The dew point of the inner small environment is strictly controlled at -45°C, which can ensure that the electrolyte does not absorb water.

[0059] For open-circuit formation, specifically, after standing for 1 min, charge at a constant current of 0.05C for 120 min, and then charge at a constant current of 0.15C for 90 min to 30% SOC. After open-circuit formation, the first OCV test is carried out.

[0060] Specifically, open-circuit formation is carried out in the above-mentioned inner small environment. During open-circuit formation, the gas generated during formation is discharged from the inside of the battery cell, providing space for the second injection and reducing the internal pressure, increasing the safety and service life of the product. Formation mainly has two functions: one is to enable the active substances in the battery to be converted into substances with normal electrochemical functions through the first charge, and the other is to form an effective passivation film or SEI film on the electrode, mainly the negative electrode. By carrying out formation with reasonable parameters, the battery can be better activated and the electrochemical performance of the battery can be improved.

[0061] The advantages of using small current formation for lithium batteries are mainly reflected in the following aspects:

[0062] Prolonging Battery Life: Trickle forming helps to avoid overcharging and over-discharging, which are two major factors affecting battery life. By controlling the charging current at a lower level, the battery can be maintained in a relatively stable charging state, thereby reducing battery loss and prolonging its service life. Improving Battery Performance: Trickle charging allows lithium ions to deposit more evenly in the electrode material, which helps to improve the battery's performance. In addition, trickle forming is conducive to the formation of a dense and stable solid electrolyte interface (SEI) film, which helps to enhance the battery's stability and performance. Improving Battery Safety: High-current charging often leads to battery overheating and gas emission, increasing the safety risk of the battery. In contrast, the trickle charging method can reduce this risk and make the battery more stable and safe during charging. Optimizing the Battery Forming Process: In the forming process, trickle forming is an important step in lithium battery production. It helps to activate the active substances in the battery and promote the formation of the SEI film. Although the time for trickle forming is longer, it can form a denser and more stable SEI film, which is crucial for improving the battery's cycle stability and prolonging its service life. Adapting to Different Application Scenarios: For devices that require long standby time and high-quality performance, trickle charging and forming are more suitable choices. These devices often have high requirements for battery life and performance, and trickle charging and forming can just meet these needs. Reducing Electrolyte Volatilization: Under low-current conditions, the battery generates less heat, the temperature inside the battery is not much different from the ambient temperature, the speed of gas generated by internal reactions is small, and the gas exhalation is gentle, which helps to reduce the volatilization of the electrolyte. The electrolyte is an important component of the battery, and the reduction of its volatilization helps to maintain the battery's performance and stability. In summary, the benefits of trickle forming of lithium batteries are mainly reflected in prolonging battery life, improving battery performance, improving battery safety, optimizing the battery forming process, adapting to different application scenarios, and reducing electrolyte volatilization. These benefits have made trickle forming widely used and valued in lithium battery production.

[0063] Further, after the cylindrical battery is sealed with a sealing bead, it is cleaned, the sealing bead is dispensed, the welding piece is welded, oil is applied, the trays are assembled, it is static at high temperature for 48 h, the second OCV test is carried out, supplementary charging is performed, it is static at high temperature for 7 days, static at normal temperature for 12 h, and then the third OCV test is carried out before grading, detection and shipment. Specifically, the environment: the environmental control for the overall cleaning of the battery and the previous process steps is 100,000 class, and it is 1,000,000 class afterwards. The supplementary charging process flow includes: after standing for 1 min, constant current and constant voltage charging at 0.2C to 3.65 V, the cut-off current is 0.05C, the time is 240 min, and the supplementary charging is up to 100% SOC.

[0064] In summary, for the cylindrical battery 100 provided by the present utility model, the first surface 411 of the positive current collector plate 41 is welded to the positive end face 202 of the battery cell 20. One end of the positive electrode post 42 is welded to the second surface 412 of the positive current collector plate 41, and the other end of the positive electrode post 42 is welded to the aluminum plate 43. The upper cover plate 45 is fixed on the aluminum plate 43. The edge of the aluminum plate 43 extends and bends towards the upper cover plate to form a wrapped edge 433, and the wrapped edge 433 is fixed on the upper cover plate 45. A first through hole 401 penetrating the first surface 411 and the second surface 422 is provided at the center of the positive current collector plate 41. A second through hole 421 penetrating is provided at the center of the positive electrode post 42. A third through hole 431 penetrating is provided at the center of the aluminum plate 43. The first through hole 401, the second through hole 421, and the third through hole 431 are relatively positioned, and the electrolyte can flow through the first through hole 401, the second through hole 421, and the third through hole 431 and be injected into the housing 10 to soak the battery cell 20. Since the second through hole 421 is provided in the positive electrode post 42, open formation can be achieved after a first injection. After open formation, a second injection is performed using the first through hole 401, the second through hole 421, and the third through hole 431. After the second injection, the sealing bead 44 is welded into the second through hole 421 of the positive electrode post 42 to seal the second through hole 421. This battery structure can change the traditional single injection and achieve double injection, greatly improving the injection efficiency. The double injection can make the electrode plates better soaked by the electrolyte, increasing the service life of the battery cell. This battery structure can change the traditional closed formation and achieve open formation, and discharge the gas generated during formation from the inside of the battery cell, providing space for the second injection and reducing the internal pressure, increasing the safety and service life of the product. The aluminum plate 43 wraps the upper cover plate 45 through the wrapped edge 433, improving the structural stability of the battery.

[0065] The above is only the embodiment of the present utility model, and does not limit the patent scope of the present utility model. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present utility model.

Claims

1. A cylindrical battery, characterized in that: It comprises a shell with an opening at one end, a battery cell contained in the shell, a negative current collector and a positive current collector assembly; the negative current collector is welded to the negative end surface of the battery cell, and the positive current collector assembly is arranged at one end of the shell opening; The positive current collector assembly includes a positive current collector, a positive electrode column, an aluminum plate, a sealing bead and an upper cover plate; the positive current collector includes a first surface and a second surface opposite to the first surface, the first surface of the positive current collector is welded to the positive end surface of the battery cell, one end of the positive electrode column is welded to the second surface of the positive current collector, the other end of the positive electrode column is welded to the aluminum plate, the upper cover plate is fixed to the aluminum plate, the edge of the aluminum plate extends and is bent toward the direction close to the upper cover plate to form a edging, and the edging is fixed to the upper cover plate; a first through hole penetrating the first surface and the second surface is provided at the center of the positive current collector, a second through hole penetrating the first surface and the second surface is provided at the center of the positive electrode column, a third through hole penetrating the first surface and the second surface is provided at the center of the aluminum plate, the first through hole, the second through hole and the third through hole are relatively positioned, and the sealing bead is welded in the second through hole of the positive electrode column.

2. The cylindrical battery according to claim 1, characterized in that: An injection hole is provided at one end of the positive electrode column close to the aluminum plate. The injection hole is connected to the second through hole. The diameter of the injection hole gradually decreases in a direction away from the aluminum plate.

3. The cylindrical battery according to claim 2, characterized in that: A welding ring groove is formed at one end of the positive electrode column close to the aluminum plate. The welding ring groove surrounds the liquid injection hole, and the aluminum plate is welded in the welding ring groove.

4. The cylindrical battery according to claim 1, characterized in that: A circular welding line is also provided at one end of the positive electrode column away from the aluminum plate, and the welding line forms a circular protrusion on the end surface of the positive electrode column.

5. The cylindrical battery according to claim 1, characterized in that: A ring-shaped explosion-proof engraved line is provided on the surface of the aluminum plate close to the positive electrode column, and the explosion-proof engraved line surrounds the third through hole of the aluminum plate.

6. The cylindrical battery according to claim 1, characterized in that: The second surface of the positive current collecting plate includes a welding area surrounding the first through hole, and the positive electrode column is welded in the welding area.

7. The cylindrical battery according to claim 6, characterized in that: A plurality of reinforcing ribs are arranged on the second surface of the positive current collecting disk. The plurality of reinforcing ribs are arranged along the radial direction of the positive current collecting disk. One end of the plurality of reinforcing ribs close to the center of the positive current collecting disk abuts against the positive pole.

8. The cylindrical battery according to any one of claims 1 to 7, characterized in that: The positive electrode current collecting plate assembly further includes a sealing ring, and the aluminum plate and the upper cover plate are clamped in the sealing ring.

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