Cylindrical battery

Abstract

The utility model provides a cylindrical battery. The cylindrical battery comprises a shell, a cover plate and a roll core, an opening is formed in the top of the shell, and a supporting rod extending to the top is arranged at the bottom of the shell. The cover plate is hermetically connected with the opening; the supporting rod is sleeved with the roll core, the bottom and the top of the roll core are insulated from the bottom of the shell and the cover plate respectively, and an insulation gap is formed between the outer wall of the roll core and the inner wall of the shell. The supporting rod extending to the top is arranged at the bottom of the shell, and the roll core is arranged on the supporting rod in a sleeving manner, so that the roll core is supported, stress relaxation of a roll core pole piece in the use process is prevented, lithium precipitation caused by collapse and loose fitting of the roll core inner ring pole piece after expansion is prevented, and the stability and the reliability of the battery are improved; and the insulation gap is arranged between the outer wall of the roll core and the inner wall of the shell, so that the insulation between the roll core and the shell is ensured, the heat dissipation is enhanced, and the temperature rise of the battery is reduced.

Description

Technical Field

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

[0002] Lithium ions are widely used in life, and cylindrical batteries have also developed rapidly. At present, in order to facilitate the packing and grouping of cylindrical batteries, the size is getting larger and larger, the capacity is getting higher and higher, and the cycle requirements and rate requirements are also getting higher and higher. However, high-rate discharge of large-size cylindrical batteries will face the problem of high temperature rise. The high temperature will further cause an increase in side reactions inside the battery, consume the electrolyte and generate a large amount of gas, resulting in lithium deposition on the electrode plates inside the battery, etc., and then the cycle performance will decline.

[0003] Moreover, when the cylindrical battery is produced, the core is wound with a cylindrical winding needle, and there will be a central hole in the middle of the core. Due to the expansion of the positive and negative electrode plates during the charge and discharge process, the stress of the electrode plates will relax in the inner circle during the cycle, resulting in poor contact and bonding between the positive and negative electrodes, and then lithium deposition at the head of the inner circle of the core. Summary of the Utility Model

[0004] In view of this, the utility model provides a cylindrical battery to solve the technical problem that during the charge and discharge process, the positive and negative electrode plates will expand, resulting in stress relaxation of the electrode plates, poor contact and bonding between the positive and negative electrodes, and then lithium deposition at the head of the inner circle of the core as mentioned in the above background art.

[0005] The technical solution of the utility model is realized as follows:

[0006] The utility model provides a cylindrical battery, including a housing, a cover plate and a core, wherein:

[0007] An opening is provided at the top of the housing, and a support rod extending to the top is provided at the bottom;

[0008] The cover plate is sealingly connected to the opening;

[0009] The core is sleeved on the support rod, and is insulated from the bottom of the housing and the cover plate at the bottom and top respectively, and an insulating gap is provided between the outer wall of the core and the inner wall of the housing.

[0010] On the basis of the above technical solution, preferably, the support rod and the housing are integrally formed.

[0011] On the basis of the above technical solution, preferably, the support rod is axially provided with heat dissipation holes penetrating through the bottom of the housing.

[0012] On the basis of the above technical solution, preferably, an insulating pad is further included, and the insulating pad is sleeved on the support rod and is located between the bottom of the housing and the bottom of the core.

[0013] Based on the above technical solutions, preferably, the cover plate includes a cover plate body and a plastic layer. The cover plate body is hermetically connected to the opening, and the plastic layer is located on the side of the cover plate body facing the core, and is used to press against the top of the core.

[0014] Based on the above technical solutions, preferably, a positioning hole is provided at the center of the cover plate body, and the positioning hole is connected to the top of the support rod.

[0015] Based on the above technical solutions, preferably, the cover plate further includes a positive electrode column and a negative electrode column provided on the cover plate body. The positive electrode column is connected to the positive electrode tab of the core, and the negative electrode column is connected to the negative electrode tab of the core.

[0016] Based on the above technical solutions, preferably, the cover plate further includes a liquid injection hole provided on the cover plate body, and a buffer hole is provided on the side of the liquid injection hole away from the core.

[0017] Based on the above technical solutions, preferably, a reinforcing column is provided on the side of the liquid injection hole close to the core, and the reinforcing column is located outside the liquid injection hole.

[0018] Based on the above technical solutions, preferably, a hollowed-out part is provided inside the reinforcing column.

[0019] The cylindrical battery of the present invention has the following beneficial effects compared with the prior art:

[0020] (1) By providing a support rod extending from the bottom to the top of the housing, the core is sleeved on the support rod to support the core, prevent stress relaxation of the core electrode sheet during use, prevent the inner ring electrode sheet of the core from expanding and collapsing and not fitting tightly, resulting in lithium deposition, and improve the stability and reliability of the battery; and there is an insulating gap between the outer wall of the core and the inner wall of the housing, which can enhance heat dissipation while ensuring insulation between the core and the housing, and reduce the temperature rise of the battery.

[0021] (2) By integrally forming the support rod and the housing, the support rod and the housing bear the force together, improving the support strength of the support rod, thereby further preventing stress relaxation of the core electrode sheet during use and improving the reliability of the device.

[0022] (3) By providing heat dissipation holes axially through the bottom of the housing on the support rod, the heat dissipation effect on the middle part of the core can be improved, avoiding excessive temperature rise of the battery, avoiding high temperature and then causing an increase in side reactions inside the battery, which will consume the electrolyte and generate a large amount of gas, resulting in problems such as lithium deposition on the internal electrode sheet of the battery and thus a decline in the cycle performance, and improving the stability of the battery.

[0023] (4) It is sleeved on the support rod through the insulating gasket and is located between the bottom of the housing and the bottom of the core, so as to insulate between the bottom of the core and the bottom of the housing, improving the reliability and stability of the battery;

[0024] (5) The connection between the cover plate and the housing is realized by sealing the cover plate body to the opening; the plastic layer is located on one side of the cover plate body facing the core and is used to press against the top of the core, so as to insulate between the top of the core and the cover plate, improving the reliability and stability of the battery. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 It is an exploded view of the cylindrical battery of the present invention;

[0027] Figure 2 It is a cross-sectional view of the housing of the present invention;

[0028] Figure 3 It is a three-dimensional view of the cover plate of the present invention Figure 1 ;

[0029] Figure 4 It is a three-dimensional view of the cover plate of the present invention Figure 2 .

[0030] Description of the reference numerals in the drawings: 1 - housing, 2 - cover plate, 3 - core, 4 - insulating gasket;

[0031] 11 - opening, 12 - support rod, 121 - heat dissipation hole;

[0032] 21 - cover plate body, 211 - positioning hole, 22 - plastic layer, 23 - positive electrode post, 24 - negative electrode post, 25 - liquid injection hole, 26 - buffer hole, 27 - strengthening post, 271 - hollowed-out part;

[0033] 31 - positive electrode tab, 32 - negative electrode tab, 33 - center hole. Detailed Embodiments

[0034] Next, in combination with the embodiments of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described. 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 of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present utility model.

[0035] Referring to Figures 1 - 4 As shown, an embodiment of the present utility model provides a cylindrical battery, including a housing 1, a cover plate 2, and a wound core 3, where:

[0036] The top of the housing 1 is provided with an opening 11, and a support rod 12 extending to the top is provided at the bottom; the housing 1 is a hollow structure, the top of the housing 1 is open, and the bottom is sealed;

[0037] The cover plate 2 is hermetically connected to the opening 11; the connection here is by welding;

[0038] The wound core 3 is sleeved on the support rod 12, and the bottom and top are respectively insulated from the bottom of the housing 1 and the cover plate 2. An insulating gap is provided between the outer wall of the wound core 3 and the inner wall of the housing 1. After the wound core 3 is wound and formed, a central hole 33 is formed along the axial direction, and the support rod 12 is sleeved in the central hole 33.

[0039] For the cylindrical battery provided in this embodiment, by providing a support rod 12 extending to the top at the bottom of the housing 1, and the wound core 3 is sleeved on the support rod 12, the wound core 3 is supported to prevent stress relaxation of the wound core 3 electrodes during use, and to prevent the inner ring electrodes of the wound core 3 from expanding and collapsing and not fitting tightly, resulting in lithium deposition, thereby improving the stability and reliability of the battery; and an insulating gap is provided between the outer wall of the wound core 3 and the inner wall of the housing 1, which can enhance heat dissipation while ensuring insulation between the wound core 3 and the housing 1, and reduce the temperature rise of the battery.

[0040] In some embodiments, the support rod 12 and the housing 1 are integrally formed. By integrally forming the support rod 12 and the housing 1, the support rod 12 and the housing 1 bear the force together, improving the support strength of the support rod 12, thereby further preventing stress relaxation of the wound core 3 electrodes during use and improving the reliability of the device.

[0041] In some embodiments, the support rod 12 is axially provided with heat dissipation holes 121 penetrating the bottom of the housing 1. By axially providing heat dissipation holes 121 in the support rod 12 that penetrate the bottom of the housing 1, the heat dissipation effect in the middle of the wound core 3 can be improved, avoiding excessive temperature rise of the battery, and avoiding the problem that high temperature will cause an increase in internal side reactions of the battery, consume the electrolyte and generate a large amount of gas, resulting in lithium deposition on the electrodes inside the battery and further reducing the cycle performance, thereby improving the stability of the battery.

[0042] In some embodiments, the cylindrical battery further includes an insulating pad 4, which is sleeved on the support rod 12 and located between the bottom of the housing 1 and the bottom of the winding core 3. By sleeving the insulating pad 4 on the support rod 12 and locating it between the bottom of the housing 1 and the bottom of the winding core 3, insulation between the bottom of the winding core 3 and the bottom of the housing 1 is achieved, improving the reliability and stability of the battery.

[0043] In some embodiments, the cover plate 2 includes a cover plate body 21 and a plastic layer 22. The cover plate body 21 is sealingly connected to the opening 11, and the plastic layer 22 is located on the side of the cover plate body 21 facing the winding core 3 and is used to press against the top of the winding core 3. The cover plate body 21 is a stepped cylinder. After the cover plate body 21 is closed on the housing 1, the outer edge of the cover plate body 21 is sealingly welded to the opening 11 to realize the connection between the cover plate 2 and the housing 1; by having the plastic layer 22 located on the side of the cover plate body 21 facing the winding core 3 and used to press against the top of the winding core 3, insulation between the top of the winding core 3 and the cover plate 2 is achieved, improving the reliability and stability of the battery.

[0044] In some embodiments, a positioning hole 211 is provided at the center of the cover plate body 21, and the positioning hole 211 is connected to the top of the support rod 12. By providing the positioning hole 211 at the center of the cover plate body 21, when closing the cover plate 2, it can be aligned with the support rod 12 through the positioning hole 211, enabling rapid positioning of the cover plate body 21, and the installation is relatively convenient and fast; subsequently, by welding the edge of the positioning hole 211 to the outer wall of the support rod 12, the connection between the cover plate body 21 and the support rod 12 can be realized, making the integrity of the cover plate body 21, the support rod 12, and the housing 1 better, and they bear force together, improving the reliability and stability of the battery.

[0045] In some embodiments, the cover plate 2 further includes a positive electrode column 23 and a negative electrode column 24 provided on the cover plate body 21. One end of the positive electrode column 23 close to the winding core 3 is connected to the positive electrode tab 31 of the winding core 3, and one end of the negative electrode column 24 close to the winding core 3 is connected to the negative electrode tab 32 of the winding core 3. After sleeving the winding core 3 on the support rod 12 and placing it in the housing 1, the positive electrode tab 31 of the winding core 3 is welded to the positive electrode column 23, and the negative electrode tab 32 of the winding core 3 is welded to the negative electrode column 24, and then the positive electrode tab 31 and the negative electrode tab 32 of the winding core 3 are bent, and then the cover plate 2 is closed at the opening 11. The positive electrode column 23 and the negative electrode column 24 can be symmetrically arranged on both sides of the positioning hole 211.

[0046] In some embodiments, the cover plate 2 further includes a liquid injection hole 25 provided on the cover plate body 21, and a buffer hole 26 is provided on the side of the liquid injection hole 25 away from the winding core 3. The liquid injection hole 25 is located on one side of the positioning hole 211 and is used for injecting liquid into the battery. A buffer hole 26 is provided on the side of the liquid injection hole 25 away from the winding core 3. The buffer hole 26 is coaxial with the liquid injection hole 25, which can buffer the electrolyte and prevent the electrolyte from overflowing outside the cover plate 2 during liquid injection, thereby improving the reliability and stability of the device.

[0047] In some embodiments, a reinforcing column 27 is provided on the side of the liquid injection hole 25 close to the winding core 3, and the reinforcing column 27 is located outside the liquid injection hole 25. Through the reinforcing column 27 on the side of the liquid injection hole 25 close to the winding core 3, the reinforcing column 27 is located outside the liquid injection hole 25 and is coaxial with the liquid injection hole 25, which can strengthen the position of the liquid injection hole 25 and extend the depth of the liquid injection hole 25, thereby improving the stability of liquid injection.

[0048] In some embodiments, a hollowed-out portion 271 is provided inside the reinforcing column 27. By providing the hollowed-out portion 271 inside the reinforcing column 27, on the premise of ensuring the strength of the reinforcing column 27, the structure of the reinforcing column 27 can be made more lightweight, reducing the weight of the battery and being beneficial to improving the energy density of the battery.

[0049] The working principle of this cylindrical battery is as follows: After the winding core 3 is sleeved on the support rod 12 and placed in the housing 1, the positive electrode tab 31 of the winding core 3 is welded to the positive electrode column 23, and the negative electrode tab 32 of the winding core 3 is welded to the negative electrode column 24. Then, the positive electrode tab 31 and the negative electrode tab 32 of the winding core 3 are bent, the cover plate 2 is covered at the opening 11 of the housing 1, the outer edge of the cover plate body 21 is hermetically welded to the opening 11, and the edge of the positioning hole 211 is welded to the outer wall of the support rod 12 to complete the assembly. Through the support rod 12 extending from the bottom to the top of the housing 1, the winding core 3 is sleeved on the support rod 12 to support the winding core 3, preventing the stress relaxation of the pole pieces of the winding core 3 during use, and preventing the inner ring pole pieces of the winding core 3 from expanding and collapsing and not fitting tightly, resulting in lithium plating, thereby improving the stability and reliability of the battery.

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cylindrical battery, characterized in that: It includes a shell, a cover plate and a winding core, wherein: The shell has an opening at the top and a support rod extending to the top at the bottom; The cover plate is sealed and connected to the opening; The winding core is sleeved on the supporting rod, and the bottom and the top are respectively insulated from the bottom of the shell and the cover plate, and an insulating gap is provided between the outer wall of the winding core and the inner wall of the shell.

2. The cylindrical battery according to claim 1, characterized in that: The support rod is integrally formed with the shell.

3. The cylindrical battery according to claim 1, characterized in that: The support rod is provided with a heat dissipation hole along the axial direction and passes through the bottom of the shell.

4. The cylindrical battery according to claim 3, characterized in that: It also includes an insulating pad, which is sleeved on the support rod and located between the bottom of the shell and the bottom of the winding core.

5. The cylindrical battery according to claim 4, characterized in that: The cover plate includes a cover plate body and a plastic layer. The cover plate body is sealed and connected to the opening. The plastic layer is located on a side of the cover plate body facing the winding core and is used to press against the top of the winding core.

6. The cylindrical battery according to claim 5, characterized in that: A positioning hole is provided at the center of the cover plate body, and the positioning hole is connected to the top of the support rod.

7. The cylindrical battery according to claim 6, characterized in that: The cover plate further includes a positive electrode column and a negative electrode column which are arranged on the cover plate body, wherein the positive electrode column is connected to the positive electrode ear of the winding core, and the negative electrode column is connected to the negative electrode ear of the winding core.

8. The cylindrical battery according to claim 7, characterized in that: The cover plate further comprises a liquid injection hole arranged on the cover plate body, and a buffer hole is arranged outside the liquid injection hole on a side away from the winding core.

9. The cylindrical battery according to claim 8, characterized in that: A reinforcing column is arranged on one side of the liquid injection hole close to the winding core, and the reinforcing column is located outside the liquid injection hole.

10. The cylindrical battery according to claim 9, characterized in that: A hollow portion is arranged in the reinforcing column.

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