Cylindrical lithium ion battery structure

Abstract

The invention discloses a cylindrical lithium ion battery structure which comprises a shell, a core package, and a positive electrode connecting piece and a negative electrode connecting piece which are positioned at the positive electrode end and the negative electrode end of the core package, the positive electrode connecting piece is provided with a plurality of positive electrode fusing connecting bodies, and the positive electrode fusing connecting bodies provide resilience force for the movement of the core cladding through elastic deformation; the negative electrode connecting piece is provided with a plurality of negative electrode fusing connecting bodies, and the negative electrode fusing connecting bodies provide resilience force for the movement of the core cladding through elastic deformation; the positive fusing connector and the negative fusing connector can be fused at a high temperature when the core package is in an accident state. According to the structure, the positive connecting piece and the negative connecting piece are designed, the positive fusing connecting body and the negative fusing connecting body are formed respectively, the fusing connecting bodies are used for adapting to the movement problem of the core package, fusing design is achieved, it is guaranteed that the fusing sectional area of the negative electrode is larger than the fusing sectional area of the positive electrode, and it is guaranteed that the positive electrode is fused preferentially; the space utilization rate is improved, and meanwhile the safety can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a cylindrical lithium-ion battery structure. Background Art

[0002] At present, lithium batteries are roughly divided into soft-pack batteries, square batteries and cylindrical batteries according to their structure. With the rapid development of lithium batteries, lithium batteries of various structures have also ushered in new opportunities, such as the cylindrical battery 4680 series. At present, the 4680 series on the market are mostly steel shells, and can obtain high energy density with high nickel ternary system. However, the space of large cylindrical batteries on the market has not been fully utilized, and the safety is not as good as square batteries and soft-pack batteries.

[0003] Therefore, based on the above technical problems, technicians in this field urgently need to develop a cylindrical lithium-ion battery structure. Summary of the invention

[0004] The object of the present invention is to provide a cylindrical lithium-ion battery structure, which improves the space utilization of the cylindrical battery and has high safety.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A cylindrical lithium-ion battery structure of the present invention comprises:

[0007] A shell, wherein a core package is embedded in the shell, and the core package is a cylindrical core package;

[0008] A positive electrode connecting piece and a negative electrode connecting piece located inside the shell and respectively arranged at the positive terminal and the negative terminal of the core package;

[0009] The positive electrode connecting piece is provided with a plurality of positive electrode fusible connectors, and the positive electrode fusible connectors provide resilience for the movement of the core package through elastic deformation;

[0010] The negative electrode connecting piece is provided with a plurality of negative electrode fusible connectors, and the negative electrode fusible connectors provide resilience for the movement of the core package through elastic deformation;

[0011] The positive electrode fusible connector and the negative electrode fusible connector can both be fused at high temperature when the core package is in an accident state.

[0012] Furthermore, the cross-sectional area of ​​the negative electrode fusible link is greater than the cross-sectional area of ​​the positive electrode fusible link.

[0013] Furthermore, the positive electrode of the core package includes:

[0014] A positive electrode column, the lower portion of which is embedded in the shell;

[0015] A positive electrode upper plastic is arranged between the upper part of the positive electrode column and the upper end of the shell, and the positive electrode upper plastic sleeve is arranged outside the positive electrode column;

[0016] A positive electrode lower plastic that matches the portion of the positive electrode column embedded in the shell; and

[0017] The positive electrode connecting piece;

[0018] A sealing ring is arranged between the positive electrode lower plastic and the positive electrode column.

[0019] Furthermore, the positive electrode connecting piece includes:

[0020] positive busbar; and

[0021] A current collecting column located at the center of the positive electrode collecting plate and protruding toward the positive electrode column;

[0022] The plurality of positive electrode fusible connectors are evenly distributed along the circumference of the positive electrode busbar, and one end of the positive electrode fusible connector is connected to the current collecting column, and the other end extends along the radial direction of the positive electrode busbar;

[0023] A first hollow portion is formed between the positive electrode fusible link and the positive electrode busbar.

[0024] Furthermore, the lower end of the positive electrode column is recessed inward to form an inner hole of the positive electrode column;

[0025] The current collecting column is embedded in the inner hole of the positive electrode column.

[0026] Furthermore, the negative electrode end of the core package is provided with the negative electrode connecting sheet and the negative electrode top cover;

[0027] An integrated sealing nail is installed at the center of the negative electrode top cover, the negative electrode connecting sheet and one end of the negative electrode of the core package.

[0028] Furthermore, the negative electrode connecting piece includes:

[0029] a negative electrode connector; and

[0030] A negative electrode collector is formed in the inner area of ​​the negative electrode connector, and an electrolyte inlet hole is opened in the center of the negative electrode collector;

[0031] The negative electrode collector and the negative electrode connector are connected by a plurality of negative electrode fuse connectors uniformly distributed along the circumference of the negative electrode connector;

[0032] The side surface of the negative electrode fusible connector is a second hollow portion.

[0033] Furthermore, one end of the negative electrode fuse connector is connected to the negative electrode collector, and the other end is connected to the negative electrode connector, and the two are arranged in an inclined structure.

[0034] Furthermore, the negative electrode top cover comprises:

[0035] a top cover connector connected to the negative electrode connector; and

[0036] A liquid injection hole is formed at the center of the top cover connector, and the liquid injection hole is connected to the electrolyte inlet hole.

[0037] Furthermore, an explosion-proof valve is provided on the lower surface of the negative electrode top cover;

[0038] The notch of the explosion-proof valve occupies 7 / 8 of the full circle, and the other 1 / 8 has no notch.

[0039] In the above technical solution, the cylindrical lithium-ion battery structure provided by the present invention has the following beneficial effects:

[0040] The structure of the present invention is designed with a positive electrode connecting piece and a negative electrode connecting piece, and a positive electrode fuse connector and a negative electrode fuse connector are formed respectively. The fuse connector is used to adapt to the problem of core package movement, and a fuse design is realized, and it is ensured that the negative electrode fuse cross-sectional area is larger than the positive electrode fuse cross-sectional area, ensuring that the positive electrode is melted first, thereby improving space utilization and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0042] Figure 1 A schematic structural diagram of a cylindrical lithium-ion battery structure disclosed in an embodiment of the present application;

[0043] Figure 2 A structural cross-sectional view of a cylindrical lithium-ion battery structure disclosed in an embodiment of the present application;

[0044] Figure 3 An enlarged view of the connection structure of the positive terminal of a cylindrical lithium-ion battery structure disclosed in an embodiment of the present application;

[0045] Figure 4 An enlarged view of the connection structure of the negative terminal of a cylindrical lithium-ion battery structure disclosed in an embodiment of the present application;

[0046] Figure 5A schematic structural diagram of a positive electrode connecting piece of a cylindrical lithium-ion battery structure disclosed in an embodiment of the present application;

[0047] Figure 6 A schematic diagram of the structure of a negative electrode connecting piece of a cylindrical lithium-ion battery structure disclosed in an embodiment of the present application;

[0048] Figure 7 A schematic structural diagram of the front side of a negative electrode top cover of a cylindrical lithium-ion battery structure disclosed in an embodiment of the present application;

[0049] Figure 8 This is a schematic structural diagram of the bottom surface of a negative electrode top cover of a cylindrical lithium-ion battery structure disclosed in an embodiment of the present application.

[0050] Description of reference numerals:

[0051] 1. Positive pole; 2. Plastic on positive pole; 3. Shell; 4. Sealing ring; 5. Plastic on positive pole; 6. Positive connecting piece; 7. Core packing; 8. Negative connecting piece; 9. Negative top cover; 10. Integrated sealing nail;

[0052] 101. Inner hole of positive electrode column;

[0053] 601, positive electrode fuse connector; 602, positive electrode busbar; 603, current collecting column; 604, first hollow portion;

[0054] 801, negative electrode fuse connector; 802, negative electrode connector; 803, negative electrode collector; 804, electrolyte inlet hole; 805, second hollow portion;

[0055] 901, top cover connector; 902, liquid injection hole; 903, explosion-proof valve. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0057] See also Figures 1 to 8 As shown;

[0058] This embodiment discloses a cylindrical lithium-ion battery structure, which includes:

[0059] The shell 3 has a core package 7 embedded therein, and the core package 7 is a cylindrical core package;

[0060] A positive electrode connecting piece 6 and a negative electrode connecting piece 8 are located inside the housing 3 and are respectively arranged at the positive end and the negative end of the core package 7;

[0061] The positive electrode connecting piece 6 is provided with a plurality of positive electrode fusible connectors 601, and the positive electrode fusible connectors 601 provide resilience for the movement of the core package 7 through elastic deformation;

[0062] The negative electrode connecting piece 8 is provided with a plurality of negative electrode fusible connectors 801, and the negative electrode fusible connectors 801 provide resilience for the movement of the core package 7 through elastic deformation;

[0063] Both the positive electrode fusible link 601 and the negative electrode fusible link 801 can be fused at high temperature when the core package 7 is in an accident state.

[0064] In order to ensure that the positive electrode can be blown first, the cross-sectional area of ​​the negative electrode blown connector 801 of this embodiment is larger than the cross-sectional area of ​​the positive electrode blown connector 601. Preferably, the cross-sectional area of ​​the positive electrode blown in this embodiment is 14 to 50 square millimeters, and the cross-sectional area of ​​the negative electrode blown is 30 to 50 square millimeters; after reaching the melting point of copper and aluminum, it can be blown; the cross-sectional area of ​​the positive electrode blown is ≈ 1.5 times the cross-sectional area of ​​the negative electrode blown.

[0065] Specifically, this embodiment discloses a cylindrical lithium-ion battery structure, in which a positive electrode connecting piece 6 is provided at the positive electrode of the core package 7, and a negative electrode connecting piece 8 is provided at the negative electrode of the core package 7; wherein, the positive electrode connecting piece 6 of this embodiment has a positive electrode fuse connector 601, and the negative electrode connecting piece 8 has a negative electrode fuse connector 801, firstly, the elastic deformation of the positive electrode fuse connector 601 and the negative electrode fuse connector 801 is used to adapt to the movement problem of the core package 7 during use, and provide resilience; and the fuse connector will be melted at high temperature in an accident state, so that the connector has a fuse function. Not only the space utilization rate of the cylindrical lithium battery is improved, but also the safety is improved.

[0066] Preferably, the positive electrode of the core package 7 of this embodiment includes a positive electrode column 1, the lower part of the positive electrode column 1 is embedded in the shell 3; a positive electrode upper plastic 2 is arranged between the upper part of the positive electrode column 1 and the upper end of the shell 3, and the positive electrode upper plastic 2 is sleeved on the outside of the positive electrode column 1; a positive electrode lower plastic 5 matched with the part of the positive electrode column 1 embedded in the shell 3; and a positive electrode connecting piece 6;

[0067] In this embodiment, a sealing ring 4 is disposed between the positive electrode lower plastic 5 and the positive electrode column 1 .

[0068] Preferably, the positive electrode connecting piece 6 of this embodiment includes a positive electrode busbar 602; and a current collecting column 603 located at the center of the positive electrode busbar 602 and protruding toward the positive electrode column 1;

[0069] A plurality of positive electrode fusible connectors 601 are evenly distributed along the circumference of the positive electrode busbar 602, and one end of the positive electrode fusible connector 601 is connected to the current collecting column 603, and the other end extends along the radial direction of the positive electrode busbar 602;

[0070] A first hollow portion 604 is formed between the positive electrode fusible link 601 and the positive electrode busbar 602 .

[0071] The lower end of the positive electrode column 1 of this embodiment is recessed inward to form a positive electrode column inner hole 101 ; the current collecting column 603 is embedded in the positive electrode column inner hole 101 .

[0072] First, the present embodiment further defines the connection structure at one end of the positive electrode of the lithium battery, which includes a positive electrode column 1, a positive electrode upper plastic 2, a positive electrode lower plastic 5, a sealing ring 4 and a positive electrode connecting piece 6; wherein, the positive electrode connecting piece 6 of the present embodiment is formed with three positive electrode fuse connectors 601, corresponding to three first hollow portions 604, and is also formed with a positive electrode busbar 602 and a current collecting column 603; wherein, the positive electrode fuse connector 601 has a certain upward and downward rebound ability, and at the same time has a high-temperature fuse function, the positive electrode busbar 602 plays the function of gathering the positive electrode current of the battery cell, and the current collecting column 603 is connected to the positive electrode column 1 to achieve the purpose of outputting current.

[0073] When assembling the positive terminal of the lithium battery, the positive electrode column 1 is assembled with the positive electrode upper plastic 2 and then inserted into the hole of the shell 3. The sealing ring 4 cooperates with the outer edge of the positive electrode column 1 and is inserted into the positive electrode lower plastic 5. Finally, the positive electrode column 1 is turned over and riveted to assemble into the positive terminal of the lithium battery.

[0074] Preferably, a negative electrode connecting piece 8 and a negative electrode top cover 9 are provided at one negative electrode end of the core package 7 of this embodiment;

[0075] An integrated sealing nail 10 is installed at the center of the negative electrode top cover 9 , the negative electrode connecting sheet 8 and one end of the negative electrode of the core package 7 .

[0076] The negative electrode connecting sheet 8 of this embodiment includes a negative electrode connecting body 8; and a negative electrode collector 803 formed in the inner area of ​​the negative electrode connecting body 8, and an electrolyte inlet hole 804 is opened in the center of the negative electrode collector 803;

[0077] The negative electrode current collector 803 and the negative electrode connector 802 are connected by a plurality of negative electrode fuse connectors 801 uniformly distributed along the circumference of the negative electrode connector 802;

[0078] The side surface of the negative electrode fusible link 801 is a second hollow portion 805 .

[0079] As a preference, one end of the negative electrode fuse connector 801 of this embodiment is connected to the negative electrode current collector 803, and the other end is connected to the negative electrode connector 802, and the negative electrode top cover 9 of this embodiment includes a top cover connector 901, which is connected to the negative electrode connector 802; and a liquid injection hole 902 formed at the center of the top cover connector 901, and the liquid injection hole 902 is connected to the electrolyte inlet hole 804.

[0080] This embodiment further defines the connection structure of the negative terminal. Based on the connection structure of the positive terminal, when the battery cell is assembled, the positive connecting piece 6 is assembled with the core package 7, and the positive current collector 602 is connected to the positive pole ear end of the core package 7. Secondly, the negative connecting piece 8 of this embodiment is assembled with the core package 7, and the negative current collector 803 is connected to the negative pole ear of the core package 7. After the positive and negative connecting pieces are assembled with the core package 7, they are placed in the shell 3 as a whole, with the positive electrode facing upward. Assemble the negative top cover 9 with the shell 3, and finally assemble the integrated sealing nail 10 with the negative top cover 9. The current collector 603 is connected to the inner hole 10 of the positive pole column, and the negative connector 8 is connected to the top cover connector 901 of the negative top cover 9.

[0081] Finally, in order to enable the battery cell to have directional pressure relief capability, an explosion-proof valve 903 is provided on the lower surface of the negative electrode top cover 9 of this embodiment; the notch of the explosion-proof valve 903 occupies 7 / 8 of the entire circle, and the other 1 / 8 is not notched. The explosion-proof valve 903 of this embodiment can open the valve in a fixed point and direction, ensuring the safety of the battery cell under extreme conditions.

[0082] The battery assembly of this embodiment is simple. The positive and negative electrode connecting plates are first welded together with the positive and negative electrodes of the core package 7. The core package 7 with the positive and negative electrode connecting plates welded is placed in the shell 3, and the negative electrode top cover 9 is assembled with the shell 3. After welding, the assembly is completed; the battery structure has a high space utilization rate. The negative electrode top cover 9 is directly welded to the shell 3, which eliminates the curling and rolling process and improves the space utilization rate of the battery cell.

[0083] In the above technical solution, the cylindrical lithium-ion battery structure provided by the present invention has the following beneficial effects:

[0084] The structure of the present invention is designed with a positive electrode connecting piece 6 and a negative electrode connecting piece 8, and respectively forms a positive electrode fuse connector 601 and a negative electrode fuse connector 801, utilizes the fuse connector to adapt to the problem of the core package 7 moving, realizes the fuse design, and ensures that the negative electrode fuse cross-sectional area is larger than the positive electrode fuse cross-sectional area, ensures that the positive electrode fuses first, improves space utilization, and can also improve safety.

[0085] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A cylindrical lithium-ion battery structure, characterized in that: The structure includes: A shell (3), wherein a core package (7) is embedded in the shell (3), and the core package (7) is a cylindrical core package; A positive electrode connecting piece (6) and a negative electrode connecting piece (8) located inside the shell (3) and respectively arranged at the positive terminal and negative terminal of the core package (7); The positive electrode connecting piece (6) is provided with a plurality of positive electrode fusible connectors (601), and the positive electrode fusible connectors (601) provide resilience for the movement of the core package (7) through elastic deformation; The negative electrode connecting piece (8) is provided with a plurality of negative electrode fusible connectors (801), and the negative electrode fusible connectors (801) provide resilience for the movement of the core package (7) through elastic deformation; The positive electrode fusible connector (601) and the negative electrode fusible connector (801) can both be fused at high temperature when the core package (7) is in an accident state.

2. A cylindrical lithium-ion battery structure according to claim 1, characterized in that: The cross-sectional area of ​​the negative electrode fusible connector (801) is greater than the cross-sectional area of ​​the positive electrode fusible connector (601).

3. A cylindrical lithium-ion battery structure according to claim 1 or 2, characterized in that: The positive electrode of the core package (7) comprises: A positive electrode column (1), the lower part of which is embedded in the shell (3); A positive electrode upper plastic (2) disposed between the upper portion of the positive electrode column (1) and the upper end of the shell (3), wherein the positive electrode upper plastic (2) is sleeved on the outside of the positive electrode column (1); A positive electrode lower plastic (5) that cooperates with the portion of the positive electrode column (1) embedded in the shell (3); and The positive electrode connecting piece (6); A sealing ring (4) is provided between the positive electrode lower plastic (5) and the positive electrode column (1).

4. A cylindrical lithium-ion battery structure according to claim 3, characterized in that: The positive electrode connecting sheet (6) comprises: A positive busbar (602); and A current collecting column (603) located at the center of the positive electrode current collecting plate (602) and protruding toward the positive electrode column (1); The plurality of positive electrode fusible connectors (601) are evenly distributed along the circumference of the positive electrode busbar (602), and one end of the positive electrode fusible connector (601) is connected to the current collecting column (603), and the other end extends along the radial direction of the positive electrode busbar (602); A first hollow portion (604) is formed between the positive electrode fusible connector (601) and the positive electrode busbar (602).

5. A cylindrical lithium-ion battery structure according to claim 4, characterized in that: The lower end of the positive electrode column (1) is recessed inward to form a positive electrode column inner hole (101); The current collecting column (603) is embedded in the inner hole (101) of the positive electrode column.

6. A cylindrical lithium-ion battery structure according to claim 1 or 2, characterized in that: The negative electrode end of the core package (7) is provided with the negative electrode connecting piece (8) and the negative electrode top cover (9); An integrated sealing nail (10) is installed at the center of the negative electrode top cover (9), the negative electrode connecting sheet (8) and one end of the negative electrode of the core package (7).

7. A cylindrical lithium-ion battery structure according to claim 6, characterized in that: The negative electrode connecting piece (8) comprises: A negative electrode connector (802); and A negative electrode collector (803) is formed in the inner area of ​​the negative electrode connector (802), and an electrolyte inlet hole (804) is opened at the center of the negative electrode collector (803); The negative electrode collector (803) and the negative electrode connector (802) are connected via a plurality of negative electrode fuse connectors (801) uniformly distributed along the circumference of the negative electrode connector (802); The side surface of the negative electrode fusible connector (801) is a second hollow portion (805).

8. A cylindrical lithium-ion battery structure according to claim 7, characterized in that: One end of the negative electrode fuse connector (801) is connected to the negative electrode current collector (803), and the other end is connected to the negative electrode connector (802), and the negative electrode fuse connector (801) is arranged in an inclined structure.

9. A cylindrical lithium-ion battery structure according to claim 7, characterized in that: The negative electrode top cover (9) comprises: A top cover connector (901), the top cover connector (901) being connected to the negative electrode connector (802); and A liquid injection hole (902) is formed at the center of the top cover connector (901), and the liquid injection hole (902) is connected to the electrolyte inlet hole (804).

10. A cylindrical lithium-ion battery structure according to claim 9, characterized in that: An explosion-proof valve (903) is provided on the lower surface of the negative electrode top cover (9); The notch of the explosion-proof valve (903) occupies 7 / 8 of the entire circle, and the other 1 / 8 has no notch.

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