Lithium battery and battery pack

Abstract

The present invention provides a lithium battery and a battery pack, comprising a reference electrode and a seal, wherein the reference electrode is divided into a first electrode segment to an Nth electrode segment along the length direction, and a connecting segment located between two adjacent electrode segments; the diaphragm includes a first diaphragm and a second diaphragm, the reference electrode is arranged between the negative electrode and the first diaphragm, or between the positive electrode and the first diaphragm, and the surface of the reference electrode is wrapped by the second diaphragm; the seals are sequentially provided with N pieces from the inside to the outside, and the seal in the nth order and the seal in the n-1th order independently isolate the nth electrode segment of the reference electrode, and the seal in the nth order and the seal in the n-1th order are both provided with a through hole for moving the reference electrode. By controlling the different electrode segments of the reference electrode to contact the electrolyte at set times, the service life of the reference electrode is extended, and the accuracy of the test results is guaranteed.

Description

Technical Field

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

[0002] With the development of new energy technologies, lithium batteries, with their high energy density and long service life, have found widespread application. Lithium batteries are composed of materials such as a positive electrode, a negative electrode, a separator, and an electrolyte, but they themselves are relatively complex systems. A key metric for measuring lithium batteries is their cycle life, which is influenced by parameters such as the battery's operating temperature, charge current, discharge current, and cutoff voltage. During the cycling of a battery cell, the electrode potential changes. Precisely measuring the electrode potential changes at different stages of the cycle is crucial for accurately studying the cycle life of the battery cell.

[0003] Currently, the common approach to studying the electrode potential of lithium-ion batteries is to place a reference electrode inside the battery and monitor the potential changes of the corresponding electrode. However, since the reference electrode must be placed inside the battery cell before sealing, prolonged contact between the reference electrode and the electrolyte can easily cause corrosion on the reference electrode surface, perturbing the potential of the reference electrode during measurement and preventing accurate measurement of the corresponding potential changes. Two common approaches are available. One approach involves coating the reference electrode with a polymeric material, which can somewhat slow down electrolyte corrosion. However, this process is complex, and corrosion can persist even after prolonged storage. Another approach involves disassembling the cell after a period of cycling, relocating the reference electrode, and then repackaging the cell containing the reference electrode. Disassembled cells are susceptible to side reactions with moisture and oxygen in the air, which can affect their performance. Furthermore, the failure rate of reassembling disassembled cells is high, affecting the accuracy of test results.

[0004] Based on the above reasons, extending the service life of the reference electrode and ensuring the accuracy of the test results are particularly important in studying the changes in electrode potential. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to extend the service life of the reference electrode and ensure the accuracy of the test results.

[0006] The present invention provides a lithium battery, comprising a positive electrode, a negative electrode, a diaphragm, an electrolyte, a reference electrode and a seal, wherein the positive electrode and the negative electrode are stacked and alternately arranged in sequence, the diaphragm is arranged between the positive electrode and the negative electrode, and the reference electrode is divided into a first electrode segment to an Nth electrode segment along the length direction, and a connecting segment located between two adjacent electrode segments; the diaphragm includes a first diaphragm and a second diaphragm, the reference electrode is arranged between the negative electrode and the first diaphragm, or between the positive electrode and the first diaphragm, and the surface of the reference electrode is covered by the second diaphragm. The seal is wrapped with a diaphragm; N seals are arranged in sequence from the inside to the outside, and in order from the inside to the outside, the positive electrode, the negative electrode, the first electrode segment of the reference electrode, the diaphragm and the electrolyte are arranged in the seal arranged in the first order, the seal arranged in the nth order and the seal arranged in the n-1th order independently isolate the nth electrode segment of the reference electrode, and the seal arranged in the nth order and the seal arranged in the n-1th order are both provided with a through hole for the reference electrode to move through, N is an integer greater than or equal to 2, and n is an integer greater than or equal to 2 and less than or equal to N.

[0007] Optionally, the positive electrode includes a positive electrode tab and a positive electrode sheet, the positive electrode tab extends from one side of the positive electrode sheet along the plane where the positive electrode sheet is located; the positive electrode tab has a first opening suitable for the movement of the reference electrode; the negative electrode includes a negative electrode tab and a negative electrode sheet, the negative electrode tab extends from one side of the negative electrode sheet along the plane where the negative electrode sheet is located; the negative electrode tab has a second opening suitable for the movement of the reference electrode; the area of the negative electrode sheet is larger than the area of the positive electrode sheet; the reference electrode is respectively provided with the first opening and the second opening.

[0008] Optionally, the first opening of the positive electrode tab is away from the center of the positive electrode tab, and the second opening of the negative electrode tab is away from the center of the negative electrode tab.

[0009] Optionally, the area of the negative electrode plate is less than or equal to 1.5 times the area of the positive electrode plate.

[0010] Optionally, any nth electrode segment and the (n+1)th electrode segment of the reference electrode are connected to form a U shape via a connecting segment therebetween; any adjacent U-shaped openings are opposite.

[0011] Optionally, the length of the nth electrode segment of the reference electrode is greater than or equal to the length of the first electrode segment of the reference electrode.

[0012] Optionally, the diameter of the reference electrode is smaller than the width of the first opening of the positive electrode tab; the diameter of the reference electrode is smaller than the width of the second opening of the negative electrode tab.

[0013] Optionally, the nth electrode segment of any reference electrode is arranged on a side of the positive electrode tab away from the negative electrode tab, and / or the nth electrode segment of any reference electrode is arranged on a side of the negative electrode tab away from the positive electrode tab.

[0014] Optionally, the through hole is at least one of a circular hole, a square hole, a triangular hole, and a regular hexagonal hole.

[0015] The present invention also provides a battery pack comprising the above-mentioned lithium battery.

[0016] The above technical solution of the present invention has the following beneficial effects:

[0017] The lithium battery provided by the technical solution of the present invention independently isolates the nth electrode segment of the reference electrode through the seal arranged in the nth position and the seal arranged in the n-1th position, so as to prevent the nth electrode segment of the reference electrode from contacting with the electrolyte and becoming ineffective when not in use. When it is necessary to perform the first potential study on the electrode of the lithium battery, the Nth seal is unsealed, the first electrode segment of the reference electrode is pulled out from the first seal, and the second electrode segment of the reference electrode enters the first seal, so that the second electrode segment of the reference electrode contacts with the electrolyte and conducts electricity; and similarly, when it is necessary to perform the second potential study on the electrode of the lithium battery, the N-1th seal is unsealed, the second electrode segment of the reference electrode is pulled out from the first seal, and the third electrode segment of the reference electrode enters the first seal, so that the third electrode segment of the reference electrode contacts with the electrolyte and conducts electricity... By controlling the different electrode segments of the reference electrode to contact the electrolyte at set times, it is ensured that each time the electrode potential of the lithium battery is studied, the reference electrode used is a different electrode segment of an unused reference electrode, thereby extending the service life of the reference electrode and ensuring the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a schematic diagram of a reference electrode in a lithium battery according to an embodiment of the present application;

[0020] Figure 2 Schematic diagram of the positive electrode sheet and the negative electrode sheet of the embodiment of the present application;

[0021] Figure 3 This is a schematic diagram of the arrangement of the reference electrode in the lithium battery according to an embodiment of the present application;

[0022] Figure 4 This is a schematic diagram of a reference electrode in a lithium battery according to an embodiment of the present application;

[0023] Figure 5 This is a schematic diagram of a reference electrode in a lithium battery according to another embodiment of the present application;

[0024] Figure 6 This is a schematic diagram of the aluminum-plastic film after punching holes in an embodiment of the present application.

[0025] Reference numerals:

[0026] 1. Negative electrode tab; 2. Positive electrode tab; 3. Reference electrode; 4. Negative electrode; 5. Positive electrode; 6. Diaphragm; 8. First seal; 9. Second seal; 10. Third seal. DETAILED DESCRIPTION

[0027] The technical solutions of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Example 1

[0029] An embodiment of the present invention provides a lithium battery, such as Figure 1 and Figure 4As shown, it includes a positive electrode 5, a negative electrode 4, a diaphragm 6, a reference electrode 3 and a seal, wherein the positive electrode 5, the negative electrode 4 and the diaphragm 6 are immersed in an electrolyte (not shown in the figure), the positive electrode 5 and the negative electrode 4 are stacked and arranged alternately in sequence, and the diaphragm 6 is arranged between the positive electrode 5 and the negative electrode 4; the reference electrode 3 is divided into a first electrode segment to an Nth electrode segment along the length direction, and a connecting segment located between two adjacent electrode segments; the diaphragm 6 includes a first diaphragm and a second diaphragm, and the reference electrode 3 is arranged between the negative electrode 4 and the first diaphragm, or between the positive electrode 5 and the first diaphragm, The surface of the reference electrode 3 is wrapped by the second diaphragm; the seals are provided in N order from the inside to the outside, and in order from the inside to the outside, the positive electrode 5, the negative electrode 4, the first electrode segment of the reference electrode 3, the diaphragm 6 and the electrolyte are arranged in the seal in the first order, and the seal in the nth order and the seal in the n-1th order independently isolate the nth electrode segment of the reference electrode 3, and the seal in the nth order and the seal in the n-1th order are both provided with a through hole for the reference electrode to move through; N is an integer greater than or equal to 2, and n is an integer greater than or equal to 2 and less than or equal to N. The lithium battery is stacked in a repeated alternating manner of positive electrode 5, diaphragm 6, negative electrode 4, and diaphragm 6. The reference electrode 3 runs across the interior of the lithium battery along the Y-axis direction. The surface of the reference electrode 3 is wrapped by a second diaphragm. The second diaphragm allows lithium ions to penetrate freely without affecting the lithium plating on the surface of the reference electrode 3, and prevents the reference electrode 3 from damaging the electrode during the subsequent movement process, avoiding direct contact with the positive electrode 5 or the negative electrode 4 inside the lithium battery to cause a short circuit.

[0030] In this embodiment, the value of N can be reasonably limited according to the needs of actual application.

[0031] In this embodiment, the nth electrode segment of the reference electrode 3 is independently isolated by the seal arranged in the nth position and the seal arranged in the n-1th position, so as to prevent the nth electrode segment of the reference electrode 3 from contacting with the electrolyte and becoming ineffective when not in use. When it is necessary to perform the first potential study on the electrode of the lithium battery, the Nth seal is unsealed, the first electrode segment of the reference electrode 3 is pulled out from the first seal, and the second electrode segment of the reference electrode 3 enters the first seal 8, so that the second electrode segment of the reference electrode 3 contacts the electrolyte and conducts electricity; and similarly, when it is necessary to perform the second potential study on the electrode of the lithium battery, the N-1th seal is unsealed, the second electrode segment of the reference electrode 3 is pulled out from the first seal 8, and the third electrode segment of the reference electrode 3 enters the first seal 8, so that the third electrode segment of the reference electrode 3 contacts the electrolyte and conducts electricity…. By controlling the different electrode segments of the reference electrode 3 to contact the electrolyte at set times, it is ensured that each time the electrode potential of the lithium battery is studied, the reference electrode 3 used is a different electrode segment of the unused reference electrode 3, thereby extending the service life of the reference electrode 3 and ensuring the accuracy of the test results.

[0032] In this embodiment, the positive electrode 5 includes a positive electrode tab 2 and a positive electrode sheet, and the positive electrode tab 2 extends from one side of the positive electrode sheet along the plane where the positive electrode sheet is located; the positive electrode tab 2 has a first opening suitable for the movement of the reference electrode 3; the negative electrode includes a negative electrode tab 1 and a negative electrode sheet, and the negative electrode tab 1 extends from one side of the negative electrode sheet along the plane where the negative electrode sheet is located; the negative electrode tab 1 has a second opening suitable for the movement of the reference electrode 3; the area of the negative electrode sheet is larger than the area of the positive electrode sheet, and the reference electrode 3 passes through the first opening and the second opening respectively, so that each electrode segment of the reference electrode 3 can be pulled in and out.

[0033] In this embodiment, the reference electrode 3 moves through the first opening of the positive electrode tab 2 and the second opening of the negative electrode tab 1 to avoid leading out the reference electrode 3 at other positions of the seal, thereby reducing the number of openings on the seal to improve the sealing performance of the seal; in the design of lithium batteries, it is necessary to ensure that the area of the negative electrode sheet is larger than the area of the positive electrode sheet. If the area of the positive electrode sheet is larger than the area of the negative electrode sheet, there will be a risk of lithium plating on the surface of the negative electrode 4 during charging, affecting the safety of the lithium battery.

[0034] In this embodiment, the area of the negative electrode plate is less than 1.5 times the area of the positive electrode plate. If the area of the negative electrode plate is greater than 1.5 times the area of the positive electrode plate, it will cause great waste and increase costs.

[0035] In this embodiment, the first opening of the positive electrode tab 2 is away from the center of the positive electrode tab 2, and the second opening of the negative electrode tab 1 is away from the center of the negative electrode tab 1. With this arrangement, after the lithium battery is packaged, the first opening and the second opening are located away from the electrolyte, reducing the risk of electrolyte overflowing from the first opening or the second opening. Specifically, Figure 2 As shown, L0 is the width of the first opening and the second opening, L1 and L2 are the distances from the second opening to both sides of the negative electrode tab, L3 and L4 are the distances from the first opening to both sides of the positive electrode tab, L1<L2, L3<L4.

[0036] In this embodiment, the width of the first opening of the positive electrode tab 2 is less than 2 mm, and the width of the second opening of the negative electrode tab 1 is less than 2 mm. This ensures that the reference electrode 3 can move through the first opening of the positive electrode tab 2 and the second opening of the negative electrode tab 1, while reducing the risk of electrolyte overflowing from the first opening or the second opening.

[0037] In this embodiment, any nth electrode segment and the n+1th electrode segment of the reference electrode 3 are connected to form a U-shape via a connecting segment therebetween; any adjacent U-shaped openings are opposite. The U-shaped arrangement of the connecting segments effectively reduces the space occupied by the connecting segments, thereby reducing the volume of the lithium battery.

[0038] Specifically, such as Figure 3 As shown, the reference electrode 3 is placed on the negative electrode sheet or the positive electrode sheet; the reference electrode is led out from point a, along the Y-axis direction, to point b, along the X-axis direction, to point c, and then along the Y-axis direction, to point d. The length of the reference electrode 3 at cd is greater than 10 mm; along the X-axis direction, it reaches point e, along the Y-axis direction, to point f, and the length of the reference electrode 3 at ef is greater than 10 mm; along the X-axis direction, it reaches point g, and then along the Y-axis direction, it reaches point h. Point h is located at the first opening or the second opening. The reference electrode 3 arranged at point gh has no obvious bend. The reference electrode 3 reaches point i along the X-axis direction, along the Y-axis direction, to point j, and the length of the reference electrode 3 at ij is greater than 10 mm; the reference electrode 3 reaches point k along the X-axis direction, along the Y-axis direction, to point l, and the length of the reference electrode 3 at kl is greater than 10 mm; along the X-axis direction, it reaches point m, and along the Y-axis direction, it reaches point n. And so on, the arrangement of the reference electrode 3 is completed.

[0039] In this embodiment, the length of the nth electrode segment of the reference electrode 3 is greater than or equal to the length of the first electrode segment of the reference electrode 3. This ensures that each time the electrode potential of the lithium battery is studied, the reference electrode 3 used is a different electrode segment of the unused reference electrode 3.

[0040] In this embodiment, the diameter of the reference electrode 3 is smaller than the width of the first opening of the positive electrode tab 2; the diameter of the reference electrode is smaller than the width of the second opening of the negative electrode tab 1. This ensures that the reference electrode 3 can move through the first opening of the positive electrode tab 2 and the second opening of the negative electrode tab 1.

[0041] In this embodiment, the nth electrode segment of any reference electrode is arranged on the side of the positive electrode tab 2 away from the negative electrode tab 1, or the nth electrode segment of any reference electrode is arranged on the side of the negative electrode tab 1 away from the positive electrode tab 2. Such an arrangement is beneficial for the reference electrode to be withdrawn in one direction only from the positive electrode tab side or the negative electrode tab side, thereby ensuring that the electrode segments of the unused reference electrode are independently isolated between two adjacent seals.

[0042] In one embodiment, if Figure 4 As shown, the nth electrode segment of any reference electrode is arranged on the side of the positive electrode tab 2 away from the negative electrode tab 1. When the first potential study of the lithium battery electrode is required, the Nth seal is unsealed, the first electrode segment of the reference electrode 3 is pulled out from the side of the negative electrode tab 1, and the second electrode segment of the reference electrode 3 enters the first seal from the side of the positive electrode tab 2, so that the second electrode segment of the reference electrode 3 contacts the electrolyte and conducts electricity; and so on, when the second potential study of the lithium battery electrode is required, the N-1th seal is unsealed, the second electrode segment of the reference electrode 3 is pulled out from the side of the negative electrode tab 1, and the third electrode segment of the reference electrode 3 enters the first seal from the side of the positive electrode tab 2, so that the third electrode segment of the reference electrode 3 contacts the electrolyte and conducts electricity….

[0043] In another embodiment, Figure 5 As shown, the nth electrode segment of any reference electrode is arranged on the side of the negative electrode tab 1 away from the positive electrode tab 2. When the first potential study of the lithium battery electrode is required, the Nth seal is unsealed, the first electrode segment of the reference electrode 3 is pulled out from the side of the positive electrode tab 2, and the second electrode segment of the reference electrode enters the first seal from the side of the negative electrode tab 1, so that the second electrode segment of the reference electrode 3 is in contact with the electrolyte and conducts electricity; and so on, when the second potential study of the lithium battery electrode is required, the N-1th seal is unsealed, the second electrode segment of the reference electrode 3 is pulled out from the side of the positive electrode tab 2, and the third electrode segment of the reference electrode 3 enters the first seal from the side of the negative electrode tab 1, so that the third electrode segment of the reference electrode 3 is in contact with the electrolyte and conducts electricity….

[0044] In this embodiment, the through hole can be a single circular hole, square hole, triangular hole, regular hexagonal hole or other geometric shape hole, or it can be any combination of multiple hole rows. Circular holes are preferred because circular holes are suitable for sealing. The reference electrode moves through the circular hole, and the circular hole structure causes less wear on the surface of the reference electrode, thereby protecting the integrity of different electrode segments of the reference electrode.

[0045] In one embodiment, if Figure 5 As shown, a lithium battery having a first electrode segment of a reference electrode 3 is placed, and the positive electrode tab 2 and the negative electrode tab 1 are welded, and the battery is placed in a first seal 8. The first seal 8 has a circular hole suitable for the movement of the reference electrode 3, through which the reference electrode 3 can be pulled back and forth. The second electrode segment of the reference electrode 3 reserved outside the first seal 8 is arranged, and the arranged second electrode segment of the reference electrode 3 is placed in a second seal 9. The second seal 9 has a circular hole suitable for the movement of the reference electrode 3, through which the reference electrode 3 can be pulled back and forth. The third electrode segment of the reference electrode 3 reserved outside the second seal is arranged, and the arranged third electrode segment of the reference electrode 3 is placed in a third seal 10. The third seal 10 has a circular hole suitable for the movement of the reference electrode 3, through which the reference electrode 3 can be pulled back and forth. After the reference electrode 3 is arranged inside the three seals, the circular hole of the third seal 10 is sealed with sealant to ensure the airtightness of the battery cell. The prepared lithium battery was subjected to a cycle test using a charging method of 2C CC / 1C DC. After every 200 cycles, the reference electrode was plated with lithium, and the potential change of the reference electrode was tested. The test results are shown in Table 1, where Group A is the lithium battery of this embodiment and Group B is a conventional lithium battery. Before the Group A lithium battery was tested, the outermost seal was disassembled and the reference electrode remaining inside the lithium battery was pulled out to ensure that the reference electrode was a fresh interface during each measurement and was not in contact with the electrolyte. After the above steps were completed, the reference electrode was plated with lithium, and the potential change of the reference electrode was tested. The Group B lithium battery did not need to be disassembled, and the reference electrode was directly plated with lithium, and the reference electrode potential was tested. It can be seen that compared to the Group A lithium battery, as the number of cycles of the Group B lithium battery increased, the reference electrode was in contact with the electrolyte for a long time, causing the reference electrode surface to be corroded, the electrode fluctuation was obvious, and it was impossible to accurately feedback the corresponding terminal potential.

[0046] Table 1

[0047]

[0048] In this embodiment, the material of the sealing member is aluminum-plastic film. The aluminum-plastic film is suitable for packaging of various shapes; the packaged aluminum-plastic film has the functions of hygiene, cleanliness, sealing packaging, and dust and moisture resistance. Figure 6 As shown, the aluminum-plastic film is punched, and after each punching, the punching area gradually increases, and finally a seal with different specifications is formed.

[0049] Example 2

[0050] This embodiment provides a battery pack including the lithium battery of embodiment 1. By in-situ monitoring the positive electrode potential, negative electrode potential, and impedance of the lithium battery during use, the detection accuracy is significantly improved, the detection efficiency is high, and it is conducive to promoting the research of battery pack life.

[0051] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A lithium battery comprising a positive electrode, a negative electrode, a separator and an electrolyte, wherein the positive electrode and the negative electrode are alternately stacked in sequence, and the separator is disposed between the positive electrode and the negative electrode, characterized in that: Also included are the reference electrode and seal; The reference electrode is divided into a first electrode segment to an Nth electrode segment along the length direction, and a connecting segment located between two adjacent electrode segments; the diaphragm includes a first diaphragm and a second diaphragm, the reference electrode is arranged between the negative electrode and the first diaphragm, or between the positive electrode and the first diaphragm, and the surface of the reference electrode is wrapped by the second diaphragm; The sealing members are provided with N pieces in sequence from the inside to the outside. Counted from the inside to the outside, the first electrode segment of the positive electrode, the negative electrode, and the reference electrode, the diaphragm, and the electrolyte are provided in the sealing member in the first order. The sealing member in the nth order and the sealing member in the n-1th order independently isolate the nth electrode segment of the reference electrode from contact with the electrolyte. Both the sealing member in the nth order and the sealing member in the n-1th order are provided with a through hole for the reference electrode to move through. N is an integer greater than or equal to 3, and n is an integer greater than or equal to 2 and less than or equal to N. The through holes of each sealing member include an outlet through hole and an inlet through hole located on opposite sides of the lithium battery, and the reference electrode passes through the outlet through hole and the inlet through hole; the outlet through hole is suitable for withdrawing the reference electrode, and the inlet through hole is suitable for entering the reference electrode; The length of the nth electrode segment of the reference electrode is greater than or equal to the length of the first electrode segment of the reference electrode.

2. The lithium battery according to claim 1, characterized in that The positive electrode includes a positive electrode tab and a positive electrode sheet, wherein the positive electrode tab extends from one side of the positive electrode sheet along the plane where the positive electrode sheet is located; the positive electrode tab has a first opening suitable for moving a reference electrode; The negative electrode includes a negative electrode tab and a negative electrode plate, wherein the negative electrode tab extends from one side of the negative electrode plate along the plane where the negative electrode plate is located; the negative electrode tab has a second opening suitable for moving a reference electrode, and the area of the negative electrode plate is larger than that of the positive electrode plate; The reference electrode is respectively provided through the first opening and the second opening.

3. The lithium battery according to claim 2, characterized in that The first opening of the positive electrode tab is away from the center of the positive electrode tab, and the second opening of the negative electrode tab is away from the center of the negative electrode tab.

4. The lithium battery according to claim 2, characterized in that The area of the negative electrode plate is less than or equal to 1.5 times the area of the positive electrode plate.

5. The lithium battery according to any one of claims 2 to 4, characterized in that: Any n-th electrode segment and the (n+1)-th electrode segment of the reference electrode are connected to form a U shape via a connecting segment therebetween; any adjacent U-shaped openings are opposite.

6. The lithium battery according to claim 5, characterized in that The diameter of the reference electrode is smaller than the width of the first opening of the positive electrode tab; the diameter of the reference electrode is smaller than the width of the second opening of the negative electrode tab.

7. The lithium battery according to claim 1, characterized in that The nth electrode segment of any reference electrode is arranged on the side of the positive electrode tab away from the negative electrode tab, or the nth electrode segment of any reference electrode is arranged on the side of the negative electrode tab away from the positive electrode tab.

8. The lithium battery according to claim 1, wherein The through hole is at least one of a circular hole, a square hole, a triangular hole, and a regular hexagonal hole.

9. A battery pack, characterized in that: A lithium battery comprising the lithium battery according to any one of claims 1 to 8.

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