Battery cell, battery, vehicle and battery cell lithium supplementing method

Abstract

The invention discloses a battery cell, a battery, a vehicle and a battery cell lithium supplementing method, and relates to the technical field of lithium batteries. The battery cell comprises a battery cell body, an end cover, a positive electrode, a negative electrode and a lithium-containing electrode, the end cover is arranged at one end of the battery cell body and is provided with a first pole, a second pole and a third pole; one end of each of the positive electrode, the negative electrode and the lithium-containing electrode is connected with the battery cell body, the other end of the positive electrode is connected with the first pole, the other end of the negative electrode is connected with the second pole, and the other end of the lithium-containing electrode is connected with the third pole. The lithium-containing electrode is arranged on the battery cell body, so that lithium is supplemented in time when the lithium ion content of the battery cell is insufficient, and the problems that the active lithium loss of the lithium battery cell used for a long time at present is relatively large, and the lithium ion capacity is insufficient are solved. Therefore, the battery cell provided by the embodiment of the invention has the advantages of prolonging the cycle life of the battery and improving the convenience of lithium supplement operation.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, a vehicle, and a method for replenishing lithium in a battery cell. Background Art

[0002] Currently, lithium-ion batteries are widely used as energy storage systems in electric vehicles due to their high energy density, excellent power characteristics, long cycle life, and environmental friendliness. However, as the vehicle is used in operation, the battery cells are prone to capacity decay, resulting in a reduction in the number of cycles. The loss of active lithium is one of the main reasons for the capacity decay of the battery cells. In related technologies, lithium replenishment is usually achieved by attaching lithium strips, lithium powder, etc. to the surface of the negative electrode sheet, so that the metallic lithium is in direct contact with the electrode material. This lithium replenishment method has problems with speed controllability and poor effect. Summary of the Invention

[0003] In view of this, the present application provides a battery cell and method that can improve the current problem of large active lithium loss and insufficient lithium ion capacity in lithium battery cells used for a long time.

[0004] In a first aspect, the present application provides a battery cell comprising a battery cell body, an end cap, a positive electrode, a negative electrode and a lithium-containing electrode.

[0005] The end cover is arranged at one end of the battery cell body, and the end cover is provided with a first pole, a second pole and a third pole; one end of each of the positive electrode, the negative electrode and the lithium-containing electrode is connected to the battery cell body, the other end of the positive electrode is connected to the first pole, the other end of the negative electrode is connected to the second pole, and the other end of the lithium-containing electrode is connected to the third pole.

[0006] Optionally, the lithium-containing electrode is a lithium ribbon or a metallic lithium foil.

[0007] Optionally, the lithium content of the lithium-containing electrode is 1 gram to 20 grams.

[0008] Optionally, the mass proportion of lithium element in the lithium-containing electrode ranges from 25% to 100%.

[0009] Optionally, the battery cell body includes a core, an electrolyte and a shell, the core and the electrolyte are both arranged inside the shell, and one end of the lithium-containing electrode is immersed in the electrolyte.

[0010] Optionally, the lithium-containing electrode is a supplementary electrode of the negative electrode, and the positive electrode, the lithium-containing electrode and the negative electrode are arranged on the battery cell body in sequence and spaced apart along the preset direction, and the distance between the positive electrode and the lithium-containing electrode is greater than the distance between the lithium-containing electrode and the negative electrode.

[0011] Optionally, the lithium-containing electrode includes an electrode body and a connecting piece connected to each other, and the connecting piece is connected to the third pole through a hot-melt layer.

[0012] Optionally, the lithium-containing electrode includes an electrode body and a connecting piece connected to each other, and the connecting piece is welded to the third pole.

[0013] Optionally, the connecting sheet is a metal copper foil or a carbon-coated copper foil, and the thickness of the connecting sheet is 4.5 microns to 20 microns.

[0014] In a second aspect, the present application provides a method for replenishing lithium in a battery cell, which is applied to the battery cell provided in the first aspect, and the method comprises:

[0015] The lithium ion capacity of the target battery cell is periodically collected through a monitoring system; when the lithium ion capacity is lower than a preset capacity threshold, the positive electrode of the external power supply is connected to the lithium-containing electrode, and the negative electrode of the external power supply is connected to the second pole, so that the lithium ions in the lithium-containing electrode are replenished to the negative electrode connected to the second pole; or, the negative electrode of the external power supply is connected to the lithium-containing electrode, and the positive electrode of the external power supply is connected to the first pole, so that the lithium ions in the lithium-containing electrode are replenished to the positive electrode connected to the first pole.

[0016] Optionally, the charging cut-off voltage range for the positive electrode is 3.55V to 3.65V, and the charging cut-off voltage range for the negative electrode is 0.01V to 0.03V.

[0017] Optionally, the lithium ion capacity of the battery cell is 100 Ah to 200 Ah, and the preset capacity threshold is 75% to 90% of the lithium ion capacity.

[0018] In a third aspect, the present application provides a lithium battery, which includes the battery cell as described in the first aspect.

[0019] In a fourth aspect, the present application provides a vehicle comprising the battery cell as mentioned in the first aspect or the lithium battery as mentioned in the third aspect.

[0020] By means of the above technical solution, the present application provides a battery cell, a battery, a vehicle, and a method for replenishing lithium in a battery cell. The battery cell of the embodiment of the present invention provides a lithium-containing electrode on the battery cell, and electrically connects the two ends of the lithium-containing electrode to the battery cell body and the end cap (third pole) respectively. During the use of the battery cell, if problems such as low capacitance are detected on the tab or the electrode sheet of the battery cell body, lithium replenishment can be performed through the lithium-containing electrode. This solves the problem of poor cycle performance caused by large loss of active lithium after multiple charge and discharge cycles. Furthermore, the cycle life of the battery cell is improved.

[0021] Furthermore, the third terminal provided on the end cap facilitates connection to an external power source, thereby improving the convenience of lithium replenishment. Using an external power source connected to the third terminal for lithium replenishment is not only fast but also convenient. Therefore, the battery cell of the present invention has the advantages of increased battery cycle life and convenient lithium replenishment.

[0022] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 A main view of a battery cell provided in an embodiment of the present application is shown.

[0026] Figure 2 A side view of a battery cell provided in an embodiment of the present application is shown.

[0027] Figure 3 A top view of a battery cell provided in an embodiment of the present application is shown.

[0028] Figure 4 Another top view of the battery cell provided in an embodiment of the present application is shown.

[0029] Figure 5 A schematic flow chart of a method for replenishing lithium in a battery cell provided in an embodiment of the present application is shown.

[0030] Reference numerals:

[0031] Battery cell 100;

[0032] Battery cell body 1; core 11; shell 13;

[0033] End cap 2; first pole 21; second pole 22; third pole 23;

[0034] Positive electrode 31 ; negative electrode 32 ; lithium-containing electrode 33 . DETAILED DESCRIPTION

[0035] In order to be able to more clearly understand the above-mentioned purposes, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In addition, in order to be able to understand the characteristics and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The accompanying drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of convenience of explanation, a full understanding of the disclosed embodiments is provided through a plurality of details. However, in the absence of these details, one or more embodiments can still be implemented. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0036] In order to improve the problem of insufficient lithium ion capacity caused by the large loss of active lithium in the current battery cell 100, this embodiment proposes a battery cell 100, a battery, a vehicle and a battery cell lithium replenishment method. Figures 1-4 A battery cell 100 according to an embodiment of the present invention is described.

[0037] The battery cell 100 includes a battery cell body 1, an end cap 2, a positive electrode 31, a negative electrode 32, and a lithium-containing electrode 33. The end cap 2 is provided at one end of the battery cell body 1, and the end cap 2 is provided with a first pole 21, a second pole 22, and a third pole 23; one end of each of the positive electrode 31, the negative electrode 32, and the lithium-containing electrode 33 is connected to the battery cell body 1, and the other end of each of the positive electrode 31, the negative electrode 32, and the lithium-containing electrode 33 is connected to the first pole 21, the second pole 22, and the third pole 23, respectively. Specifically, the first pole 21 is a positive pole, and the second pole 22 is a negative pole. The other end of the positive electrode 31 can be connected to the first pole 21, the other end of the negative electrode 32 can be connected to the second pole 22, and the other end of the lithium-containing electrode 33 can be connected to the third pole 23.

[0038] The battery cell 100 of the present invention is provided with a lithium-containing electrode 33, and the two ends of the lithium-containing electrode 33 are electrically connected to the battery cell body 1 and the end cap 2 (third pole 23). During the use of the battery cell 100, if a low capacitance problem is detected on the tab or the electrode sheet of the battery cell body 1, the lithium-containing electrode 33 can be used to replenish lithium. This solves the problem of poor cycle performance caused by large loss of active lithium after multiple charge and discharge cycles in the battery cell 100. Furthermore, the cycle life of the battery cell 100 is improved.

[0039] In addition, the third pole 23 provided on the end cover 2 facilitates connection with an external power source, which helps to improve the convenience of lithium replenishment operation.

[0040] Therefore, the battery cell 100 according to the embodiment of the present invention has the advantages of improving the cycle life of the battery and facilitating the lithium replenishment operation.

[0041] Optionally, the battery cell body 1 may include a core 11 , a shell 13 and an electrolyte (not shown), wherein the core 11 and the electrolyte are both disposed inside the shell 13 , and one end of the lithium-containing electrode 33 is immersed in the electrolyte.

[0042] Optionally, the battery cell body 1 may be a rolled core or a laminated core. The lithium-containing electrode 33 may be metallic lithium or a metallic lithium alloy.

[0043] Specifically, the end cap 2 includes an end cap body, a first pole 21, a second pole 22, and a third pole 23. The end cap body is provided with holes for the first pole 21, the second pole 22, and the third pole 23; the first pole 21, the second pole 22, and the third pole 23 are disposed in the holes for the first pole 21, the second pole 22, and the third pole 23 in a one-to-one correspondence.

[0044] The lithium-containing electrode 33 may be a lithium ribbon or a metal lithium foil.

[0045] The battery cell 100 of the embodiment of the present invention helps to increase the contact area between the lithium-containing electrode 33 and the electrode piece and the electrode column by setting the lithium-containing electrode 33 as a lithium strip or metal lithium foil, which helps to improve the efficiency and effect of lithium replenishment.

[0046] In this embodiment, the lithium content of the lithium-containing electrode 33 is 1 gram to 20 grams.

[0047] The battery cell 100 of the embodiment of the present invention can avoid the problem of poor lithium replenishment effect caused by the lithium-containing electrode 33 being too small and the problem of high production cost caused by the lithium-containing electrode 33 being too large by setting the lithium content of the lithium-containing electrode 33 to 1 gram to 20 grams.

[0048] Optionally, the mass of lithium element in the lithium-containing electrode 33 can be 1g, 2g, 3g, 4g, 5g, 6g, 7g, 8g, 9g, 10g, 11g, 12g, 13g, 14g, 15g, 16g, 17g, 18g, 19g or 20g.

[0049] The lithium-containing electrode comprises lithium by weight in a range of 25% to 100%. That is, the lithium-containing electrode comprises lithium by weight in a range of 25% to 100%. For example, the lithium-containing electrode is a lithium-containing alloy, such as a lithium-magnesium alloy, a lithium-aluminum alloy, or a lithium-magnesium-aluminum alloy. When the lithium-containing electrode is a lithium-magnesium alloy, the lithium-containing electrode comprises 25% by weight, and the magnesium-containing electrode comprises 75% by weight.

[0050] like Figure 1 、 Figure 3 and Figure 4As shown, the positive electrode 31, the negative electrode 32 and the lithium-containing electrode 33 are arranged along a predetermined direction (eg, Figure 1 The left and right directions shown in FIG are arranged on the battery cell body 1 at intervals.

[0051] The battery cell 100 of the embodiment of the present invention can improve the convenience of the structure by connecting the positive electrode 31 , the negative electrode 32 and the lithium-containing electrode 33 when the battery cell body 1 and the end cover 2 are installed.

[0052] For example, Figure 3 As shown, the positive electrode 31 , the lithium-containing electrode 33 and the negative electrode 32 are sequentially arranged on the battery cell body 1 at intervals along a preset direction of the lithium-containing electrode 33 .

[0053] The present application is not limited thereto. In other embodiments, Figure 4 As shown, the positive electrode 31 , the negative electrode 32 and the lithium-containing electrode 33 are sequentially arranged on the battery cell body 1 at intervals along a preset direction.

[0054] The lithium-containing electrode 33 serves as a complementary electrode to the negative electrode 32. The distance between the positive electrode 31 and the lithium-containing electrode 33 is greater than the distance between the lithium-containing electrode 33 and the negative electrode 32. This prevents the risk of circuit damage caused by interparticle interactions. Consequently, the battery cell 100 offers the advantage of high safety.

[0055] In some embodiments, the core 11 has at least two, and at least a portion of the lithium-containing electrode 33 is added between two adjacent cores 11, which can ensure a safe distance between the lithium-containing electrode 33 and the positive electrode 31 and the negative electrode 32, thereby avoiding the risk of interference caused by interaction between ions.

[0056] Furthermore, the negative electrode of the cell body 1 can be a lithium-rich negative electrode. The lithium-rich negative electrode, separator, and positive electrode are assembled into the cell body 1, the negative electrode 32 is connected to the lithium-rich negative electrode, and the positive electrode 31 is connected to the positive electrode.

[0057] The lithium-containing electrode 33 includes an electrode body and a connecting piece connected to each other. The connecting piece of the lithium-containing electrode 33 is connected to the lithium-containing electrode 33 through a hot-melt layer.

[0058] In the battery cell 100 of the embodiment of the present invention, the connection between the connecting piece and the lithium-containing electrode 33 is achieved through a hot melt layer. The connection method of the hot melt layer has the advantages of high installation convenience and good structural stability.

[0059] The lithium-containing electrode 33 connecting piece is welded to the third pole 23. The battery cell 100 of the embodiment of the present invention is welded to the third pole 23 by the lithium-containing electrode 33 connecting piece. The welding method has the advantage of good structural stability.

[0060] The connecting piece of the lithium-containing electrode 33 is a metal copper foil or a carbon-coated copper foil, and the thickness of the connecting piece of the lithium-containing electrode 33 is 4.5 microns to 20 microns. The use of copper connecting pieces can facilitate heat dissipation and has a cost advantage. Experimental data shows that a thickness between 4.5 microns and 20 microns is more appropriate, which avoids the advantages of the connecting piece being too thin to affect the fast charging capability and the thickness being too large to occupy a large space. Carbon-coated copper foil refers to coating the surface of the copper foil with a layer of black carbon powder, so that the copper foil is no longer reflective, and the surface is dark black, which can effectively absorb heat. Metal copper foil is the opposite, making the surface relatively bright and reflective, and has a certain heat-insulating effect.

[0061] This embodiment provides a method for replenishing lithium in a battery cell, the steps of which are: periodically collecting the lithium ion capacity of the target battery cell through a monitoring system; when the lithium ion capacity is lower than a preset capacity threshold; connecting the positive electrode of the external power supply to the lithium-containing electrode, and the negative electrode of the external power supply to the second pole, so that the lithium ions in the lithium-containing electrode 33 are replenished to the negative electrode 32 connected to the second pole 22; or, connecting the negative electrode of the external power supply to the lithium-containing electrode 33, and the positive electrode of the external power supply to the first pole 21, so that the lithium ions in the lithium-containing electrode 33 are replenished to the positive electrode 31 connected to the first pole 21.

[0062] The method for replenishing lithium in a battery cell provided in this embodiment only requires an external power source during the replenishment process. By switching the external power source's direct connection to different poles of the battery cell, lithium replenishment can be achieved for both the positive and negative electrodes of the battery cell. This method is highly convenient to operate and does not require complex external instruments or equipment for replenishment. This improves the convenience of lithium replenishment.

[0063] Going a step further, Figure 5 As shown, a schematic flow chart of a method for replenishing lithium in a battery cell provided in this embodiment includes:

[0064] S201 , periodically collecting the lithium ion capacity of the target battery cell 100 through a monitoring system.

[0065] The monitoring system here refers to a monitoring system that obtains the health status and lithium ion capacity of the battery cell 100, such as a BMS (Battery Management System). The target battery cell 100 is also the monitored battery cell 100, which is additionally provided with a lithium electrode 33.

[0066] S202 , when the lithium ion capacity is lower than a preset capacity threshold, the target battery cell 100 is adjusted to a discharge state, and the lithium-containing electrode 33 and the positive electrode 31 are discharged through an external power supply, so that the lithium ions are back-intercalated from the lithium-containing electrode 33 into the positive electrode 31 .

[0067] If the BMS detects that the capacity of a cell 100 is low, below a preset capacity threshold (e.g., 80%), lithium replenishment is required. The target cell 100 is adjusted to a discharged state, and the lithium-containing electrode 33 and the positive electrode 31 are discharged through the lithium-containing electrode 33, causing lithium ions to be embedded back into the positive electrode 31 from the lithium-containing electrode 33, thereby completing lithium replenishment of the positive electrode 31.

[0068] S203 , adjusting the target battery cell 100 to a charged state, charging the lithium-containing electrode 33 and the negative electrode, so that lithium ions are re-intercalated from the lithium-containing electrode 33 to the negative electrode.

[0069] The target cell 100 is then adjusted to a charged state, and the lithium-containing electrode 33 and the negative electrode are charged via the lithium-containing electrode 33, causing lithium ions to be intercalated from the lithium-containing electrode 33 into the graphite of the negative electrode, thereby completing the lithium replenishment of the negative electrode. This embodiment, by implanting the lithium-containing electrode 33 in the cell body 1, promptly replenishes lithium when the lithium ion content of the cell 100 is insufficient, thereby addressing the current problem of significant active lithium loss and insufficient lithium ion capacity in lithium battery cells 100 used for a long time.

[0070] That is to say, when the lithium replenishment cover plate and the negative electrode column of the top cover plate are connected to the external power supply at the same time, the lithium ions of the lithium source pass through the electrolyte to move to the negative electrode plate to be replenished, relying on the electrochemical reaction between the positive and negative electrodes, and are reduced by electrons on the negative electrode plate to generate metallic lithium, thereby achieving lithium replenishment; the lithium replenishment speed and amount can be controlled by adjusting the current and voltage values ​​of the external power supply as needed.

[0071] The charge cutoff voltage range for the positive electrode is 3.55V to 3.65V, and the charge cutoff voltage range for the negative electrode is 0.01V to 0.03V. By accurately controlling the charge cutoff voltage ranges of the positive and negative electrodes, the amount of lithium replenishment can be precisely controlled, thereby achieving precise and controllable pre-lithiation.

[0072] The lithium ion capacity of the battery cell is 100Ah to 200Ah. This can achieve the lithium replenishment effect on the positive and negative electrodes of most battery cells, avoiding excessive lithium ion residue inside the battery cell.

[0073] The preset capacity threshold is 75% to 90% of the lithium-ion capacity. This allows for timely lithium replenishment of the battery cell, preventing prolonged lithium deficiency from impacting the battery life. This improves the current problem of significant active lithium loss and insufficient lithium-ion capacity in long-term lithium battery cells.

[0074] Based on the above Figures 1 to 4 The structure shown and Figure 5 In order to achieve the above purpose, the present application also provides a battery which can be configured on the vehicle side, etc., and can specifically include the above Figure 1The battery cell 100 is shown.

[0075] Based on the above-mentioned lithium battery, the embodiment of the present application further provides a vehicle. Therefore, the lithium battery of the embodiment of the present invention has the advantages of improving the cycle life of the battery and facilitating the lithium replenishment operation.

[0076] Specifically, it may include: Figure 1 The battery cell 100 shown is a lithium battery as described above. The vehicle can be a new energy vehicle or a traditional vehicle.

[0077] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0078] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined. In this application, unless otherwise specified or defined, terms such as "mounted," "connected," "connected," and "fixed" should be interpreted broadly. For example, they may refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. A person of ordinary skill in the art will understand the specific meanings of these terms in this application based on the specific circumstances. Furthermore, the term "comprising" or any other variant thereof is intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. Without further constraints, an element defined by the phrase "comprises a..." does not preclude the existence of additional identical elements in the process, method, article or apparatus that includes the element.

[0079] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand and implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments described herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

[0080] The above description and accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. The embodiments represent only possible variations. Unless expressly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replaced with portions and features of other embodiments. As used in this application, the term "and / or" means including any and all possible combinations of one or more associated listed items. In addition, when used in this application, the term "comprise" and its variations "comprises" and / or comprising refer to the presence of the stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groups thereof. Without further limitation, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or device that includes the element. In this document, each embodiment may focus on the differences from other embodiments, and similar parts between the embodiments can be referenced. For methods, devices, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can be referenced in the description of the method part.

Claims

1. A battery cell, characterized in that: include: Battery cell body; An end cover is provided at one end of the battery cell body, and the end cover is provided with a first pole, a second pole and a third pole; and A positive electrode, a negative electrode and a lithium-containing electrode, one end of each of the positive electrode, the negative electrode and the lithium-containing electrode is connected to the battery body, the other end of the positive electrode is connected to the first pole, the other end of the negative electrode is connected to the second pole, and the other end of the lithium-containing electrode is connected to the third pole.

2. The battery cell according to claim 1, characterized in that The lithium-containing electrode is a lithium strip or a metal lithium foil, and / or the lithium content of the lithium-containing electrode is 1 gram to 20 grams; And / or, the mass percentage of lithium element in the lithium-containing electrode is in the range of 25% to 100%.

3. The battery cell according to claim 1, characterized in that The battery cell body comprises a core, an electrolyte and a shell. The core and the electrolyte are both arranged inside the shell, and one end of the lithium-containing electrode is immersed in the electrolyte.

4. The battery cell according to claim 3, characterized in that There are at least two core bodies, and at least a portion of the lithium-containing electrode is sandwiched between two adjacent core bodies, or at least a portion of the lithium-containing electrode is sandwiched between the shell and the outermost core body.

5. The battery cell according to claim 4, characterized in that: The positive electrode, the lithium-containing electrode and the negative electrode are sequentially arranged on the core body at intervals along a preset direction, and the distance between the positive electrode and the lithium-containing electrode is greater than the distance between the lithium-containing electrode and the negative electrode.

6. The battery cell according to claim 1, characterized in that The lithium-containing electrode comprises an electrode body and a connecting piece connected to each other, wherein the connecting piece is connected to the lithium-containing electrode via a hot melt layer; and / or the connecting piece is welded to the third pole.

7. A method for replenishing lithium in a battery cell, characterized in that: Applicable to the battery cell according to any one of claims 1 to 6; the method comprising: The lithium ion capacity of the target battery cell is periodically collected through a monitoring system; when the lithium ion capacity is lower than a preset capacity threshold, the positive electrode of the external power supply is connected to the lithium-containing electrode, and the negative electrode of the external power supply is connected to the second pole, so that the lithium ions in the lithium-containing electrode are replenished to the negative electrode connected to the second pole; or, the negative electrode of the external power supply is connected to the lithium-containing electrode, and the positive electrode of the external power supply is connected to the first pole, so that the lithium ions in the lithium-containing electrode are replenished to the positive electrode connected to the first pole.

8. The method for replenishing lithium in a battery cell according to claim 7, wherein: The charging cut-off voltage range for the positive electrode is 3.55V to 3.65V, and the charging cut-off voltage range for the negative electrode is 0.01V to 0.03V; And / or, the lithium ion capacity of the battery cell is 100 Ah to 200 Ah, and the preset capacity threshold is 75% to 90% of the lithium ion capacity.

9. A battery, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 6.

10. A vehicle, characterized in that: The vehicle comprises a vehicle body and the battery cell according to any one of claims 1 to 6 or the battery according to claim 9.

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