Lithium supplementing method for electrode assembly
The lithium replenishment method using an electrode assembly with gradient discharge rate and through-hole design resolves the contradiction between effect and time during the pre-lithiation process of the electrode assembly, achieving uniform lithium ion distribution and shortening the reaction time.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG LIWINON ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-10
Smart Images
Figure CN121839944A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a method for replenishing lithium in an electrode assembly. Background Technology
[0002] With the development of new energy sources, more and more fields are adopting new energy as a power source. Due to their advantages such as high energy density, rechargeability, safety, and environmental friendliness, electrochemical devices are widely used in new energy vehicles, consumer electronics, and energy storage systems. In the preparation process of electrochemical devices, the electrode components need to be pre-lithiated.
[0003] In related technologies, the pre-lithiation process of electrode components cannot simultaneously address the issues of pre-lithiation effect and reaction time. Summary of the Invention
[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a lithium replenishment method for electrode components that can simultaneously address the issues of pre-lithiation effect and reaction time in the pre-lithiation process of the electrode components.
[0005] A lithium replenishment method for an electrode assembly according to a first aspect embodiment of this application, the electrode assembly including a lithium replenishment electrode, a first electrode, and a second electrode, wherein the first electrode is located between the lithium replenishment electrode and the second electrode along the thickness direction of the electrode assembly, the lithium replenishment method comprising: The electrode assembly is discharged at a first rate for a first duration; The electrode assembly is discharged at a second rate until the capacity of the electrode assembly reaches a preset capacity. The second multiplier is greater than the first multiplier.
[0006] The lithium replenishment method for the electrode assembly according to the embodiments of this application has at least the following beneficial effects: In the scheme of this application embodiment, during the lithium replenishment process of the electrode assembly, the electrode assembly needs to be discharged. The lithium replenishment electrode, acting as the negative electrode, is oxidized, releasing lithium ions and electrons. The first electrode, acting as the positive electrode, receives electrons and inserts lithium ions. During the discharge process, the electrode assembly is first discharged at a first rate, and then discharged at a larger second rate. During the discharge process at the first rate, the lithium ion extraction rate is slower, the electrochemical reaction inside the electrode assembly is milder, the polarization phenomenon is weaker, and the voltage change is more stable. This facilitates more precise control of the amount and process of lithium ion extraction, resulting in more uniform lithium ion deposition on the surface of the first electrode. When a relatively uniform SEI (Solid Electrolyte Interphase) film is initially formed on the surface of the first electrode, the discharge rate can be increased, thereby accelerating the lithium ion extraction rate, reducing the discharge process time, and thus reducing the time consumed in the lithium replenishment process. The embodiments of this application, by discharging through gradient discharge rates, enable the electrode assembly to achieve a better pre-lithiation effect at different stages and shorten the reaction time.
[0007] According to some embodiments of this application, prior to the step of attaching the lithium replenishment electrode to the first electrode, the lithium replenishment method further includes: An opening is made in at least one of the first electrode and the second electrode to form a through hole.
[0008] According to some embodiments of this application, the designed diameter of the through hole is greater than or equal to 10 μm and less than or equal to 30 μm.
[0009] According to some embodiments of this application, the step of making a hole in at least one of the first electrode and the second electrode includes: Multiple through holes are formed in the first electrode sheet, projected along the thickness direction of the electrode assembly. The distance between two adjacent through holes is greater than or equal to 0.8 mm and less than or equal to 1.5 mm, and / or... Multiple through holes are made in the second electrode, projected squarely along the thickness of the electrode assembly, with the spacing between two adjacent through holes being greater than or equal to 0.8 mm and less than or equal to 1.5 mm.
[0010] According to some embodiments of this application, the step of making a hole in at least one of the first electrode and the second electrode includes: Holes are made in both the first electrode and the second electrode to form through holes; Wherein, the through hole corresponding to the first electrode is a first opening, and the through hole corresponding to the second electrode is a second opening, the central axis of the first opening overlaps with the central axis of the second opening. According to some embodiments of this application, after the step of discharging the electrode assembly at a first rate, the lithium replenishment method further includes: The electrode assembly is discharged at a third rate for a second duration; Wherein, the third multiplier is greater than the first multiplier, and the third multiplier is less than the second multiplier.
[0011] According to some embodiments of this application, the first multiplier is greater than or equal to 0.04C and less than or equal to 0.08C, and / or the second multiplier is greater than or equal to 0.40C and less than or equal to 0.60C, and / or the third multiplier is less than or equal to 0.20C and less than or equal to 0.30C.
[0012] According to some embodiments of this application, after the step of discharging the electrode assembly at a second rate, the lithium replenishment method further includes: The electrode assembly is left to stand for a third time.
[0013] According to some embodiments of this application, the third duration is greater than or equal to 100h and less than or equal to 120h.
[0014] According to some embodiments of this application, the step of resting the electrode assembly for a third time period includes: Heat the electrode assembly to a preset temperature; The electrode assembly is maintained at the preset temperature for the third duration. The preset temperature is greater than or equal to 65°C and less than or equal to 85°C.
[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0016] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic flowchart of a lithium replenishment method for an electrode assembly in one embodiment of this application; Figure 2 This is a schematic flowchart of a lithium replenishment method for an electrode assembly in another embodiment of this application; Figure 3 This is a simplified structural diagram of an electrode assembly in one embodiment of this application.
[0017] Figure label: 100, Lithium-replenishing electrode; 200, First electrode; 200a, First opening; 300, Second electrode; 300a, Second opening; 400, Separator. Detailed Implementation
[0018] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0019] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0020] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0021] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.
[0022] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0023] Currently, judging from market trends, the application of electrochemical devices is becoming increasingly widespread. Electrochemical devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of the application areas of electrochemical devices, the market demand is also constantly increasing.
[0024] In related technologies, the electrode assembly needs to be pre-lithiated during the fabrication of electrochemical devices. After the lithium replenishment electrode is attached to the electrode assembly, the electrode assembly needs to be discharged to allow lithium ions in the lithium replenishment electrode to migrate to the electrode assembly. During the discharge of the electrode assembly, a fixed discharge rate is typically used. At higher discharge rates, the lithium ion extraction rate is relatively fast, completing the entire discharge process in a shorter time; however, the polarization phenomenon inside the electrode assembly is more pronounced, the voltage drops more rapidly, and the lithium replenishment effect is poor. At lower discharge rates, the electrochemical reaction inside the electrode assembly is milder, the polarization phenomenon is weaker, and the voltage change is more gradual; however, the overall discharge process takes longer.
[0025] In the process of replenishing lithium to the electrode assembly, the present application embodiment discharges at a gradient rate, thereby taking into account the advantages of both a small and large discharge rate, and thus solving the problems of pre-lithiation effect and reaction time.
[0026] This application provides an electronic device, which includes a device body and an electrochemical device for supplying power to the device body.
[0027] Electronic devices can be, for example, mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft.
[0028] The technical solutions described in the embodiments of this application are not limited to the devices described above, but can also be applied to all devices that use electrochemical devices.
[0029] The electrochemical devices mentioned in the embodiments of this application may include one or more electrochemical device assemblies for providing voltage and capacity. An electrochemical device assembly may include multiple electrochemical devices, which are connected in series, parallel, or mixed configurations via a busbar.
[0030] In some embodiments, the electrochemical device assembly is typically formed by arranging multiple electrochemical devices.
[0031] As an example, the electrochemical device assembly can be a battery module, which consists of multiple electrochemical devices arranged and fixed together to form a single module. As another example, a battery module can be formed by bundling multiple electrochemical devices together with cable ties.
[0032] In some embodiments, the electrochemical device may be a battery pack, which includes a housing and one or more electrochemical device components housed within the housing.
[0033] This application also provides a battery pack, which includes a housing and at least one electrochemical device located inside the housing.
[0034] In some embodiments of this application, the electrochemical device can be a secondary battery, which refers to an electrochemical device that can be used again after being discharged by recharging to activate the active material.
[0035] The electrochemical device can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.
[0036] This application provides a method for lithium replenishment of an electrode assembly. Please refer to [link to relevant documentation]. Figure 1 and Figure 2 The electrode assembly includes a lithium replenishment electrode 100, a first electrode 200, and a second electrode 300. Along the thickness direction of the electrode assembly, the first electrode 200 is located between the lithium replenishment electrode 100 and the second electrode 300. The lithium replenishment method includes: Step S1: Discharge the electrode assembly at a first rate and continue for a first duration; Step S2: Discharge the electrode assembly at a second rate until the capacity of the electrode assembly reaches the preset capacity; wherein the second rate is greater than the first rate.
[0037] For example, the first electrode 200 can be a negative electrode, the second electrode 300 can be a positive electrode, and the electrode assembly also includes a separator 400. A separator 400 is provided between the lithium supplement electrode 100, the negative electrode, and the positive electrode. The type of the electrode assembly can be a stacked cell.
[0038] In the embodiment of this application, during the lithium replenishment process of the electrode assembly, the electrode assembly needs to be discharged. The lithium replenishment electrode 100, acting as the negative electrode, is oxidized, releasing lithium ions and electrons. The first electrode 200, acting as the positive electrode, receives electrons and inserts lithium ions. During the discharge process, the electrode assembly is first discharged at a first rate, and then discharged at a larger second rate. During the discharge process at the first rate, the lithium ion extraction rate is relatively slow, the electrochemical reaction inside the electrode assembly is relatively mild, the polarization phenomenon is weak, and the voltage change is relatively stable. This facilitates more precise control of the amount and process of lithium ion extraction, resulting in more uniform deposition of lithium ions on the surface of the first electrode 200. When a relatively uniform SEI film is initially formed on the surface of the first electrode 200, the discharge rate can be increased, thereby accelerating the extraction rate of lithium ions, reducing the discharge process time, and thus reducing the time consumed in the lithium replenishment process. The embodiment of this application, by discharging at a gradient discharge rate, enables the electrode assembly to achieve a better pre-lithiation effect at different stages and shortens the reaction time.
[0039] In one embodiment, please refer to Figure 1 Before the step of attaching the lithium replenishment electrode 100 to the first electrode 200, the lithium replenishment method further includes: Step S3: Make a hole in at least one of the first electrode and the second electrode to form a through hole.
[0040] For example, when a through-hole is formed in the first electrode 200, the through-hole extends through the first electrode 200 along the thickness direction of the electrode assembly; when a through-hole is formed in the second electrode 300, the through-hole extends through the second electrode 300 along the thickness direction of the electrode assembly. The through-hole provides a unique channel and reaction site for the lithium replenishment process. Lithium ions, starting from the lithium replenishment electrode 100, can move through the through-hole formed by the first electrode 200 and the second electrode 300, thereby moving between different electrodes. The through-hole shortens the migration distance of lithium ions, thereby improving the lithium replenishment efficiency and the uniformity of lithium ion distribution. For example, the thickness direction of the electrode assembly is as follows... Figure 3 The direction indicated by the middle arrow R3. Furthermore, the through-hole provides a buffer space for the volume expansion of the electrode assembly during charging and discharging, reducing the risk of cracking and decomposition caused by repeated volume changes under internal stress. The combination of the through-hole and gradient discharge rate can simultaneously solve the problems of low lithium-ion transport efficiency, high initial lithium loss, and poor cycle stability.
[0041] Understandably, perforations in electrodes can be created by using drilling tools (such as punches) or energy tools (such as lasers) to penetrate downwards from the active material layer. In terms of shape, the perforations can be circular, square, honeycomb-like, or other irregular stripes. The applicant of this application found through research that circular perforations result in more uniform force distribution and transmission paths, hence their adoption. However, during processing, the perforated channels are not standard cylindrical shapes. As the drilling tool penetrates downwards from the active material layer, it is continuously absorbed, dispersed, and consumed by the powder particles along the way. The surface of the active material layer experiences the greatest energy or force, capable of pushing more particles outwards, thus forming a larger initial pore size. As energy attenuates through the intermediate layers, its ability to push particles decreases, making it difficult to form pores of the same size as the surface, leading to pore shrinkage. Therefore, during the drilling process of the first electrode 200 or the second electrode 300, the actual channel formed is a frustum plus cylinder structure. If the diameter of the through hole is too small, powder will clog the hole, which will affect the lithium ion transport path. If the diameter of the through hole is too large, it will reduce the active material loading and result in insufficient energy density of the electrode assembly.
[0042] In one embodiment, the designed aperture of the through-hole is greater than or equal to 10 μm and less than or equal to 30 μm. Exemplarily, the through-hole is circular in shape, and its designed aperture can be 10 μm, 15 μm, 20 μm, 25 μm, or 30 μm. The applicant's research has shown that the actual aperture produced during the drilling process differs slightly from the designed aperture. Setting the designed aperture of the through-hole between 10 μm and 30 μm allows lithium ions to migrate more smoothly within the channels formed by the through-hole, while also reducing the impact of the through-hole on the energy density of the electrode assembly to a certain extent.
[0043] In one embodiment, the step of making an opening in at least one of the first electrode 200 and the second electrode 300 includes: Step S30: Multiple through holes are formed in the first electrode plate, projected along the thickness direction of the electrode assembly. The distance between two adjacent through holes is greater than or equal to 0.8 mm and less than or equal to 1.5 mm, and / or... Step S31: Make multiple through holes in the second electrode plate, projected squarely along the thickness of the electrode assembly, with the distance between two adjacent through holes being greater than or equal to 0.8 mm and less than or equal to 1.5 mm.
[0044] It is understandable that when the through-hole is circular, the distance between two adjacent through-holes is the distance between their central axes. Within a suitable range, the distance between two adjacent through-holes can not only improve rate performance but also reduce capacity loss in the electrode assembly to some extent.
[0045] In one embodiment, the aperture ratio of the first electrode 200 and / or the second electrode 300 is 0.5% to 1.5%. The aperture ratio of the first electrode 200 and / or the second electrode 300 can be 0.5%, 0.7%, 0.9%, 1.0%, 1.2%, 1.4%, or 1.5%. Exemplarily, projecting along the thickness direction of the electrode assembly, the area of the projected region of all the through holes corresponding to the first electrode 200 is the first area, and the area of the projected region of the first electrode 200 is the second area. The ratio of the first area to the second area is the aperture ratio of the first electrode 200, and the aperture ratio of the second electrode 300 follows the same principle. Within a suitable range, the aperture ratios of the first electrode 200 and the second electrode 300 can achieve high lithium-ion migration efficiency while reducing the impact of apertures on the capacity of the electrode assembly.
[0046] In one embodiment, please refer to Figure 3 The step of making an opening in at least one of the first electrode 200 and the second electrode 300 includes: Step S32: Make holes in both the first and second electrodes to form through holes; In this design, the through hole corresponding to the first electrode 200 is a first opening 200a, and the through hole corresponding to the second electrode 300 is a second opening 300a. The central axis of the first opening 200a overlaps with the central axis of the second opening 300a. For example, the designed aperture of the first opening 200a is equal to the designed aperture of the second opening 300a. Both the first electrode 200 and the second electrode 300 have through holes, and the first opening 200a and the second opening 300a are aligned along the thickness direction of the electrode assembly. This further reduces the migration distance of lithium ions, thereby improving lithium replenishment efficiency and resulting in a more uniform distribution of lithium ions.
[0047] In one embodiment, please refer to Figure 1 After discharging the electrode assembly at the first rate, the lithium replenishment method further includes: Step S4: Discharge the electrode assembly at the third rate and continue for the second duration; Among them, the third multiplier is greater than the first multiplier, and the third multiplier is less than the second multiplier.
[0048] For example, the first duration is greater than or equal to 10 hours and less than or equal to 14 hours. Within a suitable range, the first duration allows for a relatively stable initial formation of the SEI film on the surface of the first electrode 200, while also increasing the efficiency of the lithium replenishment process to a certain extent. The second duration is greater than or equal to 4 hours and less than or equal to 8 hours. The first duration can be 10 hours, 11 hours, 12 hours, 13 hours, or 14 hours. The second duration can be 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours. In the step of discharging the electrode assembly at the first rate, constant current discharge is used, with a cutoff voltage of 0.05V. In the step of discharging the electrode assembly at the third rate, constant current discharge is still used, with a cutoff voltage of 0.05V. In the step of discharging the electrode assembly at the second rate, discharge is first performed with a constant current until the voltage reaches 0.05V. After the voltage reaches 0.05V, discharge continues with a constant current and constant voltage until the capacity of the electrode assembly reaches a preset capacity, which can be 0.02C.
[0049] In the embodiment of this application, a third rate is added between the first rate and the second rate to refine the rate gradient change, thereby further balancing the pre-lithiation effect and the reaction time issue, further improving the uniformity of the SEI film, and further shortening the pre-lithiation reaction time.
[0050] In one embodiment, the first rate of discharge is greater than or equal to 0.04C and less than or equal to 0.08C, and the first rate of discharge can be 0.04C, 0.05C, 0.06C, 0.07C, or 0.08C. The second rate of discharge is greater than or equal to 0.40C and less than or equal to 0.60C, and the second rate of discharge can be 0.40C, 0.45C, 0.50C, 0.55C, or 0.60C. The third rate of discharge is less than or equal to 0.20C and less than or equal to 0.30C, and the third rate of discharge can be 0.20C, 0.25C, or 0.30C. When the first, second, and third rates are within a suitable range, the surface of the first electrode 200 can achieve both uniformity and formation efficiency during the formation of the SEI film, resulting in a more uniform distribution of lithium ions and a shorter processing time. It is understood that a first rate of discharge of 0.05C means that the electrode assembly is discharging at 5% of its rated capacity.
[0051] In one embodiment, please refer to Figure 1 After discharging the electrode assembly at a second-highest rate, the lithium replenishment method further includes: Step S5: Allow the electrode assembly to stand for a third time. Allowing the electrode assembly to stand after discharge utilizes the concentration gradient as a driving force to promote the spontaneous migration and redistribution of lithium ions. Lithium ions can migrate from the first electrode 200 to other electrodes in the electrode assembly, thereby achieving a uniform lithium replenishment effect.
[0052] In one embodiment, the third duration is greater than or equal to 100 hours and less than or equal to 120 hours. Exemplarily, the third duration can be 100 hours, 105 hours, 110 hours, 115 hours, or 120 hours. Lithium ions require a certain amount of time to overcome transport resistance and complete interlayer migration. A third duration within a suitable range allows lithium ions to achieve a basic distribution equilibrium in the multilayer electrode, while also controlling the time consumed in the lithium replenishment process to a certain extent.
[0053] In one embodiment, please refer to Figure 2 The step of allowing the electrode assembly to rest for a third time includes: Step S50: Heat the electrode assembly to a preset temperature; Step S51: Maintain the electrode assembly at the preset temperature for a third duration; The preset temperature is greater than or equal to 65°C and less than or equal to 85°C. For example, the preset temperature can be 65°C, 70°C, 75°C, 80°C, or 85°C. Heating the electrode assembly enhances the activity of the electrolyte, increases the diffusion coefficient of lithium ions, and accelerates the diffusion rate. A preset temperature within a suitable range allows for high electrolyte activity, rapid lithium ion diffusion, and, within this range, the formed SEI film exhibits good density and stability, while also reducing electrolyte decomposition and vaporization to a certain extent. It is understood that heating the electrode assembly can be done directly or indirectly, such as placing the electrochemical device corresponding to the electrode assembly within a heating device.
[0054] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and all should be covered within the scope of the specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of protection.
Claims
1. A method for lithium replenishment of an electrode assembly, characterized in that, The electrode assembly includes a lithium replenishment electrode, a first electrode, and a second electrode. Along the thickness direction of the electrode assembly, the first electrode is located between the lithium replenishment electrode and the second electrode. The lithium replenishment method includes: The electrode assembly is discharged at a first rate for a first duration; The electrode assembly is discharged at a second rate until the capacity of the electrode assembly reaches a preset capacity. The second multiplier is greater than the first multiplier.
2. The lithium replenishment method according to claim 1, characterized in that, Before the step of attaching the lithium replenishment electrode to the first electrode, the lithium replenishment method further includes: An opening is made in at least one of the first electrode and the second electrode to form a through hole.
3. The lithium replenishment method according to claim 2, characterized in that, The designed diameter of the through hole is greater than or equal to 10 μm and less than or equal to 30 μm.
4. The lithium replenishment method according to claim 2, characterized in that, The step of making an opening in at least one of the first electrode and the second electrode includes: Multiple through holes are formed in the first electrode sheet, projected along the thickness direction of the electrode assembly. The distance between two adjacent through holes is greater than or equal to 0.8 mm and less than or equal to 1.5 mm, and / or... Multiple through holes are made in the second electrode, projected squarely along the thickness of the electrode assembly, with the spacing between two adjacent through holes being greater than or equal to 0.8 mm and less than or equal to 1.5 mm.
5. The lithium replenishment method according to claim 1, characterized in that, The step of making an opening in at least one of the first electrode and the second electrode includes: Holes are made in both the first electrode and the second electrode to form through holes; Wherein, the through hole corresponding to the first electrode is the first opening, the through hole corresponding to the second electrode is the second opening, and the central axis of the first opening overlaps with the central axis of the second opening.
6. The lithium replenishment method according to claim 1, characterized in that, After discharging the electrode assembly at the first rate, the lithium replenishment method further includes: The electrode assembly is discharged at a third rate for a second duration; Wherein, the third multiplier is greater than the first multiplier, and the third multiplier is less than the second multiplier.
7. The lithium replenishment method according to claim 6, characterized in that, The first multiplier is greater than or equal to 0.04C and less than or equal to 0.08C, and / or the second multiplier is greater than or equal to 0.40C and less than or equal to 0.60C, and / or the third multiplier is less than or equal to 0.20C and less than or equal to 0.30C.
8. The lithium replenishment method according to claim 1, characterized in that, After discharging the electrode assembly at a second rate, the lithium replenishment method further includes: The electrode assembly is left to stand for a third time.
9. The lithium replenishment method according to claim 8, characterized in that, The third duration is greater than or equal to 100h and less than or equal to 120h.
10. The lithium replenishment method according to claim 1, characterized in that, The step of resting the electrode assembly for a third time period includes: Heat the electrode assembly to a preset temperature; The electrode assembly is maintained at the preset temperature for the third duration. The preset temperature is greater than or equal to 65°C and less than or equal to 85°C.