CN117996215A

CN117996215A - Battery, preparation method thereof and electricity utilization device

Info

Publication number: CN117996215A
Application number: CN202410405800.5A
Authority: CN
Inventors: 常雯; 付成华; 郭锁刚; 谢庭祯; 朱畅; 朱小刚; 陈辉
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2024-04-07
Filing date: 2024-04-07
Publication date: 2024-05-07

Abstract

The application relates to a battery, a preparation method thereof and an electric device, wherein the preparation method of the battery comprises the following steps: drying the battery without liquid injection, sequentially carrying out primary liquid injection and primary formation treatment, and preparing a battery after pre-formation; performing secondary liquid injection on the battery after the pre-formation, and performing secondary formation treatment until the battery reaches a preset charge state to prepare the battery; the method comprises the steps of charging a battery subjected to primary liquid injection to a first charge state at a first multiplying power constant current, and then charging the battery to a second charge state at a second multiplying power constant current; wherein the first magnification is smaller than the second magnification; the first state of charge is less than a second state of charge, which is less than the predetermined state of charge. According to the method, even if no extra high-temperature standing step is carried out after one-time liquid injection, the battery with excellent electrical performance can be prepared, the preparation time is shortened, and the preparation efficiency is improved.

Description

Battery, preparation method thereof and electricity utilization device

Technical Field

The invention relates to the technical field of batteries, in particular to a battery, a preparation method thereof and an electric device.

Background

In recent years, secondary batteries such as lithium ion batteries have been widely used in various fields such as energy storage power systems for hydraulic power, thermal power, wind power, and solar power stations, electric tools, electric bicycles, electric motorcycles, electric automobiles, military equipment, and aerospace.

The formation is an important process in the production process of secondary batteries such as lithium ion batteries, and mainly comprises the steps of formation by charging, activating internal positive and negative electrode substances by means of current, or forming an SEI film on the surface of a negative electrode, so that the battery performance is more stable, and the purposes of improving the electrical performance, the safety performance and the cycle performance of the secondary batteries are achieved. However, in the conventional battery preparation process, the battery is usually required to be kept at a high temperature for a long time before being charged, the process flow is complex, the period is long, the self-discharge change of the formed battery is large, the efficiency of the secondary battery in the production process is reduced, and the energy consumption is large.

Accordingly, the conventional technology is required to be further improved.

Disclosure of Invention

Based on the above, the application provides a battery, a preparation method thereof and an electric device.

The application is realized by the following technical scheme.

In a first aspect of the present application, there is provided a method for manufacturing a battery, comprising the steps of:

drying the battery without liquid injection, sequentially carrying out primary liquid injection and primary formation treatment, and preparing a battery after pre-formation;

Performing secondary liquid injection on the battery after the pre-formation, and performing secondary formation treatment until the battery reaches a preset charge state to prepare the battery;

Wherein, the primary formation treatment comprises the following steps:

The battery after the primary liquid injection is charged to a first charge state with a constant current of a first multiplying power, and then is charged to a second charge state with a constant current of a second multiplying power; the first state of charge is less than the second state of charge, which is less than the predetermined state of charge;

after the step of injecting liquid once and before the step of forming treatment once, the method further comprises the following steps:

Standing the battery subjected to primary liquid injection at 20-30 ℃ for 1-5 min;

The second charge state is 15-19% of SOC.

In the preparation process of the battery, the battery after the drying treatment is injected once, a certain residual heat is still reserved in the battery after the drying treatment, the residual heat can promote the electrolyte to infiltrate the pole pieces, the subsequent formation is facilitated, the battery after the primary injection is subjected to the primary formation treatment under specific conditions, wherein the battery is firstly charged to a first charge state by constant current at a first multiplying power, then charged to a second charge state by constant current at a second multiplying power, the first multiplying power is controlled to be smaller than the second multiplying power, the battery is charged at a smaller multiplying power, active substances of the battery are fully activated to promote the generation of SEI films, then the charging at a larger multiplying power is further promoted, the film forming reaction of the electrolyte between the pole pieces is further promoted to be complete, lithium precipitation is reduced while the SEI films are perfected, and the secondary injection and the secondary formation treatment are performed. Therefore, even if no extra high-temperature standing step is carried out after one-time liquid injection, the battery with excellent electrical performance can be prepared, the preparation time is shortened, and the preparation efficiency is improved.

In some embodiments, the first multiplying power is 0.02 c-0.1 c.

In some embodiments, the first multiplying power is 0.04c to 0.08c.

The first multiplying power is further regulated, and when the charging time is further shortened, the probability of increasing the polarization degree caused by higher multiplying power charging is reduced.

In the preparation process of the battery, if certain conditions are not met, for example, the water content exceeds the standard, the self-discharge curve of the battery is abnormal, namely the voltage is suddenly reduced or increased, so that abnormal defective products in the preparation process can be detected by utilizing the characteristics, but if the polarization degree is high in the preparation process, the abnormal self-discharge curve of the battery is caused, namely the measured actual electrode potential deviates from the balance electrode potential due to the charging condition with high multiplying power, and the measured voltage instantaneously deviates from the actual voltage. Therefore, when the defective products are detected by the self-discharge change degree, the excessively high polarization can interfere the results, so that the accuracy of the screening results is reduced, in the preparation process of the battery, the battery is charged by a small multiplying power, the polarization degree is small, the influence of the polarization on the follow-up detection of the defective products of the battery by the self-discharge change degree of the battery can be reduced, and the detection of the abnormal battery is facilitated.

In some embodiments, the second multiplying power is 0.33 c-1 c.

And the second multiplying power is further regulated, and when the charging time is further shortened, the probability of occurrence of lithium precipitation or black spots in a weak area (such as a pole piece thinning area or a corner) of the battery is reduced.

In some embodiments, the preparation method satisfies at least one of the following conditions (1) - (2):

(1) The first state of charge is less than or equal to 2% SOC;

(2) The predetermined state of charge is greater than or equal to 60% SOC.

And further controlling the end point state of the first charge state or the second charge state, namely, charging to a specific end point charge state with a smaller multiplying power, fully activating the battery active substance to promote the generation of an SEI film, and then charging to the specific end point charge state with a larger multiplying power, further promoting the film forming reaction of the electrolyte between the pole pieces to be complete, and reducing lithium precipitation while perfecting the SEI film.

In some of these embodiments, the first state of charge is: 1% SOC to 2% SOC.

In some of these embodiments, the secondary chemical conversion process is performed as follows:

And charging the battery subjected to secondary liquid injection to the preset charge state at a constant current of 0.33-1 ℃.

(1) After the step of constant current charging to a first state of charge at a first rate and before the step of constant current charging at a second rate, the method further comprises the steps of:

Standing the battery charged to the first charge state at the first multiplying power constant current at 20-30 ℃ for 3-10 min;

(2) After the step of primary formation treatment and before the step of secondary injection, the method further comprises the following steps:

and standing the battery subjected to the pre-formation at 20-30 ℃ for 1 min-5 min.

In some embodiments, the preparation method of the battery meets at least one of the following conditions (1) - (2):

(1) The temperature of the primary formation treatment is 25-45 ℃;

the temperature of the primary formation treatment is regulated and controlled, which is beneficial to the formation of SEI film.

(2) The primary formation treatment is carried out in a negative pressure environment.

The formation process inevitably produces byproduct gas, and the negative pressure environment is favorable for exhaust.

In some embodiments, the relative pressure of the negative pressure environment is-20 Kpa to-0.2 Kpa.

(1) The electrolyte adopted in the primary liquid injection treatment contains a film forming agent;

In the primary formation treatment, the formation of the SEI film is mainly promoted, and a film forming agent is added into the electrolyte adopted in the process, so that the formation and perfection of the SEI film are facilitated.

(2) And taking the total mass of the electrolyte adopted by the primary liquid injection treatment and the electrolyte adopted by the secondary liquid injection treatment as a reference, wherein the mass ratio of the electrolyte adopted by the primary liquid injection treatment is 80% -90%.

In some embodiments, the temperature of the drying process is 95 ℃ to 115 ℃.

The battery after the drying treatment still keeps certain residual heat, and when the battery is directly injected with the electrolyte, the residual heat can promote the electrolyte to infiltrate the pole piece, thereby being beneficial to subsequent formation.

In some embodiments, after the step of secondary formation, the method further includes a step of aging the secondary formation-treated battery.

In some of these embodiments, the aging treatment is at a temperature of 45 ℃ ± 5 ℃ for a time of 48h ±2 hours.

In a second aspect of the present application, there is provided a method for manufacturing a battery of the first aspect, comprising the steps of:

in a third aspect of the application, there is provided an electrical device comprising the battery of the first aspect.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the accompanying drawings. In the drawings:

Fig. 1 is a flow chart of the preparation of a battery in an embodiment;

FIG. 2 is a schematic diagram of one embodiment of a battery cell in one embodiment;

FIG. 3 is an exploded view of FIG. 2;

FIG. 4 is a schematic diagram of an embodiment of a battery pack;

FIG. 5 is an exploded view of FIG. 4;

fig. 6 is a schematic diagram of an embodiment of an electrical device with a battery as a power source.

Reference numerals illustrate:

1. A battery pack; 2. an upper case; 3. a lower box body; 4. a battery cell; 41. a housing; 42. an electrode assembly; 5. and (5) an electric device.

Detailed Description

The following detailed description of the present application will provide further details in order to make the above-mentioned objects, features and advantages of the present application more comprehensible. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In the present application, unless otherwise specified, "room temperature" generally means 10 ℃ to 30 ℃, preferably 20 ℃ + -5 ℃.

An embodiment of the application provides a preparation method of a battery, which comprises the following steps S10-S20.

Step S10: and drying the battery without liquid injection, and sequentially carrying out liquid injection and primary formation treatment to prepare the battery after the pre-formation.

Step S20: and (3) performing secondary liquid injection on the battery after the pre-formation, and performing secondary formation treatment until the battery reaches a preset charge state to prepare the battery.

Wherein, the primary formation treatment comprises the following steps:

And (3) carrying out constant-current charging on the battery subjected to primary liquid injection to a first charge state at a first multiplying power, and then carrying out constant-current charging on the battery to a second charge state at a second multiplying power.

Wherein the first magnification is smaller than the second magnification; the first state of charge is less than the second state of charge, which is less than the predetermined state of charge.

In some of these embodiments, the dried battery is directly subjected to one-shot injection.

Referring specifically to fig. 1, fig. 1 is a flowchart of a battery preparation process according to an embodiment, and specifically includes the following steps performed in sequence:

step S11: and (5) drying the battery without the liquid injection.

Step S12: and (5) injecting liquid once.

Step S13: and (3) carrying out primary formation treatment: and (3) carrying out constant-current charging on the battery subjected to primary liquid injection to a first charge state at a first multiplying power, and then carrying out constant-current charging on the battery subjected to secondary liquid injection to a second charge state at a second multiplying power, so as to prepare the battery subjected to pre-formation.

Step S21: and (5) performing secondary injection on the battery after the pre-formation.

Step S22: and performing secondary formation treatment until the predetermined charge state is reached.

In some embodiments, the first magnification is 0.02c to 0.1c.

In some embodiments, the first magnification is 0.04c to 0.08c.

It should be noted that: the magnitude of the charge-discharge current is generally represented by a charge-discharge rate, and the letter 'C' represents the charge-discharge rate of the battery. The charge-discharge rate is a current value required for discharging the rated capacity of the battery for a prescribed time, and is equal to a multiple of the rated capacity of the battery in the data value, and is generally indicated by the letter C. For example: for a 24AH cell, the discharge current at 2C was 48a and the discharge voltage at 0.5C was 12A.

The specific value of 1C varies from battery system to battery system, and in general, the charge/discharge rate=charge/discharge current/rated capacity, and for example, when a battery having a rated capacity of 100Ah is discharged at 20A, the discharge rate is 0.2C.

In the foregoing "0.02 c-0.1 c", specific values include the minimum value and the maximum value of the range, and each value between the minimum value and the maximum value, and specific examples include, but are not limited to, the point values and the following point values in the embodiments: 0.02C, 0.03C, 0.04C, 0.05C, 0.06C, 0.07C, 0.08C, 0.09C, 0.1C; or a range of any two values.

In some embodiments, the second magnification is 0.33c to 1c.

In the foregoing "0.33 c-1 c", specific values include the minimum value and the maximum value of the range, and each value between the minimum value and the maximum value, and specific examples include, but are not limited to, the point values in the embodiments and the following point values: 0.33C, 0.4C, 0.45C, 0.5C, 0.55C, 0.6C, 0.65C, 0.7C, 0.75C, 0.8C, 0.85C, 0.9C, 0.95C, 1C; or a range of any two values.

In some of these embodiments, the first state of charge is less than or equal to 2% SOC.

In some of these embodiments, the first state of charge is: 1% SOC to 2% SOC.

In some of these embodiments, the second state of charge is less than or equal to 25% SOC.

In some of these embodiments, the first state of charge is 15% SOC to 25% SOC.

In some of these embodiments, the second state of charge is less than or equal to 20% SOC.

In some embodiments, the second state of charge is 15% SOC to 20% SOC.

In some of these embodiments, the predetermined state of charge is greater than or equal to 60% SOC.

In the above "1% SOC to 2% SOC", specific values include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, the point values in the embodiments and the following point values: 1% SOC, 1.1% SOC, 1.2% SOC, 1.3% SOC, 1.4% SOC, 1.5% SOC, 1.6% SOC, 1.7% SOC, 1.8% SOC, 1.9% SOC, 2% SOC; or a range of any two values.

In the above-mentioned "15% SOC to 25% SOC", specific values include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, the point values and the following point values ：15% SOC、15.5% SOC、16% SOC、15.5% SOC、17% SOC、17.5% SOC、18% SOC、18.5% SOC、19% SOC、19.5% SOC、20% SOC、20.5% SOC、21% SOC、21.5% SOC、22% SOC、22.5% SOC、23% SOC、23.5% SOC、24% SOC、24.5% SOC、25% SOC; or the range composed of any two values in the embodiment.

In some of these embodiments, the secondary formation process is performed as follows:

and (3) charging the battery subjected to secondary liquid injection to a preset charge state at a constant current of 0.33-1 ℃.

In some of these embodiments, the predetermined state of charge is: 60% SOC to 70% SOC.

In some embodiments, the temperature of the primary chemical conversion treatment is 25 ℃ to 45 ℃.

In some of these embodiments, the primary formation process is performed in a negative pressure environment.

It can be understood that: the relative pressure is the difference between the actual pressure and the atmospheric pressure, and can be directly tested by a pressure gauge.

After the step of one injection and before the step of one formation treatment, the method further comprises the following steps:

And standing the battery after primary liquid injection at 20-30 ℃ for 1-5 min. Further, the standing step is carried out under negative pressure, and the relative pressure of the negative pressure environment is minus 20Kpa to minus 0.2 Kpa.

After the step of constant current charging to the first state of charge at the first rate and before the step of constant current charging at the second rate, further comprising the steps of:

And standing the battery charged to the first charge state at the first multiplying power constant current at 20-30 ℃ for 3-10 min. Further, the standing step is carried out under negative pressure, and the relative pressure of the negative pressure environment is minus 20Kpa to minus 0.2 Kpa.

In some embodiments, after the step of primary forming treatment and before the step of secondary injection, the method further comprises the steps of:

And standing the battery subjected to the pre-formation at 20-30 ℃ for 1 min-5 min. Further, the standing step is performed under negative pressure.

In some embodiments, the mass ratio of the electrolyte used in the primary injection treatment is 80% -90% based on the total mass of the electrolyte used in the primary injection treatment and the electrolyte used in the secondary injection treatment.

In the foregoing "80% -90%", specific values include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, the point values in the embodiments and the following point values: 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%; or a range of any two values.

In some embodiments, the drying process is at a temperature of 95 ℃ to 115 ℃. Further, the temperature of the battery after the drying treatment is 95-115 ℃.

The drying temperature is further controlled, on one hand, moisture in the battery is fully volatilized, on the other hand, the battery can keep certain residual heat after drying, and when the electrolyte is directly injected, the residual heat can promote the infiltration of the electrolyte to the polar plate, so that the subsequent formation is facilitated.

In some embodiments, the method further comprises, after the step of secondary forming, a step of aging the secondary formed battery.

In some of these embodiments, the aging treatment is carried out at a temperature of 45 ℃ + -5deg.C for a time of 48 h + -2 h.

It is understood that the components of the electrolytes used for the primary injection and the secondary injection may be the same or different, and electrolytes commonly used in the art for secondary batteries may be used.

The electrolyte for secondary batteries commonly used in the art will be briefly described herein, including but not limited to the following.

The electrolyte includes an electrolyte salt and a solvent.

In some embodiments, the electrolyte salt may be selected from electrolyte salts commonly used in the art, such as lithium ion electrolyte salts.

As examples, lithium ion electrolyte salts include, but are not limited to: one or more of lithium hexafluorophosphate (LiPF ₆), lithium tetrafluoroborate (LiBF ₄), lithium perchlorate (LiClO ₄), lithium hexafluoroarsenate (LiAsF ₆), lithium bis-fluoro-sulfonimide (LiFSI), lithium bis-trifluoro-methanesulfonimide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluoro-oxalato-borate (lidaob), lithium difluoro-oxalato-borate (LiBOB), lithium difluoro-phosphate (LiPO ₂F₂), lithium difluoro-oxalato-phosphate (LiDFOP) and lithium tetrafluorooxalato-phosphate (LiTFOP).

In some embodiments, the solvent may be selected from one or more of fluoroethylene carbonate (FEC), ethylene Carbonate (EC), propylene Carbonate (PC), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl Propyl Carbonate (MPC), ethylene Propyl Carbonate (EPC), butylene Carbonate (BC), methyl Formate (MF), methyl Acetate (MA), ethyl Acetate (EA), propyl Acetate (PA), methyl Propionate (MP), ethyl Propionate (EP), propyl Propionate (PP), methyl Butyrate (MB), ethyl Butyrate (EB), 1, 4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), methyl ethyl sulfone (EMS), and diethyl sulfone (ESE).

In some embodiments, the concentration of electrolyte salt in the electrolyte is typically 0.5mol/L to 15mol/L.

In some embodiments, the electrolyte further optionally includes an additive. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives capable of improving certain properties of the battery, such as additives that improve the overcharge performance of the battery, additives that improve the high or low temperature performance of the battery, and the like.

In some embodiments, the electrolyte used in the single shot process contains a film former.

The film former may be a film former commonly used in the art including, but not limited to: at least one of VC (vinylene carbonate) and FEC (fluoroethylene carbonate).

It can be understood that the battery without liquid injection after the drying treatment comprises a battery component and a shell for wrapping the battery component, wherein the battery component comprises a positive plate, a negative plate and a diaphragm arranged between the positive plate and the negative plate. Further, the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly through a lamination process.

In some of these embodiments, the electrolyte is impregnated between the electrode assemblies.

The positive plate, the negative plate and the diaphragm can be common positive plates, negative plates and diaphragms embodied by various secondary batteries in the field, and the common positive plates, negative plates and diaphragms are described in the following, but are not limited to the following.

The negative electrode sheet comprises a current collector and a negative electrode active layer arranged on the surface of the current collector.

The current collector in the negative plate has two surfaces opposite in the thickness direction thereof, and the negative active layer is provided on either one or both of the two opposite surfaces of the current collector; further, a negative electrode active layer is provided on opposite surfaces of the current collector.

In some of these embodiments, the composition of the negative active layer of the negative electrode sheet includes a negative active material.

In some of these embodiments, the silicon negative electrode material comprises at least one of a silicon oxygen negative electrode material and a silicon carbon negative electrode material.

It is understood that the silicon carbon negative electrode material and the silicon oxygen negative electrode material may be specifically selected from various common silicon carbon negative electrode materials and silicon oxygen negative electrode materials in the art, and the common silicon carbon negative electrode materials and silicon oxygen negative electrode materials are described herein, but are not limited to the following.

Silicon-carbon negative electrode material: refers to a composite of silicon and carbon, the carbon employed includes, but is not limited to: at least one of graphite, MCMB, carbon black, carbon nanotubes, graphene; further, in the silicon carbon anode material, the mass ratio of silicon to carbon may be any ratio.

In some embodiments, the silicon-carbon negative electrode materials are mainly classified into a cladding type, an embedded type, and a molecular contact type according to a compounding manner, and classified into a particle type and a film type according to a morphology, and classified into a silicon-carbon binary compounding and a silicon-carbon multi-component compounding according to the number of silicon-carbon species.

The preparation process of the silicon-carbon composite material comprises a ball milling method, a high-temperature cracking method, a chemical vapor deposition method, a sputtering deposition method, an evaporation method and the like.

Silicon oxygen cathode material: the molecular formula is SiOx, x is an arbitrary value of 0-2. Non-limiting examples include: silica and silicon dioxide.

The carbon negative electrode material may be a carbon negative electrode material commonly used in the art, including but not limited to: at least one of mesophase carbon microspheres, natural graphite, artificial graphite, graphene, glassy carbon, carbon nanotubes, carbon fibers, hard carbon and soft carbon.

In some of these embodiments, the negative active layer of the negative electrode sheet further comprises a conductive agent and a binder.

In some embodiments, the mass ratio of the anode active material in the anode active layer is not 70% -99%.

In some embodiments, the mass ratio of the conductive agent in the anode active layer is selected from 1% -5%.

In some embodiments, the mass ratio of the binder in the negative electrode active layer is selected from 1% -5%.

The conductive agent may be a conductive material commonly used in the art, including but not limited to: at least one of graphite, carbon nanotubes, nanofibers, carbon black, and graphene. Specifically, the conductive material is at least one selected from SP, KS-6, acetylene black, ketjen black ECP with branched structure, SFG-6, vapor grown carbon fiber VGCF, carbon nanotube CNTs, graphene and composite conductive agent thereof.

The binder may be at least one binder commonly used in the art, and may be selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, hydrogenated nitrile rubber, styrene Butadiene Rubber (SBR), polyacrylic acid (PAA), sodium Polyacrylate (PAAs), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium Alginate (SA), polymethacrylic acid (PMAA), carboxymethyl chitosan (CMCS), and fluoroacrylate resin.

In some of these embodiments, the current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum foil may be used. The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material base layer. The composite current collector may be formed by forming a metal material on a polymeric material substrate.

In some of these embodiments, the metallic material comprises at least one of aluminum, aluminum alloy, nickel alloy, titanium alloy, silver, and silver alloy.

In some of these embodiments, the polymeric material substrate comprises at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE).

In some of these embodiments, the positive electrode sheet includes a current collector and a positive electrode active layer disposed on the surface of the current collector.

In the technical scheme of the application, the two opposite surfaces of the current collector in the thickness direction of the positive plate are provided with the positive electrode active layer.

In any embodiment of the present application, the current collector in the positive electrode sheet may be a metal foil or a composite current collector. For example, as the metal foil, aluminum foil may be used. The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material base layer. The composite current collector may be formed by forming a metal material on a polymeric material substrate.

The composition of the positive electrode active layer includes a positive electrode active material.

The above-mentioned positive electrode active material may be a common positive electrode active material in the present application, for example, a lithium ion positive electrode active material or a sodium ion positive electrode active material.

Further, as an example, the lithium ion active material may include at least one of the following materials: olivine structured lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material may be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of the lithium transition metal oxide may include, but are not limited to, at least one of lithium cobalt oxide (e.g., liCoO ₂), lithium nickel oxide (e.g., liNiO ₂), lithium manganese oxide (e.g., liMnO ₂、LiMn₂O₄), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., liNi _1/3Co_1/3Mn_1/3O₂ (may also be abbreviated as NCM 333), liNi _0.5Co_0.2Mn_0.3O₂ (may also be abbreviated as NCM 523), liNi _0.5Co_0.25Mn_0.25O₂ (may also be abbreviated as NCM 211), liNi _0.6Co_0.2Mn_0.2O₂ (may also be abbreviated as NCM 622), liNi _0.8Co_0.1Mn_0.1O₂ (may also be abbreviated as NCM 811), lithium nickel cobalt aluminum oxide (e.g., liNi _0.85Co_0.15Al_0.05O₂), and modified compounds thereof, etc., examples of the lithium-containing phosphate of the olivine structure may include, but are not limited to, at least one of lithium iron phosphate (e.g., liFePO ₄ (may also be abbreviated as LFP)) lithium manganese phosphate (e.g., liMnPO ₄), lithium manganese iron phosphate.

In any embodiment of the present application, the lithium ion active material has the formula: liFe _xMn_(1-x)PO₄, x is any number from 0 to 1.

It can be appreciated that when x takes 0, liFe _xMn_(1-x)PO₄ is LiMnPO ₄ lithium manganese phosphate, and when x takes 1, liFePO ₄ is LiFePO ₄ lithium iron phosphate (LFP).

It should be noted that, the lithium content in the above-mentioned example positive electrode material refers to the content of the positive electrode material when not in use, the battery will repeatedly act as electricity during the use process, the Li in the positive electrode active material will change during the charge and discharge process, i.e. the molar index of the Li in the positive electrode active material in the battery product will not be kept at 1 all the time, and will change; further, the variation range may be (0 to 1.2).

For example, liFe _xMn_(1-x)PO₄ may be further represented as Li _yFe_xMn_(1-x)PO₄, with y being 0 to 1.1.

For example, for ternary material Li _y(Ni_aCo_bMn_c)_1-dM_dO_2-xA_x, y is 0.2-1.2, a+b+c=1, 0.ltoreq.d.ltoreq.1, 0.ltoreq.x <2; m is one or more of Zr, sr, B, ti, mg, sn and Al, A is one or more of S, N, F, cl, br and I.

The battery can be accompanied with the deintercalation and consumption of Li in the charging and discharging process, the molar contents of Li are different when the battery is discharged to different states, and the limitation on y comprises the molar contents of Li in different charging and discharging states of the battery; further, the battery voltage is typically between 2-5V.

Similarly, in the present application, the content of oxygen (O) is only a theoretical state value, and the molar content of oxygen changes due to lattice oxygen release, so that the actual O content floats. The content of O may be measured by molar content, but is not limited thereto.

As an example, the sodium ion active material may include at least one of the following materials: at least one of sodium transition metal oxide, polyanion compound and Prussian blue compound. However, the present application is not limited to these materials, and other conventionally known materials that can be used as a positive electrode active material of a sodium ion battery may be used.

As an alternative embodiment of the present application, the transition metal in the sodium transition metal oxide includes at least one of Mn, fe, ni, co, cr, cu, ti, zn, V, zr and Ce. The sodium transition metal oxide is Na _xMO₂, for example, wherein M at least comprises one or more of Ti, V, mn, co, ni, fe, cr and Cu, and x is more than 0 and less than or equal to 1.

As an alternative embodiment of the present application, the polyanion compound may be a compound having sodium ion, transition metal ion and tetrahedral type (YO ₄)^n- anion unit, wherein the transition metal includes at least one of Mn, fe, ni, co, cr, cu, ti, zn, V, zr and Ce, Y includes at least one of P, S and Si, and n represents (YO ₄)^n- valence state).

The polyanionic compound may also be a compound having sodium ion, transition metal ion, tetrahedral type (YO ₄)^n- anion unit and halogen anion, transition metal includes at least one of Mn, fe, ni, co, cr, cu, ti, zn, V, zr and Ce, Y includes at least one of P, S and Si, n represents (YO ₄)^n- valence state; halogen may be at least one of F, cl and Br).

The polyanionic compound may also be a compound of the type having sodium ions, tetrahedral (YO ₄)^n- anion units, polyhedral units (ZO _y)^m+ and optionally halogen anions. Y comprises at least one of P, S and Si, n represents (YO ₄)^n- valence; Z represents transition metal, comprises at least one of Mn, fe, ni, co, cr, cu, ti, zn, V, zr and Ce), m represents (ZO _y)^m+ valence; halogen may be at least one of F, cl and Br).

The polyanion compound is at least one of NaFePO ₄、Na₃V₂(PO₄)₃ (sodium vanadium phosphate, NVP for short), na ₄Fe₃(PO₄)₂(P₂O₇)、NaM'PO₄ F (M' is one or more of V, fe, mn and Ni) and Na ₃(VO_y)₂(PO₄)₂F_3-2y (y is more than or equal to 0 and less than or equal to 1).

Prussian blue compounds may be a class of compounds having sodium ions, transition metal ions, and cyanide ions (CN ^-). The transition metal includes at least one of Mn, fe, ni, co, cr, cu, ti, zn, V, zr and Ce. Prussian blue compounds are, for example, na _aMe_bMe'_c(CN)₆, where Me and Me' each independently include at least one of Ni, cu, fe, mn, co and Zn, 0 < a.ltoreq.2, 0 < b < 1,0 < c < 1.

The weight ratio of the positive electrode active material in the positive electrode active layer is 80% -100% based on the total weight of the positive electrode active layer.

In any embodiment of the present application, the components of the positive electrode active layer further include a positive electrode conductive agent and a positive electrode binder.

The positive electrode conductive agent may be a conductive agent commonly used in the art, including but not limited to: at least one of graphite, carbon nanotubes, nanofibers, carbon black, and graphene. Specifically, the conductive material is at least one selected from SP, KS-6, acetylene black, ketjen black ECP with branched structure, SFG-6, vapor grown carbon fiber VGCF, carbon nanotube CNTs, graphene and composite conductive agent thereof.

The weight ratio of the positive electrode conductive agent in the positive electrode active layer is 0-20wt% based on the total weight of the positive electrode active layer.

In any embodiment of the present application, the binder of the positive electrode binder may be at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, hydrogenated nitrile rubber, styrene Butadiene Rubber (SBR), polyacrylic acid (PAA), sodium Polyacrylate (PAAs), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium Alginate (SA), polymethacrylic acid (PMAA), carboxymethyl chitosan (CMCS), and a fluoroacrylate resin.

The weight ratio of the positive electrode binder in the positive electrode active layer is 0 to 30wt% based on the total weight of the positive electrode active layer.

In some of these embodiments, the positive plate has a compacted density of 3.0g/cm ³~3.7g/cm³, optionally 3.4g/cm ³~3.6g/cm³. The calculation formula of the compaction density is as follows:

Compacted density = coated area density/(post-extrusion pole piece thickness-current collector thickness).

The type of the separator is not particularly limited, and any known porous separator having good chemical stability and mechanical stability can be used.

In some embodiments, the material of the isolating film may be at least one selected from glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multilayer composite film, and is not particularly limited. When the separator is a multilayer composite film, the materials of the respective layers may be the same or different, and are not particularly limited.

The thickness of the diaphragm is controlled to be 2-15 mu m; optionally, the thickness of the diaphragm is controlled to be 2-13 μm.

In some of these embodiments, the positive or negative electrode sheet may be prepared by: dispersing the positive electrode active layer or the negative electrode active component in a solvent to form slurry; and (3) coating the slurry on a current collector, and drying, cold pressing and the like to obtain the pole piece.

Further, solvents include, but are not limited to: n-methylpyrrolidone or water.

The components of the positive electrode active layer or the negative electrode active layer are referred to as above, and are not described in detail herein.

In some embodiments, the slurry has a solids content of 40 wt-80 wt%, and the viscosity at room temperature is adjusted to 5000 mPa-25000 mPa-s.

Methods of such coating include, but are not limited to, print coating, blade coating, spin coating, or ink jet coating. And (3) coating the slurry on a current collector, and drying, cold pressing and other procedures to obtain the coating.

The application further provides a battery which is manufactured by the manufacturing method of the battery.

In some embodiments, the battery is a secondary battery; specifically, the battery is a lithium ion battery.

The shape of the battery of the present application is not particularly limited, and may be square or any other shape. For example, fig. 2 is a square-structured battery cell 4 as an example.

In some embodiments, referring to fig. 3, the housing may include a shell 41 and a cover plate 43. The housing 41 may include a bottom plate and a side plate connected to the bottom plate, where the bottom plate and the side plate enclose a receiving chamber. The housing 41 has an opening communicating with the accommodation chamber, and the cover plate 43 can be provided to cover the opening to close the accommodation chamber.

The positive electrode sheet, the negative electrode sheet, and the separator may be formed into the electrode assembly 42 through a winding process or a lamination process. The electrode assembly 42 is packaged in the receiving chamber. The electrolyte is impregnated in the electrode assembly 42. The number of electrode assemblies 42 included in the battery cell 4 may be one or more, and may be adjusted according to the need.

The battery comprises one or more battery cells 4.

The battery may be a battery module or a battery pack; the battery module or the battery pack includes at least one battery cell. The number of battery cells 4 included in the battery module may be one or more, and one skilled in the art may select an appropriate number according to the application and capacity of the battery module.

Fig. 4 and 5 are battery packs 1 as an example. The battery pack 1 includes a battery case and one or more battery cells 4 provided in the battery case. The battery box comprises an upper box body 2 and a lower box body 3, wherein the upper box body 2 can be covered on the lower box body 3, and a closed space for the battery cells 4 is formed.

The plurality of battery cells 4 may be arranged in the battery box in any manner.

The application also provides an electric device which comprises the battery.

Further, in the above-mentioned power consumption device, the battery may exist in the form of a battery cell or may exist in the form of a battery pack further assembled.

The battery or the battery pack assembled by the battery can be used as a power source of an electric device and also can be used as an energy storage unit of the electric device.

The above-mentioned electric device may be, but is not limited to, a mobile device, an electric vehicle, an electric train, a ship, a satellite, an energy storage system, or the like.

Mobile devices include, but are not limited to: cell phones, notebook computers, etc.; electric vehicles include, but are not limited to: pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, and the like.

Fig. 6 is an electric device 5 as an example. The electric device 5 is a pure electric vehicle, a hybrid electric vehicle or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of the battery of the power consumer 5, a battery pack may be used.

As another example, the power consumption device may be a mobile phone, a tablet computer, a notebook computer, or the like. The device is generally required to be light and thin, and a battery can be used as a power source.

The application will be described in connection with specific embodiments, but the application is not limited thereto, and it will be appreciated that the appended claims outline the scope of the application, and those skilled in the art, guided by the inventive concept, will appreciate that certain changes made to the embodiments of the application will be covered by the spirit and scope of the appended claims.

The following are specific examples.

Example 1

(1) The preparation of the lithium ion battery comprises the following steps:

And winding the positive plate, the diaphragm and the negative plate to obtain an electrode assembly, placing the electrode assembly in a packaging shell, leading out a tab from the electrode assembly, and assembling to obtain the NCM811 lithium ion battery with the theoretical capacity of 60Ah, wherein the charging multiplying power of the battery is 1C=60 Ah.

The preparation method of the negative plate comprises the following steps:

Graphite, conductive carbon super P, thickener sodium carboxymethyl cellulose and binder styrene-butadiene rubber are mixed according to the mass ratio of 96.5:0.7:1.2:1.6, then adding water, mixing and stirring to obtain a cathode slurry with the solid content of 50wt%, coating the cathode slurry on a cathode current collector with the thickness of 6 mu m, coating the cathode current collector with the unit mass of 0.1636g/1540.25mm ², drying, and cold pressing according to the compaction of 1.63g/cm ³ to obtain a cathode plate with the thickness of 0.1363 mm.

The preparation steps of the positive plate are as follows:

NCM811, conductive carbon super P, binder polyvinylidene fluoride in a mass ratio of 96.5:2.3:1.2, adding N-methyl pyrrolidone, mixing and stirring to obtain positive electrode slurry with the solid content of 50wt%, coating the positive electrode slurry on a positive electrode current collector with the thickness of 13 mu m, coating the positive electrode current collector with the unit mass of 0.280g/1540.25mm ², drying, and cold pressing according to the compaction of 3.4g/cm ³ to obtain a positive electrode sheet with the thickness of 0.1190 mm.

The isolating film is prepared by coating PE (polyethylene) film with 7 μm thickness on two side surfaces of the film with ceramic layers with 1 μm thickness respectively, wherein the ceramic layers are formed by coating and drying ceramic slurry with 40wt% of solid content, and the preparation steps of the ceramic slurry are as follows:

boehmite, styrene-butadiene rubber as a binder and a thickener according to the mass ratio of 96:2:2 mixing and adding water, mixing and stirring to obtain ceramic slurry with solid content of 40 wt%.

(2) Placing the NCM811 lithium ion battery assembled in the step (1) in a blocking furnace with the temperature of 100 ℃ for drying treatment, injecting liquid once to the battery within 2 hours after the weight loss rate of the battery reaches the standard, immediately placing the battery into negative pressure formation equipment with the relative pressure of-20 Kpa and the temperature of 25 ℃, standing for 1min, performing primary formation treatment, namely charging to a first charge state (2% SOC) with a constant current of a first multiplying power (0.1C), standing for 5min, charging to a second charge state (20% SOC) with a constant current of a second multiplying power (0.5C), standing for 5min, discharging vacuum, and ending the primary formation treatment; then continuously injecting the rest 15% electrolyte, and performing secondary formation treatment: charging to a preset charge state (70% SOC) of the battery capacity at a charge rate of 0.5C, and standing and aging the battery in a high-temperature furnace at 45 ℃ for 48 hours to obtain the battery.

In the above preparation process, the time elapsed from the start of the first injection to the start of the high temperature aging treatment was recorded and denoted as H, and specific results are shown in table 1.

The electrolyte used for the primary injection and the secondary injection is prepared as follows:

the electrolyte comprises the following components in percentage by mass: 1:1:13:70, a film forming additive vinylene carbonate VC, a film forming additive ethylene sulfate DTD, a solvent ethylene carbonate EC and a solvent dimethyl carbonate DMC.

(3) And (3) testing:

1. the battery after the aging treatment is placed in room temperature (25 ℃), and the self-discharge change value T in 48 hours at room temperature is tested and recorded, wherein the specific steps are as follows:

Standing the battery after the aging treatment in room temperature (25 ℃) for 12 hours, and recording the voltage OCV1 of the battery at the moment; then, after the mixture is continuously placed at room temperature for 48 hours, OCV2 is recorded; the voltage unit is mV; t= (OCV 1-OCV 2)/48; t is in mV/h. The specific results are shown in Table 1.

2. Interface condition of battery negative plate:

and carrying out full charge treatment on the battery subjected to the high-temperature treatment, wherein the specific steps are as follows:

The battery after the high temperature treatment is placed in a charge-discharge machine device, the temperature is set at room temperature (25 ℃), after the battery temperature is reduced to room temperature, the battery is firstly discharged to 2.8V at the multiplying power of 0.5C, the battery is placed for 5min, then the battery is charged to 4.25V at the multiplying power of 0.5C, and then the battery is charged at a constant voltage of 4.25V until the multiplying power is reduced to 0.05C.

Then, the negative electrode plate is disassembled, the interface condition of the negative electrode plate is confirmed, whether the analysis and the appearance of black spots are observed, and specific results are shown in Table 1.

3. And (3) testing the yield:

repeating the steps (1) - (3) to obtain 100 batches of batteries, judging the batteries as good products if no analysis and black spots appear on the interface of the negative plate and the self-discharge change value T is less than or equal to 0.02mV/h, and calculating the yield:

yield = number of good/total number of cells ×%

The specific results are shown in Table 1.

Examples 2 to 8

Examples 2 to 8 are basically the same as example 1, except that: in the step (2), at least one parameter of the first multiplying power, the second multiplying power, the first charge state or the second charge state is controlled differently from the embodiment 1, and specific parameters and test results are shown in table 1.

Other procedure conditions were the same as in example 1.

Comparative example 1

Comparative example 1 is substantially the same as example 1 except that: the specific steps of the step (2) are as follows:

(2): placing the NCM811 lithium ion battery assembled in the step (1) in a blocking furnace with the temperature of 100 ℃ for drying treatment, injecting liquid once to the battery within 2 hours after the weight loss rate of the battery reaches the standard, immediately placing the battery into negative pressure formation equipment with the relative pressure of-20 Kpa and the temperature of 25 ℃, standing for 1min, performing primary formation treatment, namely charging to a first charge state (2% SOC) by constant current with a first multiplying power (0.1C), standing for 5min, charging to a second charge state (70% SOC) by constant current with a second multiplying power (0.5C), standing for 5min, discharging vacuum, and ending the primary formation treatment; and then continuously injecting the rest 15% electrolyte, and then placing the battery in a high-temperature furnace at 45 ℃ for standing and aging treatment for 48 hours to obtain the battery.

Other steps are the same as in example 1, and specific parameters and test results are shown in Table 1.

Comparative example 2

Comparative example 2 is substantially the same as example 1 except that: the step (2) comprises the following steps:

(2) Placing the NCM811 lithium ion battery assembled in the step (1) in a blocking furnace with the temperature of 100 ℃ for drying treatment, injecting liquid once to the battery within 2 hours after the weight loss rate of the battery reaches the standard, immediately placing the battery into negative pressure formation equipment with the relative pressure of-20 Kpa and the temperature of 25 ℃, standing for 1min, performing primary formation treatment, namely charging to a first charge state (2% SOC) by constant current with a first multiplying power (0.1C), standing for 5min, charging to a second charge state (20% SOC) by constant current with a second multiplying power (0.5C), standing for 5min, discharging vacuum, and ending the primary formation treatment; and then continuously injecting the rest 15% electrolyte, and then placing the battery in a high-temperature furnace at 45 ℃ for standing and aging treatment for 48 hours to obtain the battery.

Comparative example 3

Comparative example 3 is substantially the same as example 1 except that: the step (2) comprises the following steps:

(2) Placing the NCM811 lithium ion battery assembled in the step (1) in a blocking furnace with the temperature of 100 ℃ for drying treatment, injecting liquid once to the battery within 2 hours after the weight loss rate of the battery reaches the standard, placing the battery in a high-temperature furnace with the temperature of 45 ℃ for high-temperature standing treatment for 10 hours, immediately placing the battery in negative pressure formation equipment with the relative pressure of-20 Kpa and the temperature of 25 ℃, standing for 1 minute, performing primary formation treatment, namely charging to a first charge state (2% SOC) by constant current with a first multiplying power (0.1C), then charging to a second charge state (70% SOC) by constant current with a second multiplying power (0.5C) after standing for 5 minutes, discharging vacuum after standing for 5 minutes, and ending the primary formation treatment; and then continuously injecting the rest 15% electrolyte, and then placing the battery in a high-temperature furnace at 45 ℃ for standing and aging treatment for 48 hours to obtain the battery.

Comparative example 4

Comparative example 4 is substantially the same as example 1 except that: the step (2) comprises the following steps:

(2) Placing the NCM811 lithium ion battery assembled in the step (1) in a blocking furnace with the temperature of 100 ℃ for drying treatment, injecting liquid once to the battery within 2 hours after the weight loss rate of the battery reaches the standard, immediately placing the battery into negative pressure formation equipment with the relative pressure of-20 Kpa and the temperature of 25 ℃, standing for 1min, performing primary formation treatment, namely charging to a first charge state (2% SOC) by constant current with a first multiplying power (0.5C), standing for 5min, charging to a second charge state (20% SOC) by constant current with a second multiplying power (0.1C), standing for 5min, discharging vacuum, and ending the primary formation treatment; then continuously injecting the rest 15% electrolyte, and performing secondary formation treatment: charging to a preset charge state (70% SOC) of the battery capacity at a charge rate of 0.5C, and standing and aging the battery in a high-temperature furnace at 45 ℃ for 48 hours to obtain the battery.

The parameters and test results of each example and comparative example are shown in Table 1. Wherein the first state of charge is noted as X% and the second state of charge is noted as Y%.

TABLE 1

Note that: "/" indicates that no change step is performed or that no change parameter is present.

Analysis of table 1 data: the data of comparative examples 1 to 8 and comparative examples 1 to 4 show that: by adopting the technical scheme of the application, the battery with perfect performance can be prepared even without carrying out additional high-temperature standing step after one-time liquid injection, the preparation time is shortened, and the preparation efficiency is improved.

Among them, comparative analysis example 1 and comparative example 3 revealed that: after liquid injection, the electrolyte is directly formed into a higher SOC state, black spots and lithium precipitation are possibly caused by insufficient electrolyte infiltration, and a longer high-temperature standing time is required to be additionally added after liquid injection to ensure that the fully charged interface after the formation into the high SOC is good (such as comparative example 3), if the subsequent high SOC charge is canceled, the black spots and the lithium precipitation are not only caused on the fully charged negative electrode interface, but also the voltage change in the detection unit time is large due to the large slope area of the charging curve corresponding to the 20% SOC stage, so that the screening of samples with poor discharge (such as comparative example 2) is not facilitated; in comparative example 4, the charging with a larger multiplying power is performed at the beginning of the formation, which results in insufficient infiltration and serious adverse phenomena at the interface of the pole piece.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. The scope of the application is therefore intended to be covered by the appended claims, and the description and drawings may be interpreted in accordance with the contents of the claims.

Claims

1. A method of making a battery comprising the steps of:

Wherein, the primary formation treatment comprises the following steps:

The battery after the primary liquid injection is charged to a first charge state with a constant current of a first multiplying power, and then is charged to a second charge state with a constant current of a second multiplying power;

Wherein the first magnification is less than the second magnification, the first state of charge is less than the second state of charge, and the second state of charge is less than the predetermined state of charge;

The second charge state is 15-19% of SOC.

2. The method of claim 1, wherein the first rate is 0.02c to 0.1c.

3. The method for manufacturing a battery according to claim 1, wherein the first rate is 0.04c to 0.08c.

4. The method for manufacturing a battery according to any one of claims 1 to 3, wherein the second rate is 0.33c to 1c.

5. The method for manufacturing a battery according to any one of claims 1 to 3, wherein the method satisfies at least one of the following conditions (1) to (2):

(1) The first state of charge is less than or equal to 2% SOC;

(2) The predetermined state of charge is greater than or equal to 60% SOC.

6. The method for manufacturing a battery according to any one of claim 1 to 3, wherein,

The first state of charge is: 1% SOC to 2% SOC.

7. A method of manufacturing a battery according to any one of claims 1 to 3, wherein the secondary formation treatment comprises the steps of:

8. The method for manufacturing a battery according to any one of claims 1 to 3, wherein the method satisfies at least one of the following conditions (1) to (2):

and standing the battery subjected to the pre-formation for 1-5 min at 20-30 ℃.

9. The method for manufacturing a battery according to any one of claims 1 to 3, wherein the method for manufacturing a battery satisfies at least one of the following conditions (1) to (2):

(1) The temperature of the primary formation treatment is 25-45 ℃;

10. The method of claim 9, wherein the relative pressure of the negative pressure environment is-20 Kpa to-0.2 Kpa.

11. The method for manufacturing a battery according to any one of claims 1 to 3, wherein the method for manufacturing a battery satisfies at least one of the following conditions (1) to (2):

12. The method for manufacturing a battery according to any one of claims 1 to 3, wherein the temperature of the drying treatment is 95 ℃ to 115 ℃.

13. The method for manufacturing a battery according to any one of claims 1 to 3, further comprising the step of aging the battery after the secondary formation treatment after the step of the secondary formation treatment.

14. The method for manufacturing a battery according to claim 13, wherein the aging treatment is performed at a temperature of 45 ℃ ± 5 ℃ for a time of 48h ± 2h.

15. A battery prepared by the method for preparing a battery according to any one of claims 1 to 14.

16. An electrical device comprising the battery of claim 15.