Chemical pre-lithiation reagent for sulfide solid-state battery as well as preparation method and application of chemical pre-lithiation reagent

Abstract

The invention provides a chemical pre-lithiation reagent for a sulfide solid-state battery as well as a preparation method and application of the chemical pre-lithiation reagent. The chemical pre-lithiation reagent comprises an aromatic compound, a lithium source, a solvent A and a solvent B, wherein the concentration of the aromatic compound in the chemical pre-lithiation reagent is 0.0009 mol / L-8. 5mol / L, the mass ratio of the lithium source to the aromatic compound is (1-10): (10-1), and the mass ratio of the solvent B to the solvent A is (1-10): (5-1); the polarity of the solvent A is 3-7; the polarity of the solvent B is less than 3. According to the pre-lithiation method, the purpose of regulating and controlling the pre-lithiation amount is achieved by preparing the specific pre-lithiation reagent and then soaking or wetting the silicon-based negative electrode piece, the purpose of pre-lithiation of the silicon-based negative electrode is accurately achieved, and the first coulombic efficiency and the energy density of the sulfide all-solid-state battery are improved. Meanwhile, the volume expansion of the silicon-based material is relieved to a certain extent, and the cycle life of the all-solid-state battery is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-state batteries and relates to a chemical pre-lithiation reagent for sulfide solid-state batteries and a preparation method and application thereof. Background Art

[0002] Among various types of all-solid-state batteries, sulfide all-solid-state batteries have become the most promising choice for electric vehicles due to their high ionic conductivity. At present, in order to pursue high-energy-density all-solid-state batteries in the industry, most lithium metal or silicon-based materials are used as negative electrodes. Lithium metal as the negative electrode of all-solid-state batteries has problems such as interface instability and growth of lithium dendrites. In contrast, silicon-based materials have the advantages of low cost, high energy density, good compatibility with sulfide solid electrolytes, and processability. However, compared with traditional graphite-based materials, silicon-based materials have larger initial irreversible capacity and lower cycle stability, which seriously affects the energy density and service life of the battery.

[0003] Pre-lithiation of silicon-based negative electrodes is the main way to alleviate the problems associated with silicon-based materials. However, the pre-lithiation reagents generally used for pre-lithiation require medium-polarity solvents to dissolve aromatic compounds and lithium metal, and sulfide solid electrolytes will react with polar solvents, resulting in an inevitable decrease in their ionic conductivity.

[0004] In this regard, how to solve the problems existing in the pre-lithiation process of silicon-based negative electrodes, realize the application of silicon-based materials in sulfide all-solid-state batteries, and improve the energy density of all-solid-state batteries are issues that need to be addressed. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a chemical pre-lithiation reagent for sulfide solid-state batteries, a preparation method thereof, and an application thereof. The present invention achieves the purpose of regulating the amount of pre-lithiation by configuring a specific pre-lithiation reagent and then soaking or wetting the silicon-based negative electrode plate, accurately achieving the purpose of pre-lithiation of the silicon-based negative electrode, and improving the first coulombic efficiency and energy density of the sulfide all-solid-state battery. At the same time, the volume expansion of the silicon-based material is alleviated to a certain extent, and the cycle life of the all-solid-state battery is improved.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a chemical pre-lithiation reagent, which comprises an aromatic compound, a lithium source, a solvent A and a solvent B; wherein the concentration of the aromatic compound in the chemical pre-lithiation reagent is 0.0009 mol / L-8.5 mol / L, the mass ratio of the lithium source to the aromatic compound is (1-10):(10-1), and the mass ratio of solvent B to solvent A is (1-10):(5-1); the polarity of solvent A is 3-7; and the polarity of solvent B is <3.

[0008] As a preferred embodiment of the present invention, the aromatic compound includes any one or a combination of at least two of biphenyl, naphthalene, dimethyl biphenyl or tetramethyl biphenyl.

[0009] As a preferred embodiment of the present invention, the lithium source includes any one of metallic lithium, lithium alloy or lithium foil, or a combination of at least two of them.

[0010] As a preferred embodiment of the present invention, the solvent A includes any one of 1,2-dimethoxyethane, tetrahydrofuran or 2-methyltetrahydrofuran, or a combination of at least two thereof.

[0011] As a preferred embodiment of the present invention, the solvent B includes any one of heptane, xylene, anisole, petroleum ether or butyl butyrate, or a combination of at least two thereof.

[0012] In a second aspect, the present invention provides a method for preparing the aforementioned chemical pre-lithiation reagent, the preparation method comprising: adding a lithium source to a mixture of an aromatic compound and a solvent A, stirring and mixing, and then adding a solvent B to obtain a chemical pre-lithiation reagent.

[0013] As a preferred embodiment of the present invention, the concentration of the aromatic compound in the mixture of the aromatic compound and the solvent A is 0.01 mol / L-10 mol / L, preferably 1 mol / L.

[0014] As a preferred embodiment of the present invention, the stirring rate of the stirring and mixing is 100 r / min-8000 r / min, preferably 500 r / min-2000 r / min.

[0015] In a third aspect, the present invention provides a pre-lithiated negative electrode plate, wherein the negative electrode plate is obtained by treating with the aforementioned chemical pre-lithiation reagent.

[0016] As a preferred embodiment of the present invention, the negative electrode plate includes any one of a silicon-based negative electrode plate, a graphite negative electrode plate or an alloy negative electrode plate.

[0017] In a fourth aspect, the present invention provides a method for preparing the aforementioned negative electrode plate, the preparation method comprising: soaking the negative electrode plate in a chemical pre-lithiation reagent and then drying;

[0018] Alternatively, a chemical pre-lithiation agent is applied to the negative electrode plate and then dried.

[0019] As a preferred embodiment of the present invention, the soaking time is 1 min-600 min.

[0020] In a fifth aspect, the present invention provides a sulfide solid-state battery, wherein the negative electrode used in the sulfide solid-state battery is the aforementioned pre-lithiated negative electrode plate.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention achieves the purpose of regulating the amount of pre-lithiation by configuring a specific pre-lithiation reagent and controlling the dosage ratio of each component, and then immersing or wetting the silicon-based negative electrode plate, thereby accurately achieving the purpose of pre-lithiation of the silicon-based negative electrode, reducing the reaction of the sulfide solid electrolyte, and improving the first coulombic efficiency and energy density of the sulfide all-solid-state battery.

[0023] At the same time, it can alleviate the volume expansion of silicon-based materials to a certain extent and improve the cycle life of all-solid-state batteries. DETAILED DESCRIPTION

[0024] In order to better illustrate the present invention and facilitate understanding of the technical solution of the present invention, the present invention is further described in detail below. However, the following embodiments are only simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0025] In the first aspect, the specific implementation of the present invention provides a chemical pre-lithiation reagent, which includes an aromatic compound, a lithium source, a solvent A and a solvent B; wherein the concentration of the aromatic compound in the chemical pre-lithiation reagent is 0.0009mol / L-8.5mol / L, for example, 0.0009mol / L, 0.001mol / L, 0.005mol / L, 0.01mol / L, 0.05mol / L, 0.1mol / L, 0.5mol / L, 1mol / L, 2mol / L, 4mol / L, 6mol / L, 8mol / L or 8.5mol / L, etc., but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable; the mass ratio of the lithium source to the aromatic compound is (1-10):(10-1), for example 1:(10-1), 2:(10-1), 4:(10-1), 6:(10-1), 8:(10-1), 10:(10-1), (1-10):1, ( 1-10):2, (1-10):4, (1-10):6, (1-10):8 or (1-10):10, etc., but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable; the mass ratio of solvent B to solvent A is (1-10):(5-1), for example 1:(5-1), 2:(5-1), 4:(5-1), 6:(5-1), 8:(5-1), 10:(5-1), (1-10):5, (1-10):4, (1-10):3, (1-10):2 or (1-10):1, etc., but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable; the polarity of solvent A is 3-7, such as 3, 4, 5, 6 or 7, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable; the polarity of solvent B is <3, such as 2, 1.5, 1 or 0.5, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] In the present invention, "polarity" is mainly determined based on the dielectric constant of the organic solvent combined with the common organic solvent polarity table. Dielectric constant is an important indicator to measure the polarity of the solvent. Generally, polar solvents have a higher dielectric constant, while non-polar solvents have a lower dielectric constant. The polarity of the solvent can be preliminarily determined by measuring its dielectric constant. The dielectric constant of the solvent to be measured is determined according to the flat plate capacitor measurement method. The specific method is to use two parallel plates to form a capacitor, fill the liquid to be measured, and measure the change in capacitance to calculate the dielectric constant. The formula is as follows: εr = C / C0, where εr is the relative dielectric constant and C is the capacitance after filling the liquid. C0 is the capacitance in a vacuum.

[0027] According to the comparison between the calculated dielectric constant of the liquid to be tested and the dielectric constant of the solvent with known polarity, the range of its polarity can be preliminarily determined. For example, according to the polarity table of common organic solvents, the polarity of water is 10.2, which is 78.36F / m at 25°C. According to the polarity table of common organic solvents, the polarity of benzene and isobutyl alcohol is 3, the polarity of ethylene glycol is 6.9, and the polarity of dimethyl sulfoxide is 7.2. Then, the dielectric constants are measured, and the dielectric constant of the solvent to be tested is compared with the dielectric constants of the above-mentioned liquids to obtain the relative range of their polarity.

[0028] In the present invention, if the polarity of solvent A is too small, it will be difficult to dissolve the lithium source, and then it will be difficult to form a stable pre-lithiation reagent. If the polarity is too large, it will react with the sulfide solid electrolyte in the negative electrode during the pre-lithiation process, affecting the electrical properties of the negative electrode. If the polarity of solvent B is too large, it will also cause more side reactions with the sulfide solid electrolyte in the negative electrode during the pre-lithiation process, affecting the capacity of the negative electrode.

[0029] In the present invention, the dosage of solvent A and solvent B needs to be controlled within a reasonable range. The amount of solvent A added should not be too much, and the aromatic compound can be completely dissolved. If the amount of solvent A is too much, more side reactions will occur with the sulfide solid electrolyte, reducing the ionic conductivity of the sulfide solid electrolyte. If the amount is too little, the aromatic compound will not be completely dissolved, and the amount of chemical reagents formed will not reach the target amount, making it difficult to dissolve all lithium sources, resulting in waste of lithium sources and reduced lithium supplementation effect. The amount of solvent B is guaranteed to completely dissolve metallic lithium and aromatic compounds, and a saturated or nearly saturated solution can be configured, and it is ensured that the configured solution can completely soak a certain amount of pole pieces. The amount of solvent B accounts for a relatively high proportion in the entire solvent system, but it still needs to be controlled within a reasonable range. If the content of solvent B is too high, the concentration of the chemical pre-lithiation reagent will be greatly reduced, the lithium supplementation effect will be reduced, and the target amount of lithium supplementation will not be reached. If the content is too little, a small amount of pre-lithiation reagent will be formed, making it difficult to completely soak the target product, resulting in uneven pre-lithiation.

[0030] As a preferred embodiment of the present invention, the lithium source includes any one of metallic lithium, lithium alloy or lithium foil, or a combination of at least two of them.

[0031] As a preferred embodiment of the present invention, the solvent A includes any one of 1,2-dimethoxyethane (DME), tetrahydrofuran (THF) or 2-methyltetrahydrofuran (THF) or a combination of at least two thereof.

[0032] As a preferred embodiment of the present invention, the solvent B includes any one of heptane, xylene, anisole, petroleum ether or butyl butyrate, or a combination of at least two of them, and a combination of no more than three of them.

[0033] In a second aspect, the specific implementation mode of the present invention provides a method for preparing the aforementioned chemical pre-lithiation reagent, the preparation method comprising: adding a lithium source to a mixture of an aromatic compound and a solvent A, stirring and mixing, and then adding a solvent B to obtain a chemical pre-lithiation reagent.

[0034] As a preferred embodiment of the present invention, the concentration of the aromatic compound in the mixture of the aromatic compound and the solvent A is 0.01mol / L-10mol / L, for example, 0.01mol / L, 0.05mol / L, 0.1mol / L, 0.5mol / L, 1mol / L, 3mol / L, 5mol / L, 7mol / L or 10mol / L, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] As a preferred embodiment of the present invention, the stirring rate of the stirring and mixing is 100r / min-8000r / min; for example, 100r / min, 300r / min, 500r / min, 800r / min, 1000r / min, 1500r / min, 2000r / min, 2500r / min, 3000r / min, 3500r / min, 4000r / min, 4500r / min, 5000r / min, 5500r / min, 6000r / min, 6500r / min, 7000r / min, 7500r / min or 8000r / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 500r / min-2000r / min.

[0036] In a third aspect, a specific embodiment of the present invention provides a pre-lithiated negative electrode plate, wherein the negative electrode plate is obtained by treating with the aforementioned chemical pre-lithiation reagent.

[0037] As a preferred embodiment of the present invention, the negative electrode plate includes any one of a silicon-based negative electrode plate, a graphite negative electrode plate or an alloy-type negative electrode plate.

[0038] In a fourth aspect, the specific implementation of the present invention provides a method for preparing the negative electrode plate as described above, the preparation method comprising: soaking the negative electrode plate in a chemical pre-lithiation reagent and then drying;

[0039] Alternatively, a chemical pre-lithiation agent is applied to the negative electrode plate and then dried.

[0040] As a preferred embodiment of the present invention, the soaking time is 1 min-600 min.

[0041] In a fourth aspect, a specific embodiment of the present invention provides a sulfide solid-state battery, wherein the negative electrode used in the sulfide solid-state battery is the aforementioned pre-lithiated negative electrode plate.

[0042] The following are typical but non-limiting embodiments of the present invention:

[0043] Embodiment 1:

[0044] The present embodiment provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes biphenyl, metallic lithium, tetrahydrofuran and heptane, wherein the mass ratio of metallic lithium to biphenyl is 1:1, and the mass ratio of solvent heptane to solvent tetrahydrofuran is 1:1.

[0045] The preparation method of the chemical pre-lithiation reagent comprises:

[0046] After biphenyl and tetrahydrofuran are uniformly mixed to form a solution with a concentration of 1 mol / L, metallic lithium is added, dissolved and uniformly dispersed at a rotation speed of 1000 r / min; heptane is then added, and the mixture is uniformly mixed to obtain a chemical pre-lithiation reagent.

[0047] Embodiment 2:

[0048] The present embodiment provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes naphthalene, metallic lithium, 2-methyltetrahydrofuran and xylene, wherein the concentration of the mixed solution of naphthalene and 2-methyltetrahydrofuran is 1 mol / L, the mass ratio of metallic lithium to naphthalene is 1:1, and the mass ratio of solvent xylene to solvent 2-methyltetrahydrofuran is 1:1.

[0049] The preparation method of the chemical pre-lithiation reagent is the same as that of Example 1, except that the dissolution speed is 3000 r / min.

[0050] Embodiment 3:

[0051] The present embodiment provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes dimethylbiphenyl, metallic lithium, 1,2-dimethoxyethane and petroleum ether, wherein the concentration of the mixed solution of dimethylbiphenyl and 1,2-dimethoxyethane is 1 mol / L, the mass ratio of metallic lithium to dimethylbiphenyl is 1:1, and the mass ratio of solvent petroleum ether to solvent 1,2-dimethoxyethane is 1:1.

[0052] The preparation method of the chemical pre-lithiation reagent is the same as that of Example 1, except that the dissolution speed is 2500 r / min.

[0053] Embodiment 4:

[0054] The present embodiment provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes tetramethylbiphenyl, metallic lithium, tetrahydrofuran and anisole, wherein the concentration of the mixed solution of tetramethylbiphenyl and tetrahydrofuran is 1 mol / L, the mass ratio of metallic lithium to tetramethylbiphenyl is 1:1, and the mass ratio of solvent anisole to solvent tetrahydrofuran is 2:1.

[0055] The preparation method of the chemical pre-lithiation reagent is the same as that in Example 1.

[0056] Embodiment 5:

[0057] The present embodiment provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes biphenyl, metallic lithium, tetrahydrofuran and butyl butyrate, wherein the concentration of the mixed solution of biphenyl and tetrahydrofuran is 1 mol / L, the mass ratio of metallic lithium to biphenyl is 1:1, and the mass ratio of solvent butyl butyrate to solvent tetrahydrofuran is 1:2.

[0058] The preparation method of the chemical pre-lithiation reagent is the same as that in Example 1.

[0059] Embodiment 6:

[0060] The present embodiment provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes tetramethylbiphenyl, metallic lithium, dimethyltetrahydrofuran and toluene, wherein the concentration of the chemical reagent mixed solution configured with tetramethylbiphenyl and dimethyltetrahydrofuran is 0.2 mol / L, the mass ratio of the metallic lithium and dimethylbiphenyl added subsequently is 3:1, and the mass ratio of the added solvent toluene and the solvent dimethyltetrahydrofuran is 3:1.

[0061] The preparation method of the chemical pre-lithiation reagent is the same as that in Example 1.

[0062] Embodiment 7:

[0063] The present embodiment provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes naphthalene, metallic lithium, tetrahydrofuran and butyl butyrate, wherein the concentration of the chemical reagent mixed solution configured with naphthalene and tetrahydrofuran is 0.5 mol / L, the mass ratio of the metallic lithium and naphthalene added subsequently is 4:1, and the mass ratio of the added solvent butyl butyrate and the solvent tetrahydrofuran is 5:1.

[0064] The preparation method of the chemical pre-lithiation reagent is the same as that in Example 1.

[0065] Comparative Example 1:

[0066] This comparative example provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes biphenyl, metallic lithium and tetrahydrofuran, wherein the concentration of the chemical reagent configured with biphenyl and tetrahydrofuran is 1 mol / L, and the mass ratio of metallic lithium to biphenyl added subsequently is 1:1.

[0067] The preparation method of the chemical pre-lithiation reagent comprises:

[0068] After biphenyl and tetrahydrofuran are uniformly mixed, metallic lithium is added, dissolved and uniformly dispersed at a rotation speed of 500 r / min to obtain a chemical pre-lithiation reagent.

[0069] Comparative Example 2:

[0070] This comparative example provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes biphenyl, metallic lithium and heptane, wherein the concentration of the chemical reagent configured with biphenyl and heptane is 1 mol / L, and the mass ratio of metallic lithium to biphenyl added subsequently is 1:1.

[0071] The preparation method of the chemical pre-lithiation reagent comprises:

[0072] After biphenyl and heptane are uniformly mixed, metallic lithium is added, dissolved and uniformly dispersed at a rotation speed of 1500 r / min to obtain a chemical pre-lithiation reagent.

[0073] Comparative Example 3:

[0074] This comparative example provides a chemical pre-lithiation reagent and a preparation method thereof, wherein the chemical pre-lithiation reagent includes naphthalene, metallic lithium and 1,2-dimethoxyethane, wherein the concentration of the chemical reagent configured with naphthalene and 1,2-dimethoxyethane is 1 mol / L, and the mass ratio of metallic lithium to naphthalene added subsequently is 1:1.

[0075] The preparation method of the chemical pre-lithiation reagent comprises:

[0076] After naphthalene and 1,2-dimethoxyethane are uniformly mixed, metallic lithium is added, and dissolved and dispersed uniformly at a rotation speed of 1000 r / min to obtain a chemical pre-lithiation reagent.

[0077] Comparative Example 4:

[0078] This comparative example provides a chemical pre-lithiation reagent and a preparation method thereof. The composition and preparation method of the chemical pre-lithiation reagent are the same as those in Example 1, except that the mass ratio of the solvent heptane to the solvent tetrahydrofuran is 0.05:1.

[0079] Comparative Example 5:

[0080] This comparative example provides a chemical pre-lithiation reagent and a preparation method thereof. The composition and preparation method of the chemical pre-lithiation reagent are the same as those in Example 1, except that the mass ratio of the solvent heptane to the solvent tetrahydrofuran is 15:1.

[0081] Comparative Example 6:

[0082] This comparative example provides a chemical pre-lithiation reagent and a preparation method thereof. The composition and preparation method of the chemical pre-lithiation reagent are the same as those in Example 1, except that the mass ratio of the solvent heptane to the solvent tetrahydrofuran is 1:0.05.

[0083] Comparative Example 7:

[0084] This comparative example provides a chemical pre-lithiation reagent and a preparation method thereof. The composition and preparation method of the chemical pre-lithiation reagent are the same as those in Example 1, except that the mass ratio of the solvent heptane to the solvent tetrahydrofuran is 1:10.

[0085] The chemical pre-lithiation reagent in Example 1-7 and Comparative Example 1-7 is used to treat the silicon-based negative electrode plate. The specific method includes: soaking the silicon-based negative electrode plate in the chemical pre-lithiation reagent for 20 minutes and then drying it.

[0086] Sulfide solid-state batteries were prepared using silicon-based negative electrode plates treated with the chemical pre-lithiation reagents in Examples 1-7 and Comparative Examples 1-7, and performance tests were performed on them. The results are shown in Table 1.

[0087] Table 1: Performance test table of sulfide solid-state batteries

[0088]

[0089]

[0090] As can be seen from Table 1, the addition of solvent A can be beneficial to the formation of pre-lithiation reagents, achieve the purpose of pre-lithiation, and improve the initial efficiency and energy density of the battery, but too much proportion will affect the cycle life of the battery because solvent A will inevitably react with the sulfide solid electrolyte. The addition of solvent B can reduce the proportion of solvent A, and minimize the side reactions derived from the sulfide solid electrolyte without affecting the pre-lithiation effect, thereby reducing the impact on the battery cycle life.

[0091] The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A chemical pre-lithiation reagent, characterized in that The chemical pre-lithiation reagent comprises an aromatic compound, a lithium source, a solvent A and a solvent B, wherein the concentration of the aromatic compound in the chemical pre-lithiation reagent is 0.0009 mol / L-8.5 mol / L, the mass ratio of the lithium source to the aromatic compound is (1-10):(10-1), the mass ratio of the solvent B to the solvent A is (1-10):(5-1); the polarity of the solvent A is 3-7; and the polarity of the solvent B is <3.

2. The chemical pre-lithiation reagent according to claim 1, characterized in that The aromatic compound includes any one of biphenyl, naphthalene, dimethylbiphenyl or tetramethylbiphenyl, or a combination of at least two thereof.

3. The chemical pre-lithiation reagent according to claim 1, characterized in that The lithium source includes any one of metallic lithium, lithium alloy or lithium foil, or a combination of at least two of them.

4. The chemical pre-lithiation reagent according to claim 1, characterized in that The solvent A includes any one of 1,2-dimethoxyethane, tetrahydrofuran or 2-methyltetrahydrofuran, or a combination of at least two thereof; Preferably, the solvent B comprises any one of heptane, xylene, anisole, petroleum ether or butyl butyrate, or a combination of at least two thereof.

5. A method for preparing the chemical pre-lithiation reagent according to any one of claims 1 to 4, characterized in that: The preparation method comprises: adding a lithium source to a mixture of an aromatic compound and a solvent A, stirring and mixing, and then adding a solvent B to obtain a chemical pre-lithiation reagent.

6. The preparation method according to claim 5, characterized in that: The concentration of the aromatic compound in the mixture of the aromatic compound and the solvent A is 0.01 mol / L-10 mol / L, preferably 1 mol / L; Preferably, the stirring rate of the stirring and mixing is 100 r / min-8000 r / min, preferably 500 r / min-2000 r / min.

7. A pre-lithiated negative electrode plate, characterized in that: The negative electrode plate is obtained by treating with a chemical pre-lithiation reagent as described in any one of claims 1 to 4; Preferably, the negative electrode plate includes any one of a silicon-based negative electrode plate, a graphite negative electrode plate or an alloy negative electrode plate.

8. A method for preparing a negative electrode sheet as claimed in claim 7, characterized in that: The preparation method comprises: soaking the negative electrode plate in a chemical pre-lithiation reagent and then drying; Alternatively, a chemical pre-lithiation agent is applied to the negative electrode plate and then dried.

9. The preparation method according to claim 8, characterized in that: The soaking time is 1 min-600 min.

10. A sulfide solid-state battery, characterized in that: The negative electrode used in the sulfide solid-state battery is the pre-lithiated negative electrode sheet described in claim 7.

Images