Sodium / potassium metal negative electrode and regeneration repair method and application thereof

Abstract

The invention belongs to the field of electrode materials, and particularly relates to a method for repairing and modifying a surface-alkalized metal M negative electrode, which comprises the following steps: coating the surface of the surface-alkalized metal M negative electrode with a treating fluid, and carrying out surface repairing and modifying treatment to prepare the surface-repaired and modified metal M negative electrode, the metal M is sodium and / or potassium; the treatment liquid is a solution containing at least one active component in a formula 1 # imgabs, a formula 0 # imgabs and a formula 2 # imgabs 1 #. The invention also comprises the regenerated metal M negative electrode prepared by the preparation method and application thereof. According to the process, the electrochemical performance of the modified material can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a method for repairing and modifying the surface of a sodium / potassium metal anode. Background Art

[0002] Compared with traditional carbon materials, sodium / potassium metals are regarded as the most promising anode materials for batteries due to their ultra-high theoretical specific capacity, light weight, and low redox potential. However, despite these unique advantages, it is still difficult to commercialize sodium / potassium metal batteries at the present stage. The reasons are as follows: compared with lithium metal, sodium / potassium metals have higher reactivity, stronger surface alkalinity, and softer texture. They are not only easily corroded by electrolytes to produce non-uniform deposition behavior, forming an unstable solid electrolyte interface (SEI) and dendrites; but also easily react with O2, H2O, CO2, etc. in the air to form an inert passivation layer on their surface or even deactivate them, resulting in economic losses. Moreover, even when stored in a glove box protected by inert gas, an inert layer will spontaneously form on its surface. Such problems increase the difficulty of assembling and storing metal batteries, and the energy density of the assembled full battery decreases significantly. In addition, the violent reaction of metal anodes in an environment with high humidity and high oxygen content and the piercing of the separator by dendrites will cause major problems such as fire and explosion, seriously endangering the lives and property safety of the people, and the consequences are unimaginable.

[0003] The prior art also provides some protection schemes for metal Na / K. For example, the Chinese patent document with the publication number CN115036447A discloses a protective coating for a lithium / sodium metal battery electrode sheet and a preparation method thereof, which is a protective coating formed after drying an Li / Na-Nafion solution on the surface of a metal electrode sheet; the Li / Na-Nafion solution is obtained by introducing equimolar amounts of Li+ and Na+ into Nafion. The Chinese patent document with the publication number CN110476283A discloses an electrochemically active protective layer, which is electrochemically active and includes a metal, wherein the metal includes Sn or In, and the protective layer is configured to reversibly accommodate ions in a manner of embedding formation, alloy formation, or both. Again, the Chinese patent document with the publication number CN114927649A discloses a method for preparing an environmentally compatible sodium metal anode, which includes sodium metal and a solid protective layer coated on the outer surface of the sodium metal, and the solid protective layer is a mixture of PEO, paraffin, and sodium salt.

[0004] In summary, although the prior art reports some few protection schemes for metal Na, the existing schemes are difficult to target the surface-alkalized and inactivated metal Na / K objects, and it is difficult for the existing protection schemes to restore and enhance the electrochemical performance by utilizing their physical and chemical characteristics while achieving protection. Summary of the Invention

[0005] To overcome the drawbacks and deficiencies in the prior art, the first object of the present invention is to provide a method for repairing and modifying a surface-alkalized metal M negative electrode, aiming to repair and enhance it, thereby improving its air stability and electrochemical performance.

[0006] The second object of the present invention is to provide a surface-repaired and modified metal M negative electrode obtained by the above-mentioned repair and modification method and its application in a metal M secondary battery.

[0007] The third object of the present invention is to provide a metal M secondary battery equipped with the surface-repaired and modified metal M negative electrode.

[0008] Different from lithium metal, metal Na / K has greater surface activity, stronger surface alkalinity, softer texture, and is more likely to be corroded by the electrolyte to produce non-uniform deposition behavior and dendrites; it is more likely to be deeply deactivated and more difficult to repair. In addition, in the existing processes, in order to improve its air stability, a certain amount of electrochemical performance is mostly sacrificed, and it is difficult to balance high high-humidity stability and high electrochemical performance. In view of the modification and regeneration problems caused by the special physical and chemical characteristics of metal Na / K, the present invention provides the following improvement solutions through in-depth research:

[0009] A method for repairing and modifying a surface-alkalized metal M negative electrode, which comprises coating a treatment solution on the surface of the surface-alkalized metal M negative electrode, performing surface repair and modification treatment, and obtaining a surface-repaired and modified metal M negative electrode.

[0010] The metal M is sodium and / or potassium;

[0011] The treatment solution is a solution containing at least one active ingredient in Formula 1 and Formula 2;

[0012]

[0013] The R1 is an alkyl group with 1 to 6 carbon atoms; R2 and R3 are independently an alkyl group with 1 to 6 carbon atoms or an alkoxy group with 1 to 6 carbon atoms; the X is an alkylene group or an oxaalkylene group with 3 to C 10 ;

[0014] The R4 to R7 are independently an alkyl group, an olefin group or a phospholipid group with 1 to C 12 ;

[0015] The carbon atoms of the alkyl group, alkylene group and olefin group may carry substituents, and the substituents are at least one of a hydroxyl group, an alkoxy group, an alkanoyl group, an ester group, an amide group, a halogen, a nitro group, an olefin group, an alkyne group, a phenyl group, and an epoxy group.

[0016] Aiming at the problems of difficult repair and efficiency increase caused by the special physical and chemical characteristics of metallic Na / K, the present invention innovatively uses at least one active ingredient in Formula 1 and Formula 2 to treat its surface. Based on the special physical and chemical characteristics of the surface of metal M and the chemical interactions (such as grafting, polycondensation, ring-opening reaction, etc.) between the active ingredients, a double protective layer with a rich ion-conducting network inside and a hydrophobic interface constructed on the outer layer can be chemically anchored on the surface of metal M. This helps to improve the stability of the interface, enables it to resist the influence of high-humidity environments. Moreover, it also helps to improve its rate performance and long-term cycling stability in different temperature ranges.

[0017] In the present invention, the surface-alkalized metal M negative electrode is a metal M negative electrode with a surface oxidized and presenting alkalinity; further, it is a metal M negative electrode with a surface forming an alkaline layer due to being eroded by humid air.

[0018] In the present invention, the alkaline layer contains at least one of metal M hydroxides and carbonates.

[0019] In the present invention, the chemical combination of Formula 1 can unexpectedly match the physical and chemical characteristics of the surface of metallic Na / K, so it can unexpectedly synergistically solve the problem of surface deactivation of metallic Na / K. Moreover, it can also facilitate the chemical transformation between its surface characteristics and Formula 1, construct a special double protective interface, thereby improving its stability against high-humidity air, and further unexpectedly improving its rate performance and long-term cycling stability in different temperature ranges.

[0020] In the present invention, in Formula 1, R1 is an alkyl group with 1 to 4 carbon atoms; R2 and R3 are each independently an alkoxy group with 1 to 6 carbon atoms; X is an oxaalkylene group with 3 to C 10 of carbon atoms.

[0021] In the present invention, Formula 1 is a compound having the structure of Formula 1-A:

[0022]

[0023] In Formula 1-A, R1 is an alkyl group with 1 to 2 carbon atoms, and n is an integer from 1 to 3.

[0024] In the present invention, the preferably structured Formula 1-A can better match the physical and chemical characteristics of the surface of metallic Na / K, and can further synergistically improve the stability of the repaired metal M negative electrode against high-humidity air, as well as its rate performance and long-term cycling stability.

[0025] The present invention also provides a solution with an active ingredient containing a compound of Formula 2. Research unexpectedly shows that Formula 2 can better match the physical and chemical characteristics of the surface of metallic Na / K, and can further synergistically improve the stability of the repaired metal M negative electrode against high-humidity air, as well as its rate performance and long-term cycling stability.

[0026] In Formula 2 described above, R5 and R7 are each independently an alkyl group having 1 to 6 carbon atoms; R4 and R6 are each independently an olefin group with substituents or a phospholipid group with substituents;

[0027] The substituents are at least one of alkoxy, alkanoyl, ester, amide, phenyl, and epoxy groups;

[0028] Preferably, Formula 2 is a compound having a structure of Formula 2-A or Formula 2-B:

[0029]

[0030] In Formula 2-A, R5, R7, R8, and R9 are each independently an alkyl group having 1 to 4 carbon atoms;

[0031] R 10 is an alkyl group having 2 to 10 carbon atoms.

[0032] Preferably, the active ingredients of the present invention include Formula 1 and Formula 2, and the weight ratio of the two is preferably 1 to 10:1 to 10, and further can be 1 to 3:1 to 3. Research shows that using the preferred combination of Formula 1 and Formula 2 helps to further improve its moisture resistance stability and the long-range cycling effect in different temperature ranges.

[0033] In the present invention, the treatment liquid is a liquid active ingredient or a mixed solution of an active ingredient - organic solvent;

[0034] In the present invention, the organic solvent is a conventional solvent capable of dissolving the active ingredient, and further can be at least one of gasoline, benzene, toluene, isopropanol, tetrahydrofuran, diethylene glycol dimethyl ether, and acetone;

[0035] In the treatment liquid of the present invention, the content of the active ingredient is above 5 wt%, preferably above 50 wt%, further can be above 80 wt%, and even further can be above 90 wt%.

[0036] Research in the present invention shows that controlling the usage amount of the active ingredient in the treatment liquid helps to further improve the physical and chemical compatibility effect between metal M and the active ingredient, and helps to further improve the modification effect.

[0037] Preferably, calculated based on the surface area of the metal M negative electrode, the usage amount of the active ingredient in the treatment liquid is 5 to 55, preferably 20 to 30 μL / cm 2 ;

[0038] There is no special requirement for the coating thickness of the treatment liquid in the present invention. For example, it can be 0.2 to 1 mm;

[0039] In the present invention, the temperature in the surface repair and modification treatment stage is 15 - 80°C; considering the convenience of the process and the composition, it can be directly at room temperature, and specifically, the temperature can be 20 - 40°C.

[0040] In the present invention, the time for the surface repair and modification treatment can be 5 - 120 min. Considering the treatment efficiency, it can be further 8 - 20 min, and further can be 8 - 15 min.

[0041] In the present invention, after the surface repair and modification treatment, the excess treatment liquid is removed by wiping and evaporation.

[0042] The present invention also provides a surface repair and modified metal M negative electrode prepared by the above - mentioned method.

[0043] In the present invention, due to the above - mentioned modification method, the modified metal M negative electrode can be endowed with special physical and chemical characteristics, and the modified electrode with the above - mentioned characteristics prepared by the method can unexpectedly exhibit better high - humidity air stability and better electrochemical performance.

[0044] The present invention also provides an application of the surface repair and modified metal M negative electrode prepared by the above - mentioned method. Using it as the negative electrode to prepare a metal M secondary battery.

[0045] In the present invention, based on the known process, the metal M secondary battery required for the preparation of the modified metal M secondary battery of the present invention can be prepared.

[0046] The present invention also provides a metal M secondary battery, which includes an electric core and an electrolyte for soaking the electric core. The electric core includes a positive electrode, a separator and a negative electrode, and the negative electrode is the surface repair and modified metal M negative electrode prepared by the method of the present invention.

[0047] For the metal M secondary battery of the present invention, except for being equipped with the surface repair and modified metal M negative electrode of the present invention, other components and structural parts can be conventional.

[0048] Beneficial effects

[0049] The present invention innovatively uses at least one active ingredient in Formula 1 and Formula 2 to treat the surface of the alkalized metal M. Based on the chemical interaction (such as grafting, polycondensation, ring - opening reaction, etc.) between the special physical and chemical characteristics of the metal M surface and the above - mentioned active ingredient, a double - layer protective layer with a rich ion - conducting network inside and a hydrophobic interface constructed on the outer layer can be chemically anchored on the surface of the metal M. This helps to improve the interface stability, improve its high - humidity environment stability, and further improve its electrochemical performance such as rate and long - range cycle stability in different temperature ranges.

[0050] The described treatment method can uniformly remove the oxide layer on the surface of the metal negative electrode eroded by humid air, help the inactivated metal negative electrode restore its metallic luster, and at the same time restore its electrochemical activity; realize the recycling of sodium / potassium, and reduce the waste generated due to improper storage.

[0051] The metal M negative electrode treated by the present invention is not restricted by storage and assembly conditions, can be directly exposed to humid air, can remain stable in humid air with a humidity exceeding 60%, and maintain its high electrochemical activity, realizing battery assembly without inert gas protection and reducing its storage and assembly costs.

[0052] The metal M negative electrode treated by the present invention has a small initial polarization, does not require long-term activation, and can effectively prevent dendrite generation during repeated deposition / stripping processes.

[0053] The process of the present invention not only reduces the difficulty of storing and assembling metal batteries, improves the electrochemical performance of the batteries, but also provides a strategy for restoring the activity of metal negative electrodes eroded by humid air, solving the process and cost problems of metal batteries. Description of the Drawings

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0055] Figure 1 SEM image of the highly stable sodium metal negative electrode prepared in Example 1.

[0056] Figure 2 SEM image of the highly stable sodium metal negative electrode prepared in Example 1 after treatment in humid air.

[0057] Figure 3 SEM image of the sodium metal negative electrode eroded by humid air treated in Example 1.

[0058] Figure 4 Test diagram of the symmetrical battery of the highly stable sodium metal negative electrodes prepared in Examples 1 and 2.

[0059] Figure 5 Comparison diagram of the cycling performance of the sodium metal with an outer hydrophobic double-layer multifunctional SEI film prepared in Examples 1 and 2 and the original sodium metal negative electrode at 12C.

[0060] Figure 6Infrared characterization comparison diagram of the surface-attached outer-hydrophobic double-functional SEI film metal sodium prepared in Example 1 after the treatment of humid air and the original metal sodium negative electrode. Detailed implementation mode

[0061] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0062] The metal Na / K to be treated in the present invention is a conventional metal Na / K with surface oxidation and alkalization.

[0063] In the present invention, there is no special requirement for the coating thickness of the treatment liquid, and it only needs to evenly cover the surface of the metal Na / K to be treated.

[0064] In the present invention, after coating the treatment liquid, a conversion modification treatment is carried out. There is no special requirement for the temperature of this process. Considering the convenience of the treatment method, it can be at room temperature (for example, 20-40 °C).

[0065] Example 1

[0066] 1) Select the active ingredient of Formula 1-A-1 directly as the organic treatment liquid.

[0067]

[0068] 2) Under the protection of inert gas, directly coat the organic liquid on the metal sodium negative electrode to be treated (also called Pristine Na). The coating amount is 20 μL / cm 2 , (coat 20 μL of Formula 1-A-1 per square centimeter). After 10 minutes, wipe off the excess organic liquid with filter paper to obtain a high-stability sodium metal negative electrode (also called GPTMS@Na).

[0069] As Figure 1 shown, it is the scanning electron microscope image of the sodium metal negative electrode obtained by the preparation method of this Example 1. It can be clearly seen from the front side view that the organic layer adheres.

[0070] 3) Place the obtained sodium metal negative electrode in humid air with a relative humidity of 40%, and test its stability to air and moisture.

[0071] As Figure 2 shown, it is the scanning electron microscope image of the sodium metal negative electrode obtained by the preparation method of this Example 1 and the original sodium. In the figure, 2a is the original sodium metal negative electrode after being treated with humid air, and the surface layer is loose and broken, indicating that it is severely eroded by humid air. Figure 2b is the highly stable sodium metal anode after treatment in this case, which can remain stable when placed in air and no obvious by-products are generated.

[0072] As Figure 3 shown, the original sodium metal anode eroded by humid air is treated by the method of Example 1, and the loose inert layer on the surface is successfully removed to restore its metallic luster.

[0073] 4) The active material Na3V2(PO4)3 (NVP), the conductive agent carbon black, and the binder polyvinylidene fluoride (PVDF) are fully stirred and mixed in an appropriate amount of n-methylpyrrolidone (NMP) solvent according to a weight ratio of 8:1:1 to form a uniform positive electrode slurry; and this positive electrode slurry is coated on the positive electrode current collector Al foil, and after drying and rolling, a positive electrode plate is obtained; a sodium sheet with a thickness of 0.3 - 1.0 mm is used as the negative electrode;

[0074] 5) The positive / negative electrode plates prepared in steps 4) and 2) are assembled into a button cell in a glove box with a water and oxygen content < 0.5 ppm, and the battery case model is 2016 type battery case; and the electrolyte is added, and the positive electrode battery case, the positive electrode plate, the separator, the negative electrode plate, and the negative electrode battery case are stacked in sequence to obtain an assembled sodium metal full cell;

[0075] 6) Long cycle tests are carried out on the assembled sodium metal symmetric cell. At 30 °C, repeated stripping / deposition cycle tests of sodium metal are carried out at different current densities.

[0076] As Figure 4 shown, under the conditions of 0.25 - 4 mA / cm 2 , 0.25 mAh / cm 2 , the initial polarization voltage of GPTMS@Na in Example 1 used for the symmetric cell rate test is only 44 mV, the overpotential is small and stable, and the cycle life is longer; while the original sodium metal is as high as 210 mV and fails after 80 h of cycling.

[0077] 7) Long cycle tests are carried out on the assembled sodium metal full cell. At 30 °C, the sodium metal battery is charged to 3.8 V at a 12C rate (1C = 110 mAh / g), and then discharged to 2.5 V at a 12C rate, and the discharge capacity at this time is recorded as d1 (i.e., the initial discharge capacity), and it is cycled 1000 times, and the discharge capacity at this time is recorded as d2. 15 sodium metal batteries are tested in each group, and the average value is taken.

[0078] Sodium metal battery capacity retention rate at 30 °C = [d2 / d1] × 100%

[0079] As Figure 5As shown, the GPTMS@Na sodium metal anode processed using Example 1 exhibits stable long-term cycling over 1000 cycles at 12C, with a discharge specific capacity as high as 97.0 mAh / g and a capacity retention rate of 94.3%; while the untreated original sodium metal anode has a capacity of less than 35 mAh / g at ultra-high rates, and the Coulombic efficiency fluctuates severely. This demonstrates that the SEI film prepared in Example 1 can promote the rapid desolvation and uniform deposition of sodium ions, improving its electrochemical performance.

[0080] As Figure 6 shown, the sodium metal anode processed in Example 1 and the original sodium anode were placed in humid air with a humidity of 40% for 15 min, and infrared spectroscopy characterization was performed on them. It can be clearly seen that there is no obvious formation of inert inorganic products NaOH and Na2CO3 on the GPTMS@Na obtained in Example 1 after being exposed to humid air for 15 min, while the by-product peaks of the original sodium metal sheet are obvious. The reaction of the active sodium metal with air generates a large amount of loose inorganic products, which will lead to the decline and even inactivation of its electrochemical performance.

[0081] 8) The prepared sodium metal anode was placed in a high-humidity environment (RH = 60%) and left standing for 15 min. At 30°C, the sodium metal battery was charged to 3.8 V at a rate of 5C (1C = 110 mAh / g), and then discharged to 2.5 V at a rate of 5C. Record the discharge capacity at this time as d3 (i.e., the initial discharge capacity). Cycle 1000 times and record the discharge capacity at this time as d4. Fifteen sodium metal batteries were tested in each group, and the average value was taken.

[0082] Sodium metal battery capacity retention rate at 30°C = [d4 / d3] × 100%

[0083] 9) At 10°C, the sodium metal battery was charged to 3.8 V at a rate of 1C (1C = 110 mAh / g), and then discharged to 2.5 V at a rate of 1C. Record the discharge capacity at this time as d5 (i.e., the initial discharge capacity). Cycle 1000 times and record the discharge capacity at this time as d6. Fifteen sodium metal batteries were tested in each group, and the average value was taken.

[0084] Sodium metal battery capacity retention rate at 30°C = [d6 / d5] × 100%.

[0085] Example 2

[0086] Compared with Example 1, the only difference is that the active ingredient is replaced with Formula 2-A-1, and other operations and parameters are the same as in Example 1.

[0087]

[0088] As Figure 4 shown, at 0.25 - 4 mA / cm 2, 0.25 mAh / cm 2 Under the condition of 2, 3, 4 mA / cm 2 At high currents, the polarization voltage of the sodium metal anode prepared in Example 2 is only 300, 350, 380 mV, far superior to the metal anode prepared in Example 1, and has a longer cycle life.

[0089] As Figure 5 shown, the sodium metal anode treated with Example 2 exhibits stable ultra-long cycling of over 1000 cycles at 12C, with a high discharge specific capacity of 91.0 mAh / g, a capacity retention rate of 97.6%, and stable Coulomb efficiency.

[0090] Examples 3 - 6

[0091] The preparation method is basically the same as that of Example 1, with the difference that the active ingredients are respectively diluted with THF to form treatment liquids of 20wt%, 40wt%, 60wt%, and 80wt%, and then coating modification is carried out. Among them, the coating amounts of the active ingredients in each example are the same, and they are left standing at room temperature until the excess tetrahydrofuran volatilizes.

[0092] Examples 7 - 10

[0093] The preparation method is basically the same as that of Example 2, with the difference that the active ingredients are respectively diluted with THF to form treatment liquids of 20wt%, 40wt%, 60wt%, and 80wt%, and then coating modification is carried out. Among them, the coating amounts of the active ingredients in each example are the same, and they are left standing at room temperature until the excess tetrahydrofuran volatilizes.

[0094] Examples 11 - 13

[0095] The preparation method is basically the same as that of Example 1, with the difference that the coating amounts are 10, 30, 50 μL / cm 2 .

[0096] Examples 14 - 16

[0097] The preparation method is basically the same as that of Example 2, with the difference that the coating amounts are 10, 30, 50 μL respectively.

[0098] Example 17

[0099] Compared with Example 1, the difference is only that the active ingredient is replaced with Formula 1 - A - 2

[0100]

[0101] Example 18

[0102] Compared with Example 1, the difference is only that the active ingredient is replaced with Formula 2-B-1

[0103]

[0104] Example 19

[0105] Compared with Example 1, the difference is only that the active ingredient is replaced with a mixture of Formula 1-A-1 and 2-A-1 with a mass ratio of 1:1, and the total mass of the active ingredient is the same.

[0106] Comparative Example 1

[0107] Compared with Example 1, the difference is only that a sodium metal negative electrode without any treatment is used.

[0108] Comparative Example 2

[0109] Compared with Example 1, the difference is only that the active ingredient is replaced with Formula 1-A-3, which does not contain an epoxy group.

[0110]

[0111] The electrochemical performance of the materials in each case was studied by the method of Example 1, and the results are shown in Table 1.

[0112] Table 1 Test results of capacity retention performance at 30°C

[0113]

[0114]

[0115] Table 2 Test results of capacity retention performance of the metal negative electrode after being placed in a high-humidity environment (RH = 60%) for 15 minutes

[0116]

[0117] Table 3 Test results of capacity retention performance at 10°C

[0118]

[0119]

[0120] The active ingredients of Formula 1 and Formula 2 described in the present invention can adapt to the physical and chemical characteristics of metals Na and K, can improve the protection effect and can achieve electrochemical synergistic enhancement. For example, the treated negative electrode of the present invention has excellent electrochemical stability and tolerance to humid air. Even after being exposed to air with a humidity exceeding 60%, it will not lose its electrochemical activity, and after assembling a symmetric battery and a full cell, the battery performance will not be significantly lost. In particular, the combination of Formula 1 - Formula 2 can obtain an unexpectedly combined synergistic effect.

[0121] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for repairing and modifying a surface-alkalized metal M negative electrode, characterized in that, A treatment solution is coated on the surface of a surface-alkalized metal M negative electrode to perform surface repair and modification treatment, thereby obtaining a surface-repaired and modified metal M negative electrode; The metal M is sodium and / or potassium; The treatment solution is a solution containing at least one active ingredient in Formula 1 and Formula 2; The R1 is an alkyl group having 1 to 6 carbon atoms; R2 and R3 are each independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms; the X is an alkylene group or an oxaalkylene group having 3 to C 10 alkylene; wherein R4 to R7 are each independently an alkyl, alkenyl or phospholipid group of C1 to C 12 ; Substituents are allowed on the carbon of the alkyl, alkylene, or alkenyl group, and the substituents are at least one of hydroxyl, alkoxy, alkanoyl, ester, amide, halogen, nitro, alkenyl, alkynyl, phenyl, and epoxy groups.

2. The repair and modification method of the surface-alkalized metal M negative electrode according to claim 1, characterized in that, The surface-alkalized metal M negative electrode is a metal M negative electrode with a surface oxidized and presenting alkalinity; further, it is a metal M negative electrode with a surface forming an alkaline layer due to being eroded by humid air; Preferably, the alkaline layer contains at least one of metal M hydroxide and carbonate.

3. The repair and modification method of the surface-alkalized metal M negative electrode according to claim 1, characterized in that, In Formula 1 described above, R1 is an alkyl group having 1 to 4 carbon atoms; R2 and R3 are each independently an alkyloxy group having 1 to 6 carbon atoms; X is an oxaalkylene group having 3 to C 10 carbon atoms.

4. The repair and modification method of the surface-alkalized metal M negative electrode according to claim 3, characterized in that, Formula 1 is a compound having the structure of Formula 1-A: In Formula 1-A, R1 is an alkyl group with 1 to 2 carbon atoms, and n is an integer from 1 to 3.

5. The repair and modification method of the surface-alkalized metal M negative electrode according to claim 1, characterized in that, In Formula 2, R5 and R7 are each independently an alkyl group with 1 to 6 carbon atoms; R4 and R6 are each independently an alkenyl group with substituents or a phospholipid group with substituents; The substituents are at least one of alkoxy, alkanoyl, ester, amide, phenyl, and epoxy groups; Preferably, Formula 2 is a compound having the structure of Formula 2-A and Formula 2-B: In Formula 2-A, R5, R7, R8, and R9 are each independently an alkyl group with 1 to 4 carbon atoms; The described R 10 is an alkyl group having 2 to 10 carbons.

6. The repair and modification method of the surface-alkalized metal M negative electrode according to any one of claims 1 to 5, characterized in that, The treatment solution is a liquid active ingredient or a mixed solution of an active ingredient and an organic solvent; Preferably, the organic solvent is at least one of gasoline, benzene, toluene, isopropanol, tetrahydrofuran, diethylene glycol dimethyl ether, and acetone; Preferably, in the treatment solution, the content of the active ingredient is above 5 wt%, preferably above 50 wt%, further can be above 80 wt%, and even further can be above 90 wt%.

7. The repair and modification method of the surface-alkalized metal M negative electrode according to any one of claims 1 to 6, characterized in that, Based on the surface area of the metal M negative electrode, the usage amount of the active ingredient in the treatment liquid is 5 to 55, preferably 20 to 30 μL / cm 2 ; Preferably, the coating thickness of the treatment solution is 0.2 to 1 mm; Preferably, the temperature in the surface repair and modification treatment stage is 15 to 80 °C; Preferably, the time of the surface repair and modification treatment is 5 to 120 min; Preferably, after the surface repair and modification treatment, the excess treatment solution is removed by wiping and evaporation methods.

8. A surface-repaired and modified metal M negative electrode prepared by the method according to any one of claims 1 to 7.

9. Application of a surface-repaired and modified metal M negative electrode prepared by the method according to any one of claims 1 to 7, characterized in that Using it as a negative electrode to prepare a metal M secondary battery.

10. A secondary battery of metal M, comprising an electrode core and an electrolyte soaking the electrode core, wherein the electrode core includes a positive electrode, a separator and a negative electrode, characterized in that, The negative electrode is a surface-repaired and modified metal M negative electrode prepared by the method according to any one of claims 1 to 7.

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