CN114597482A

CN114597482A - In-situ preparation method of solid electrolyte interface for zinc battery cathode

Info

Publication number: CN114597482A
Application number: CN202210247084.3A
Authority: CN
Inventors: 黄靖云; 韩晓明; 苏小妹; 汪洋; 罗斌; 叶志镇
Original assignee: Wenzhou Zinc Times Energy Co ltd; Wenzhou Research Institute Of Zhejiang University
Current assignee: Wenzhou Zinc Times Energy Co ltd; Wenzhou Research Institute Of Zhejiang University
Priority date: 2022-03-14
Filing date: 2022-03-14
Publication date: 2022-06-07
Anticipated expiration: 2042-03-14
Also published as: CN114597482B

Abstract

The invention discloses an in-situ preparation method of a solid electrolyte interface for a zinc battery cathode, wherein the solid electrolyte interface material is ZnCrO₄Or ZnCr₂O₄The method is characterized in that chromate such as sodium chromate is used as a solute, common solutions such as water, ethanol and the like are used as solvents, citric acid and salts thereof are used as regulating and controlling additives, and a zinc chromate and zinc chromite Solid Electrolyte Interface (SEI) protective layer is generated by reaction on zinc-containing metal. Using ZnCrO₄@ Zn or ZnCr₂O₄The battery with the @ Zn electrode effectively isolates water contact, inhibits dendritic growth, hydrogen evolution and passivation of a zinc battery, and shows excellent and stable zinc plating/stripping performance.

Description

In-situ preparation method of solid electrolyte interface for zinc battery cathode

Technical Field

The invention belongs to the technical field of battery electrode material preparation, and relates to an in-situ preparation method of a solid electrolyte interface for a zinc battery cathode, which can solve the problem of serious side reactions such as dendrite growth, hydrogen evolution, passivation and the like faced by the current zinc ion battery, realize long-term low-voltage stable circulation under the conditions of high current density and high area capacity, and greatly improve the commercial application value of the zinc ion battery in the field of energy storage.

Background

With the rapid increase in demand for sustainable and clean energy applications, great efforts have been made to develop battery systems other than lithium-based batteries due to the scarce and expensive nature of lithium resources. Among them, Aqueous Zinc Ion Batteries (AZIBs) have become one of the most promising options for economic and high-capacity energy deployment due to their characteristics of low cost, environmental friendliness, and low flammability. The zinc metal anode has high richness, low toxicity and large theoretical capacity (820mAh g)^-1And 5855Ah L^-1) And the like. However, its notorious dendrite formation and side reactions (such as corrosion, passivation and hydrogen evolution) result in lower galvanization/stripping Coulombic Efficiency (CE), lower zinc electrode utilization and shorter lifetime.

In order to improve the reversibility and durability of Zn electrodes, several strategies have been proposed, including optimization of Zn electrode structure, introduction of artificial Solid Electrolyte Interface (SEI) protection layer, and electrolyte formulation. The construction of nanostructured Zn electrodes has proven to be an effective strategy to slow zinc dendrite growth. However, the complex manufacturing processes, low density, low capacity and surface-dependent side reactions (e.g. corrosion, hydrogen evolution) make these methods questionable for practical applications. The contact between the electrolyte and the surface of the zinc electrode can be blocked by establishing an artificial solid electrolyte interface, so that the occurrence of side reaction is inhibited. However, these unstable SEI layers are prone to degradation during electrochemical cycling,the metal Zn is easy to be damaged and separated from the surface of the Zn due to repeated volume change of the metal Zn. In addition, due to its lower ionic conductivity, lower Zn ion transfer number (t)_Zn2+) And poor interfacial contact with Zn, the artificial SEI layer has limited dendritic inhibition, inevitably leading to undesirable CE. While various electrolytes and additives have also been used to improve CEs and cycle life, the lack of a stable and effective SEI capping layer has hindered their success. On the other hand, by introducing a high concentration of electrolyte ("in-salt water"), the H in solution is significantly reduced₂The activity of O reduces the side reaction caused by water and improves the reversibility of the galvanizing/zinc stripping process. However, the high cost, high viscosity and poor wettability of high concentration electrolytes have hindered their practical application.

A key problem with zinc metal in aqueous electrolytes is the lack of a suitable SEI protective layer. The in-situ formation of the SEI layer is essential to suppress further consumption of the electrolyte, stabilize the metal anode and maintain high CEs. However, in aqueous electrolytes, building the SEI layer in situ on the Zn electrode is very challenging. In aqueous solutions, the reduction potential due to zinc deposition is relatively high (-0.76V vs Standard Hydrogen Electrode (SHE)), and the voltage window of water is limited, resulting in salt ions that are not easily decomposed. Although H is parasitic in Zn deposition process₂The precipitation increases the local pH and initiates the formation of a passivation layer (e.g., ZnO), but the passivation layer thus formed is insulating and loose and cannot be used as a functional SEI layer. Meanwhile, hydrogen evolution can cause the battery to bulge out, and the electrolyte dries out, resulting in battery failure.

To date, in situ SEI engineering of aqueous electrolyte zinc electrodes remains a significant challenge, and feasible design principles to achieve in situ SEI layers are a great demand for aqueous zinc chemistry. The invention adopts a rapid continuous chemical deposition method to stabilize the zinc anode, successfully grows ultrathin ZnCrO in situ by a simple and cheap decoration process₄And ZnCr₂O₄And the SEI in-situ protective layer realizes the long-term low-voltage stable charge-discharge cycle.

Disclosure of Invention

The invention aims to provide a solid-state battery for a zinc ion battery cathodeThe in-situ preparation method of the electrolyte interface (SEI) protective layer has the advantages of low cost and high efficiency, and simultaneously ZnCrO grows in situ₄Or ZnCr₂O₄The SEI is uniform and compact, the side reactions of hydrogen evolution and passivation are greatly inhibited, and long-period circulation is realized.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

an in-situ preparation method of a solid electrolyte interface for a zinc battery negative electrode comprises the following steps:

(1) through a wet chemical method, one or more of chromic anhydride or chromate is used as a solute, a solvent and a regulating additive are added, and ultrasonic dissolution is carried out until a transparent solution is obtained;

(2) under the acidic condition, zinc-containing metal is immersed in the solution, the reaction is continuously carried out, and the high-quality zinc chromate (ZnCrO) is generated by the in-situ reaction on the surface of the zinc-containing metal₄) Or zinc chromite (ZnCr)₂O₄) An SEI protective layer;

(3) the zinc-containing metal after the reaction was taken out, sufficiently washed to remove the reaction solution and dried.

In the technical scheme, the adopted solute is one or a mixture of more of chromic anhydride or a + 3-valent or + 6-valent chromium salt, such as chromic anhydride, sodium chromate, potassium chromate, sodium dichromate, potassium dichromate, sodium chromite, potassium chromite and the like.

The solvent used in the method can be one or more mixed solution of the following materials: water; alcohols containing 1, 2, 3 or 4 carbon atoms (C1-C4 alcohols), such as methanol, ethanol, isopropanol, and n-butanol.

The conditioning additive used may be one or more mixtures of citric acid or its salts.

The acidic condition can be provided by adopting various common inorganic/organic acids such as hydrochloric acid, nitric acid, sulfuric acid, formic acid, acetic acid and the like, and the pH is adjusted to be 1-5.

Further, the total concentration of the solute in the transparent solution in the step (1) is 10-50 g/L.

Further, the in-situ reaction time in the step (2) is more than 20 s.

Further, in the step (3), absolute ethyl alcohol or deionized water is adopted for cleaning for 3-5 times, the drying temperature is 60-80 ℃, and the drying time is 10-30 min.

Furthermore, the zinc-containing metal can be pure zinc metal or zinc-containing alloy, and the metal can be in the forms of metal foil, metal block, metal powder and the like. Finally prepared ZnCrO₄Or ZnCr₂O₄The SEI protective layer has uniform texture and strong adhesive force, and effectively inhibits the occurrence of side reaction.

The method has the advantages that:

the growth and preparation operations are simple and quick, the cost is low, and high-end material growth equipment is not needed like the conventional in-situ growth methods such as chemical vapor deposition, radio frequency magnetron sputtering and the like; ZnCrO₄/ZnCr₂O₄The SEI protective layer is deposited in situ, has high and stable adhesion with metal and can not fall off under strong ultrasound; preparation of ZnCrO₄/ZnCr₂O₄The SEI protective layer has good ductility, and the SEI layer can not fall off and be stripped after being randomly bent for many times; grown ZnCrO₄/ZnCr₂O₄The @ Zn negative electrode greatly inhibits the inevitable side reaction of the zinc ion battery, and the preparation of the high-performance zinc ion battery is realized.

Drawings

FIG. 1 is a scheme for preparing ZnCrO in example 1₄The reaction precursor solution of (1);

FIG. 2 is a process for preparing ZnCr in example 2₂O₄The reaction precursor solution of (1);

FIG. 3 shows ZnCrO obtained by growth in example 1₄@ Zn electrode;

FIG. 4 shows ZnCr obtained by growth in example 2₂O₄A @ Zn electrode;

FIG. 5 shows the use of ZnCrO in example 1₄Zn-MnO of @ Zn electrode₂Testing the performance of the battery;

FIG. 6 shows the use of ZnCr in example 2₂O₄Zn-MnO of @ Zn electrode₂Testing the performance of the battery;

FIG. 7 is a scanning electron micrograph of a section of the ZnCr2O4@ Zn foil prepared in example 3.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto:

example 1:

ZnCrO₄in situ preparation of SEI on Zn foil

1) 400mg of sodium chromate and 1.6g of citric acid reagent powder were weighed into an 80ml orange-capped bottle.

2) 40ml of deionized water and 5ml of hydrochloric acid (HCl) were added to the orange-capped bottle of 1) and dissolved with thorough stirring until a dark orange clear precursor solution was obtained.

3) Cutting 5x5 cm²High purity zinc foil of 99.9% purity was adhered on one side with polyimide tape and placed on the bottom of the petri dish.

4) To 3) was added 45ml of the reaction precursor solution prepared in 2), and the mixture was allowed to stand at room temperature.

5) After standing at room temperature for 15min, the zinc foil was taken out with a sharp-tipped forceps and carefully washed three times with absolute ethanol to remove the precursor solution.

6) Drying the cleaned zinc foil in a 60 ℃ oven for 10 minutes, and removing the polyimide adhesive tape to obtain ZnCrO₄The @ Zn foil can be used for preparing a high-performance zinc battery cathode.

Example 2:

ZnCr₂O₄in situ preparation of SEI on Zn foil

1) 1200mg of sodium chromate reagent powder was weighed into an 80ml orange-capped bottle.

2) 35ml of deionized water and 10ml of hydrochloric acid (HCl) were added to the orange-capped bottle of 1) and dissolved with thorough stirring until an orange clear precursor solution was obtained.

After standing at room temperature for 5min, the zinc foil was taken out with a sharp-tipped forceps and carefully washed three times with absolute ethanol to remove the precursor solution.

5) Drying the cleaned zinc foil in a 60 ℃ oven for 10 minutes, and removing the polyimide adhesive tape to obtain ZnCr₂O₄The @ Zn foil can be used for preparing a high-performance zinc battery cathode.

Example 3:

preparation of precursor solution

FIG. 1 is a scheme for preparing ZnCrO in example 1₄The solution of the reaction precursor is in a dark orange clear state, which shows that the solute is completely dissolved and stably exists, chromate ions in the solution are complexed with citric acid, the potential of a chromate redox electrode is reduced, and the chromate ions cannot be subjected to redox reaction with zinc to be converted into Cr³⁺(ii) a FIG. 2 is a process for preparing ZnCr in example 2₂O₄The solution is in an orange clear state as shown in fig. 1, which shows that the solute is completely dissolved and stably exists, and chromate in the solute is free, so that dichromate ions and zinc undergo redox reaction under acidic conditions.

Example 4:

preparation of electrode material of water-based zinc ion battery

FIG. 3 shows ZnCrO obtained by growth in example 1₄@ Zn electrode, lemon yellow in color, and ZnCrO₄Homogeneous layer texture and clear texture. Yellow is the intrinsic color of + 6-valent zinc chromate, and uniform lemon yellow indicates ZnCrO₄Successfully generating in situ; FIG. 4 shows ZnCr obtained by growth in example 2₂O₄@ Zn electrode, tan in color, and ZnCr₂O₄Homogeneous layer texture and clear texture. Brown is the intrinsic color of zinc chromite +3, and a uniform tan color indicates ZnCr₂O₄Successfully generated in situ.

Example 5:

test of cycle performance of aqueous zinc ion battery

FIG. 5 shows the use of ZnCrO in example 1₄ZnCrO of @ Zn electrode₄@Zn//MnO₂Batteries at 1A g^-1And (5) testing the cycle performance under the current density condition. ZnCrO₄@Zn//MnO₂The battery can keep normal operation in 900 circulation processes and maintain 60mAh g^-1The specific capacity of the zinc ion battery greatly improves the performance of the zinc ion battery; FIG. 6 shows the use of ZnCr in example 2₂O₄ZnCr of @ Zn electrode₂O₄@Zn//MnO₂The battery is 1Ag^-1And (5) testing the cycle performance under the current density condition. ZnCr₂O₄@Zn//MnO₂The battery can still normally operate after 2000 cycles, the performance of the zinc ion battery is greatly improved, and the ZnCr is shown₂O₄The @ Zn electrode successfully inhibits the growth of zinc dendrites and the occurrence of side reactions such as hydrogen evolution and passivation.

Example 6:

characterization and analysis of Scanning Electron Microscopy (SEM)

FIG. 7 shows ZnCr prepared in example 1₂O₄Scanning electron micrographs of sections of the @ Zn foil. The micrograph shows that the prepared ZnCr₂O₄The layer thickness is only about 700nm, and the storage capacity of the zinc foil is retained to the maximum extent. Simultaneously compact ZnCr₂O₄The layer can well protect the zinc foil below the layer, so that the zinc foil cannot directly contact with electrolyte to generate hydrogen evolution and passivation.

In addition, the ZnCrO prepared by the in-situ deposition method₄Or ZnCr₂O₄The SEI protective layer has high and stable adhesion with metal and does not fall off under strong ultrasound; and the SEI protective layer has good ductility, and the SEI layer does not fall off and peel off after being randomly bent for many times.

In conclusion, the wet chemical method provided by the invention realizes ZnCrO₄/ZnCr₂O₄In-situ controlled growth of the SEI capping layer. Using ZnCrO₄/ZnCr₂O₄The zinc ion battery adopting @ Zn as the cathode greatly inhibits the occurrence of side reactions such as hydrogen evolution, passivation and the like, shows excellent performance of long-term stable circulation, and promotes the commercial application of the zinc ion battery.

Claims

1. A method for the in situ preparation of a solid electrolyte interface for a zinc battery negative electrode, the method comprising the steps of:

(2) under the acidic condition, zinc-containing metal is immersed into the solution obtained in the step (1), the reaction is continuously carried out, and zinc chromate ZnCrO is generated on the surface of the zinc-containing metal through in-situ reaction₄Or zinc chromite ZnCr₂O₄An SEI protective layer;

(3) the zinc-containing metal after the reaction was taken out, sufficiently washed to remove the reaction solution, and dried.

2. The method of claim 1, wherein the chromate is one or more of a +3 or +6 chromium salt, the solvent is one or more of water or C1-C4 alcohols, and the conditioning additive is one or more of citric acid or a salt thereof.

3. The method of claim 1, wherein the zinc-containing metal is pure zinc or a zinc-containing alloy in the form of a metal foil, a metal block, or a metal powder.

4. The in-situ preparation method of the solid electrolyte interface for the negative electrode of the zinc battery as claimed in claim 1, wherein the total concentration of the solute in the solution in the step (1) is 10-50 g/L.

5. The in-situ preparation method of the solid electrolyte interface for the negative electrode of the zinc battery according to claim 1, wherein in the step (2), the acidic condition is that the pH is 1-5.

6. The method for preparing an interface of a solid electrolyte for a negative electrode of a zinc battery according to claim 1, wherein the in-situ reaction time in the step (2) is 20s or more.

7. The in-situ preparation method of the solid electrolyte interface for the negative electrode of the zinc battery according to claim 1, wherein the drying temperature in the step (3) is 60-80 ℃ and the drying time is 10-30 min.

8. The negative electrode material of the zinc ion battery is characterized by being ZnCrO₄@ Zn foil material, obtainable by a process according to any one of claims 1 to 7.

9. The negative electrode material of the zinc ion battery is characterized by being ZnCr₂O₄@ Zn foil material, obtainable by a process according to any one of claims 1 to 7.

10. A zinc ion battery comprising the negative electrode material according to claim 8 or 9.