Aqueous zinc-ion battery

Abstract

The present invention discloses an aqueous zinc-ion battery, comprising: a positive electrode sheet, a negative electrode sheet and an electrolyte. The positive electrode material of the positive electrode sheet is a layered vanadium-based positive electrode material. Since cations and water molecules are inserted into the layers of vanadium pentoxide, the interlayer spacing is increased and the structure of the host material is supported and stabilized. Therefore, the fast and reversible insertion and extraction performance of charge and discharge ions can be improved, and the high rate and long cycle life of the layered vanadium-based positive electrode material can be achieved. The negative electrode sheet is a zinc foil with a surface coating. By defining the thickness of the surface coating to be 100 nm to 20 μm, the surface coating can prevent the zinc foil from directly contacting the electrolyte, and zinc will be deposited between the coating and the zinc foil during the charge and discharge process. In this way, the direct contact between zinc and the electrolyte is avoided, which helps to solve problems such as dendrites, corrosion and hydrogen evolution of the zinc negative electrode. Compared with the traditional aqueous zinc-ion battery, the electrochemical performance of this aqueous zinc-ion battery is enhanced.

Description

Technical Field

[0001] The present invention relates to the field of electrochemical energy storage, and more particularly to an aqueous zinc-ion battery. Background Art

[0002] Aqueous zinc-ion batteries (AZIBs) use high specific capacity (820 mAh g -1 )), low redox potential (-0.76 V vs. SHE), inexpensive, and stable metallic zinc as the negative electrode. Therefore, they have irreplaceable advantages and stand out among many new aqueous rechargeable metal-ion batteries, becoming the most popular research object in aqueous metal batteries. At the same time, zinc metal is one of the most promising choices for stretchable micro energy storage devices, which can meet the demanding requirements of flexible and wearable batteries, including high safety, economy, sustainability, and reliable power supply.

[0003] However, there are still many challenges in the positive electrode, negative electrode, and electrolyte of current AZIBs. Problems such as unstable structure and easy dissolution of the positive electrode material, zinc dendrites, zinc corrosion, hydrogen evolution, and narrow voltage window of the aqueous electrolyte have hindered the application of AZIBs in large-scale energy storage. Based on this, selecting suitable positive electrode materials and modifying the zinc negative electrode to optimize AZIBs from all aspects will be the future development direction of AZIBs. Summary of the Invention

[0004] Based on this, it is necessary to provide an aqueous zinc-ion battery that can solve the above problems.

[0005] An aqueous zinc-ion battery, comprising: a positive electrode sheet, a negative electrode sheet, and an electrolyte;

[0006] The positive electrode sheet includes a positive electrode current collector and a positive electrode active layer coated on the positive electrode current collector. The positive electrode active layer includes a layered vanadium-based positive electrode material, and the chemical formula of the layered vanadium-based positive electrode material is M x V2O5·nH2O, where 0.05 ≤ x ≤ 1, 0.5 ≤ n ≤ 10, and M is selected from at least one of NH4 + , alkali metal elements, alkaline earth metal elements, and transition metal elements;

[0007] The negative electrode sheet is a zinc foil with a surface coating, and the thickness of the surface coating is 100 nm to 20 μm. The surface coating is used to prevent the zinc foil from directly contacting the electrolyte;

[0008] The electrolyte is a gel electrolyte containing a zinc salt and a polymer.

[0009] In one embodiment, M is selected from Li + , Na + , K +, Ni + , NH4 + , Mg 2+ , Zn 2+ , Ca 2+ , Co 2+ and Al 3+ and at least one of them.

[0010] In one embodiment, the surface coating is a metal surface coating, an inorganic surface coating, an organic surface coating or a conductive carbon material surface coating.

[0011] In one embodiment, the material of the metal surface coating is Cu or Sn, the material of the inorganic surface coating is Al2O3, TiO2, CaCO3, ZnF2 or ZnS, the material of the organic surface coating is polyvinyl butyral, polyamide or polyimide, and the thickness of the conductive carbon material surface coating is graphite, graphene, activated carbon or carbon nanotubes.

[0012] In one embodiment, the zinc salt is selected from at least one of ZnSO4, Zn(CH3COO)2, Zn(NO3)2, Zn(ClO4)2 and Zn(CF3SO3)2, and the polymer is selected from at least one of polyacrylamide, polyvinyl alcohol, polyethylene oxide and gelatin.

[0013] In one embodiment, in the electrolyte, the mass concentration of the zinc salt is 0.1 mol / kg to 20 mol / kg, and the mass concentration of the polymer is 0.1 mol / kg to 10 mol / kg;

[0014] In the electrolyte, the mass concentration ratio of the zinc salt to the polymer is 1:10 to 3:1.

[0015] In one embodiment, the layered vanadium-based cathode material is prepared by the following operations:

[0016] Prepare a mixed aqueous solution of a weak reducing agent and a salt containing cation M;

[0017] Add solid V2O5 powder to the mixed aqueous solution to form a mixed system; and

[0018] At 0 °C to 150 °C, after the mixed system reacts sufficiently, the required layered vanadium-based cathode material is obtained.

[0019] In one embodiment, the weak reducing agent is selected from at least one of organic acids, alcohols, aldehydes and amines, and the number of carbon atoms of the organic acids, the alcohols, the aldehydes and the amines does not exceed 60;

[0020] In the mixed aqueous solution, the concentration of the weak reducing agent is 0.001 mol / L to 1 mol / L.

[0021] In one embodiment, the concentration of the salt containing cation M is 0.01 mol / L to 2 mol / L;

[0022] In the mixed system, the weight percentage of the V2O5 solid powder to the solvent is 0.1% to 10%.

[0023] In one embodiment, the positive current collector is a stainless steel foil, a stainless steel mesh or a graphite paper;

[0024] The aqueous zinc ion battery further includes a housing, and the housing is a steel shell or an aluminum plastic film.

[0025] The positive electrode material of this aqueous zinc ion battery is a layered vanadium-based positive electrode material. Since cations and water molecules are inserted into the layers of vanadium pentoxide, the interlayer spacing is increased and the structure of the host material is supported and stabilized. Therefore, the fast and reversible insertion and extraction performance of charge and discharge ions can be improved, and the high rate and long cycle life of this layered vanadium-based positive electrode material can be realized.

[0026] In addition, the negative electrode sheet of this aqueous zinc ion battery is a zinc foil with a surface coating. By defining the thickness of the surface coating to be 100 nm to 20 μm, the surface coating can prevent the zinc foil from directly contacting the electrolyte, and zinc will be deposited between the coating and the zinc foil during charge and discharge. In this way, the direct contact between zinc and the electrolyte is avoided, which helps to solve problems such as dendrites, corrosion, and hydrogen evolution of the zinc negative electrode.

[0027] Compared with the traditional aqueous zinc ion battery, this aqueous zinc ion battery selects a layered vanadium-based positive electrode material as the positive electrode material and uses a core foil with a surface coating as the negative electrode sheet. Combining with the specific embodiments of the specification, the electrochemical performance of this aqueous zinc ion battery is enhanced. Description of the Drawings

[0028] 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 following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Among them:

[0030] Figure 1 It is the SEM image of the sodium ion intercalated layered vanadium-based positive electrode material prepared in Example 1.

[0031] Figure 2is the cycling performance graph of the aqueous zinc-ion battery prepared in Example 1 at a current density of 1 Ag -1

[0032] Figure 3 is the cycling performance graph of the aqueous zinc-ion battery prepared in Example 2 at a current density of 1 Ag -1

[0033] Figure 4 is the cycling performance graph of the aqueous zinc-ion battery prepared in Example 3 at a current density of 1 Ag -1 Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. 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.

[0035] The present invention discloses an aqueous zinc-ion battery in an embodiment, including: a positive electrode sheet, a negative electrode sheet, and an electrolyte solution.

[0036] The positive electrode sheet includes a positive electrode current collector and a positive electrode active layer coated on the positive electrode current collector. The positive electrode active layer includes a layered vanadium-based positive electrode material. The chemical formula of the layered vanadium-based positive electrode material is M x V2O5·nH2O, where 0.05 ≤ x ≤ 1, 0.5 ≤ n ≤ 10, and M is selected from at least one of NH4 + , alkali metal elements, alkaline earth metal elements, and transition metal elements.

[0037] The negative electrode sheet is a zinc foil with a surface coating. The thickness of the surface coating is 100 nm to 20 μm, and the surface coating is used to prevent the zinc foil from directly contacting the electrolyte solution.

[0038] The electrolyte is a gel electrolyte containing a zinc salt and a polymer.

[0039] The positive electrode material of this aqueous zinc-ion battery is a layered vanadium-based positive electrode material. Since cations and water molecules are inserted into the layers of vanadium pentoxide, the interlayer spacing is increased and the structure of the host material is supported and stabilized. Therefore, the fast and reversible insertion and extraction performance of charge and discharge ions can be improved, and the high rate and long cycle life of this layered vanadium-based positive electrode material can be achieved.

[0040] ​​​In addition, the negative electrode of this aqueous zinc-ion battery is a zinc foil with a surface coating. By limiting the thickness of the surface coating to 100 nm to 20 μm, the surface coating can prevent the direct contact between the zinc foil and the electrolyte, and during the charge and discharge process, zinc will be deposited between the coating and the zinc foil, thus avoiding the direct contact between zinc and the electrolyte, which helps to solve problems such as dendrites, corrosion, and hydrogen evolution of the zinc negative electrode.

[0041] Compared with traditional aqueous zinc-ion batteries, this aqueous zinc-ion battery uses a layered vanadium-based cathode material as the cathode material and a core foil with a surface coating as the negative electrode sheet. Combining with the specific embodiments in the specification, the electrochemical performance of this aqueous zinc-ion battery is enhanced.

[0042] Preferably, in this embodiment, M is selected from + Li + Na + K + Ni + NH4 2+ Mg 2+ Zn 2+ Ca 2+ Co 3+ and at least one of Al.

[0043] Preferably, the positive electrode active layer further includes a conductive agent and a binder. The specific ratio of the layered vanadium-based cathode material, the conductive agent, and the binder can be set according to actual needs.

[0044] Preferably, in this embodiment, the positive electrode current collector is a stainless steel foil, a stainless steel mesh, or a graphite paper.

[0045] Preferably, in this embodiment, the surface coating is a metal surface coating, an inorganic surface coating, an organic surface coating, or a conductive carbon material surface coating.

[0046] Specifically, the material of the metal surface coating is Cu or Sn, the material of the inorganic surface coating is Al2O3, TiO2, CaCO3, ZnF2, or ZnS, the material of the organic surface coating is polyvinyl butyral, polyamide, or polyimide, and the thickness of the conductive carbon material surface coating is graphite, graphene, activated carbon, or carbon nanotubes.

[0047] Specifically, by selecting the above surface coating and limiting the thickness of the surface coating to 100 nm to 20 μm, on the one hand, the surface coating can prevent the direct contact between the zinc foil and the electrolyte, and on the other hand, the surface coating does not affect the entry and exit of ions, and during the charge and discharge process, zinc will be deposited between the coating and the zinc foil, thus avoiding the direct contact between zinc and the electrolyte, which helps to solve problems such as dendrites, corrosion, and hydrogen evolution of the zinc negative electrode.

[0048] Preferably, in this embodiment, the zinc salt is selected from at least one of ZnSO4, Zn(CH3COO)2, Zn(NO3)2, Zn(ClO4)2, and Zn(CF3SO3)2, and the polymer is selected from at least one of polyacrylamide, polyvinyl alcohol, polyethylene oxide, and gelatin.

[0049] Specifically, in this embodiment, the mass concentration of the zinc salt is 0.1 mol / kg to 20 mol / kg, and the mass concentration of the polymer is 0.1 mol / kg to 10 mol / kg.

[0050] In the electrolyte, the mass concentration ratio of the zinc salt to the polymer is 1:10 to 3:1.

[0051] Preferably, the aqueous zinc ion battery further includes a housing, and the housing is a steel shell or an aluminum plastic film.

[0052] In one embodiment, the layered vanadium-based cathode material is prepared by the following operations: preparing a mixed aqueous solution of a weak reducing agent and a salt containing cation M; adding V2O5 solid powder to the mixed aqueous solution to form a mixed system; and reacting the mixed system at 0 °C to 150 °C to obtain the required layered vanadium-based cathode material.

[0053] Generally, the weak reducing agent is selected from at least one of organic acids, alcohols, aldehydes, and amines, and the number of carbon atoms in the organic acids, alcohols, aldehydes, and amines does not exceed 60.

[0054] Specifically, in this embodiment, the weak reducing agent is selected from at least one of oxalic acid, citric acid, ascorbic acid, glucose, formaldehyde, tert-butanol, and tert-butylamine.

[0055] Generally, in the mixed aqueous solution, the concentration of the weak reducing agent is 0.001 mol / L to 1 mol / L.

[0056] The salt containing cation M is selected from at least one of ammonium salts, alkali metal salts, alkaline earth metal salts, and transition metal salts.

[0057] In the mixed aqueous solution, the concentration of the salt containing cation M is 0.01 mol / L to 2 mol / L.

[0058] In the present invention, precisely through the reduction reaction of the weak reducing agent with the pentavalent vanadium in vanadium pentoxide, the pre-intercalation reaction of cation M and water molecules can occur at a lower temperature and normal pressure, thereby obtaining the required layered vanadium-based cathode material.

[0059] Combined Figure 1 , it can be seen that the morphology of the vanadium-based cathode material prepared in the present invention changes from the initial granular V2O5 to a lamellar structure, indicating the successful insertion of ions and water molecules.

[0060] Specifically, the salt containing cation M can be a soluble sulfate, nitrate, acetate, chloride or perchlorate.

[0061] M is selected from at least one of NH4, alkali metal elements, alkaline earth metal elements and transition metal elements.

[0062] Preferably, in this embodiment, in the mixed aqueous solution, the molar ratio of the weak reducing agent to the salt containing cation M is 1:0.1 to 1:15.

[0063] Preferably, in this embodiment, in the mixed system, the weight percentage of V2O5 solid powder to the solvent is 0.1% to 10%.

[0064] More preferably, in the mixed system, the ratio of V2O5 solid powder to the weak reducing agent is 1:0.1 to 1:10.

[0065] Specifically, the operation to obtain the required layered vanadium-based cathode material after the mixed system reacts fully is: stirring the mixed system, and obtaining the required layered vanadium-based cathode material after reacting fully.

[0066] Preferably, in the operation of obtaining the required layered vanadium-based cathode material after the mixed system reacts fully, the reaction time is 5h to 72h.

[0067] Preferably, the reaction temperature is 60°C to 90°C.

[0068] The following are specific examples.

[0069] Example 1

[0070] Dissolve 0.2 mol of sodium sulfate in 2000 mL of water, add 0.3 mol of the weak reducing agent citric acid and stir to dissolve. Then add 0.2 mol (36.4 g) of vanadium pentoxide solid and stir and react at 60°C for 24 hours to obtain a layered vanadium-based cathode material with sodium ions pre-inserted. Figure 1 is the SEM image of the layered vanadium-based cathode material with sodium ions pre-inserted.

[0071] Combined with Figure 1 , it can be seen that the morphology of the vanadium-based cathode material prepared in Example 1 changes from the initial granular V2O5 to a lamellar structure, indicating the successful insertion of ions and water molecules.

[0072] Mix 70 mg of the above-mentioned layered vanadium-based cathode material with sodium ions pre-inserted, 20 mg of the conductive agent Ketjenblack and 10 mg of the binder PTFE evenly, coat them on stainless steel, cut them into a certain shape, and dry them in a vacuum drying oven to obtain a positive electrode sheet. Place the zinc foil in 0.2 mol L -1The SnCl2 solution was left for a certain period of time, and a layer of Sn with a thickness of 1 μm was plated on the surface of the zinc foil through a displacement reaction, thus obtaining the negative electrode sheet. 3M Zn(CF3SO3)2 aqueous solution, 10 mg mL -1 aqueous solution of N,N-methylenebisacrylamide (crosslinking agent), 5 mg mL -1 aqueous solution of ammonium persulfate (initiator), and PAM were mixed in a certain proportion to obtain the gel electrolyte. The positive electrode, negative electrode, and gel electrolyte were assembled into an aqueous zinc-ion battery.

[0073] After testing, the aqueous zinc-ion battery prepared in Example 1 had a stable discharge capacity of 385 mAh g -1 at a current density of 1 A g -1 (calculated based on the mass of the positive electrode active material), and after 500 cycles, the capacity did not show obvious attenuation, and the capacity retention rate was still close to 100%. The cycle performance diagram is as Figure 2 shown.

[0074] Example 2

[0075] 0.05 mol of zinc sulfate was dissolved in 2000 mL of water, and 0.3 mol of weak reducing agent tert-butanol was added and stirred until dissolved. Then 0.2 mol (36.4 g) of vanadium pentoxide solid was added and stirred at 70 °C for 60 hours to obtain a layered vanadium-based positive electrode material with zinc ions pre-inserted.

[0076] 70 mg of the above-mentioned layered vanadium-based positive electrode material with zinc ions pre-inserted, 20 mg of conductive agent Ketjenblack, and 10 mg of binder PTFE were mixed evenly and then coated on stainless steel, cut into a certain shape, and dried in a vacuum drying oven to obtain the positive electrode sheet. The zinc foil was placed in 0.1 mol L -1 of CuSO4 solution for a certain period of time, and a layer of copper with a thickness of 2 μm was plated on the surface of the zinc foil through a displacement reaction, thus obtaining the negative electrode sheet. 3M Zn(CF3SO3)2 aqueous solution, 10 mg mL -1 aqueous solution of N,N-methylenebisacrylamide (crosslinking agent), 5 mg mL -1 aqueous solution of ammonium persulfate (initiator), and PAM were mixed in a certain proportion to obtain the gel electrolyte. The positive electrode, negative electrode, and gel electrolyte were assembled into an aqueous zinc-ion battery.

[0077] After testing, the aqueous zinc-ion battery prepared in Example 2 had a stable discharge capacity of 310 mAh g -1 at a current density of 1 A g -1 (calculated based on the mass of the positive electrode active material), and after 500 cycles, the capacity did not show obvious attenuation, and the charge-discharge efficiency was still close to 99.9%. The cycle performance diagram is as Figure 3 shown.

[0078] Example 3

[0079] Dissolve 0.15 mol of magnesium sulfate in 2000 mL of water, add 0.1 mol of formaldehyde as a weak reducing agent and stir to dissolve. Then add 0.3 mol (54.6 g) of vanadium pentoxide solid and stir and react at 70 °C for 48 hours to obtain a layered vanadium-based cathode material with magnesium ions pre-intercalated.

[0080] Mix 70 mg of the above-mentioned layered vanadium-based cathode material with magnesium ions pre-intercalated, 20 mg of conductive agent Ketjenblack, and 10 mg of binder PTFE evenly, coat it on stainless steel, cut it into a certain shape, and dry it in a vacuum drying oven to obtain a positive electrode sheet. Place the zinc foil in a 0.1 mol L -1 copper sulfate solution for a certain period of time. A layer of copper with a thickness of 2 μm is plated on the surface of the zinc foil through a displacement reaction, and thus a negative electrode sheet is prepared. Mix 2 M ZnSO4 aqueous solution, 10 mg mL -1 N,N-methylenebisacrylamide aqueous solution (cross-linking agent), 5 mg mL -1 ammonium persulfate aqueous solution (initiator), and PAM in a certain proportion to obtain a gel electrolyte. Assemble the positive electrode, negative electrode, and gel electrolyte into an aqueous zinc-ion battery.

[0081] After testing, the aqueous zinc-ion battery prepared in Example 3 has a stable discharge capacity of 305 mAh g -1 at a current density of 1 Ag -1 (calculated based on the mass of the positive electrode active material), and the capacity does not show obvious attenuation after 500 cycles, and the capacity retention rate reaches 95%. The cyclic performance diagram is as shown in Figure 4 shown.

[0082] Example 4

[0083] Mix 70 mg of the layered vanadium-based cathode material with sodium ions pre-intercalated prepared in Example 1, 20 mg of conductive agent Ketjenblack, and 10 mg of binder PTFE evenly, coat it on stainless steel, cut it into a certain shape, and dry it in a vacuum drying oven to obtain a positive electrode sheet. Coat a 5 g L -1 PVB solution (solvent is N-methylpyrrolidone) on the zinc foil and dry it in a forced-air drying oven to obtain a negative electrode sheet. Mix 3 M Zn(CF3SO3)2 aqueous solution, 10 mg mL -1 N,N-methylenebisacrylamide aqueous solution (cross-linking agent), 5 mg mL -1 ammonium persulfate aqueous solution (initiator), and PAM in a certain proportion to obtain a gel electrolyte. Assemble the positive electrode, negative electrode, and gel electrolyte into an aqueous zinc-ion battery.

[0084] After testing, the aqueous zinc-ion battery prepared in Example 4 has a stable discharge capacity of 390 mAh g -1 at a current density of 1 A g -1 (calculated based on the mass of the positive electrode active material), and after 500 cycles, the capacity does not show significant attenuation, and the capacity retention rate is still close to 100%.

[0085] Example 5

[0086] 70 mg of the magnesium-ion pre-intercalated layered vanadium-based positive electrode material prepared in Example 3, 20 mg of the conductive agent Ketjenblack, and 10 mg of the binder PTFE were mixed evenly and then coated on stainless steel, cut into a certain shape, and dried in a vacuum drying oven to obtain the positive electrode sheet. 5 g L -1 of PVA solution (the solvent is N-methylpyrrolidone) was coated on the zinc foil and dried in a forced-air drying oven to obtain the negative electrode sheet. 3 M Zn(CF3SO3)2 aqueous solution, 10 mg mL -1 of N,N-methylenebisacrylamide aqueous solution (crosslinking agent), 5 mg mL -1 of ammonium persulfate aqueous solution (initiator), and PAM were mixed in a certain proportion to obtain the gel electrolyte. The positive electrode, negative electrode, and gel electrolyte were assembled into an aqueous zinc-ion battery.

[0087] After testing, the aqueous zinc-ion battery prepared in Example 5 has a stable discharge capacity of 350 mAh g -1 at a current density of 1 A g -1 (calculated based on the mass of the positive electrode active material), and after 500 cycles, the capacity does not show significant attenuation, and the capacity retention rate is still close to 98%.

[0088] Example 6

[0089] 0.1 mol of lithium nitrate was dissolved in 2000 mL of water, and 0.1 mol of the weak reducing agent oxalic acid was added and stirred to dissolve. Then 0.3 mol (54.6 g) of vanadium pentoxide solid was added and stirred at 95 °C for 24 hours to obtain the lithium-ion pre-intercalated layered vanadium-based positive electrode material.

[0090] 70 mg of the above lithium-ion pre-intercalated layered vanadium-based positive electrode material, 20 mg of the conductive agent Ketjenblack, and 10 mg of the binder PTFE were mixed evenly and then coated on stainless steel, cut into a certain shape, and dried in a vacuum drying oven to obtain the positive electrode sheet. The zinc foil was placed in a 0.2 mol L -1 of SnCl2 solution for a certain time, and a layer of Sn with a thickness of 1 μm was plated on the surface of the zinc foil through a displacement reaction, thus obtaining the negative electrode sheet. 3 M Zn(CF3SO3)2 aqueous solution, 10 mg mL -1 of N,N-methylenebisacrylamide aqueous solution (crosslinking agent), 5 mg mL-1 An aqueous ammonium persulfate solution (initiator) and PEO are mixed in a certain proportion to prepare a gel electrolyte. A positive electrode, a negative electrode, and the gel electrolyte are assembled into an aqueous zinc-ion battery.

[0091] After testing, the aqueous zinc-ion battery prepared in Example 6 has a stable discharge capacity of 360 mAh g -1 at a current density of 1 Ag -1 (calculated based on the mass of the positive electrode active material), and after 500 cycles, the capacity does not show obvious attenuation, and the capacity retention rate is still close to 100%.

[0092] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of this invention patent shall be subject to the appended claims.

Claims

1. Aqueous zinc ion battery, characterized in that, Comprising: a positive electrode sheet, a negative electrode sheet, and an electrolyte; The positive electrode plate includes a positive electrode current collector and a positive electrode active layer coated on the positive electrode current collector. The positive electrode active layer includes a layered vanadium-based positive electrode material, and the chemical formula of the layered vanadium-based positive electrode material is M x V2O5·nH2O, where 0.05 ≤ x ≤ 1, 0.5 ≤ n ≤ 10, and M is selected from at least one of NH4 + , alkali metal elements, alkaline earth metal elements, and transition metal elements; the layered vanadium-based positive electrode material is prepared by an oxidation-reduction reaction of V2O5 with an aqueous mixed solution of a weak reducing agent and a salt containing cation M; the negative electrode sheet is a zinc foil with a surface coating, the thickness of the surface coating is 100 nm to 20 μm, and the surface coating comprises one selected from Cu and Sn; the electrolyte is a gel electrolyte containing a zinc salt and a polymer.

2. The aqueous zinc ion battery according to claim 1, characterized in that, M is selected from Li + , Na + , K + , Ni + , NH4 + , Mg 2 + , Zn 2+ , Ca 2+ , Co 2+ and Al 3+ and at least one of them.

3. The aqueous zinc ion battery according to claim 1, characterized in that, the zinc salt is selected from at least one of ZnSO4, Zn(CH3COO)2, Zn(NO3)2, Zn(ClO4)2, and Zn(CF3SO3)2, and the polymer is selected from at least one of polyacrylamide, polyvinyl alcohol, polyethylene oxide, and gelatin; 4. The aqueous zinc ion battery according to claim 2, characterized in that, in the electrolyte, the mass concentration of the zinc salt is 0.1 mol / kg to 20 mol / kg, and the mass concentration of the polymer is 0.1 mol / kg to 10 mol / kg; in the electrolyte, the mass concentration ratio of the zinc salt to the polymer is 1:10 to 3:

1.

5. The aqueous zinc ion battery according to any one of claims 1 to 4, characterized in that, The layered vanadium-based positive electrode material is prepared by the following operations: preparing a mixed aqueous solution of a weak reducing agent and a salt containing cation M; adding V2O5 solid powder to the mixed aqueous solution to form a mixed system; and at 0°C to 150°C, after the mixed system reacts fully, the required layered vanadium-based positive electrode material is obtained.

6. The aqueous zinc ion battery according to claim 5, characterized in that, the weak reducing agent is selected from at least one of organic acids, alcohols, aldehydes, and amines, and the number of carbon atoms of the organic acids, the alcohols, the aldehydes, and the amines does not exceed 60; in the mixed aqueous solution, the concentration of the weak reducing agent is 0.001 mol / L to 1 mol / L.

7. The aqueous zinc ion battery according to claim 6, characterized in that, in the mixed aqueous solution, the concentration of the salt containing cation M is 0.01 mol / L to 2 mol / L; in the mixed system, the weight percentage of the V2O5 solid powder to the solvent is 0.1% to 10%.

8. The aqueous zinc ion battery according to claim 6, characterized in that, the positive electrode current collector is stainless steel foil, stainless steel mesh, or graphite paper; the aqueous zinc-ion battery further includes a casing, and the casing is a steel casing or an aluminum plastic film.

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