Electrolyte for aqueous zinc ion battery, preparation method of electrolyte, aqueous zinc ion battery and electric equipment

Abstract

The invention relates to the technical field of zinc ion batteries, in particular to an electrolyte for a water-based zinc ion battery, a preparation method of the electrolyte, the water-based zinc ion battery and electric equipment. The electrolyte for the aqueous zinc ion battery comprises a first additive, a second additive, zinc salt and water, the first additive comprises tripolyphosphate, and the mass concentration of the first additive in the electrolyte is 1-10 mg / mL; the second additive comprises bis (trifluoromethylsulfonyl) imide salt, and the molar concentration of the second additive in the electrolyte is 5-25 mol / L. According to the electrolyte provided by the invention, the tripolyphosphate and the bis (trifluoromethylsulfonyl) imide salt are added at the same time, the tripolyphosphate and the bis (trifluoromethylsulfonyl) imide salt have a synergistic effect, the growth of zinc dendrites can be inhibited and the side reaction of interface hydrogen evolution can be relieved at the same time, and the zinc ion battery containing the electrolyte has excellent cycle performance in a high-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc ion batteries, and in particular to an electrolyte for an aqueous zinc ion battery and a preparation method thereof, an aqueous zinc ion battery and electrical equipment. Background Art

[0002] Lithium-ion batteries (LIBs) are a milestone technology in the field of energy storage. They have the advantages of high energy density, long cycle life, and low self-discharge. The use of LIBs has significantly improved the utilization efficiency of renewable energy such as wind and solar energy. However, the further development of LIBs is limited by the expensive and scarce lithium resources and the flammability of organic electrolytes. In contrast, zinc-ion batteries (ZIBs) have attracted more and more attention due to their unique advantages. First, the electrode and electrolyte materials used in ZIBs are abundant and low in cost. Secondly, the ionic conductivity of aqueous electrolytes is two orders of magnitude higher than that of organic electrolytes, which is expected to achieve high power density charging and discharging. At the same time, aqueous electrolytes have good stability, do not react chemically with water / oxygen in air atmosphere, and have high safety performance.

[0003] However, the problems faced by zinc negative electrodes, such as dendrite growth, hydrogen evolution reaction, and corrosion passivation, limit the large-scale application of ZIBs. The electrodeposition behavior of zinc is affected by the "tip effect". Specifically, the rough surface of the zinc negative electrode leads to an uneven interfacial electric field, and the charge is enriched at the tip protrusion, attracting zinc ions to aggregate and deposit. However, the stripping process of zinc ions is not affected by the tip effect. This continuous uneven deposition / uniform stripping causes dynamic growth at the protrusion of the negative electrode, eventually forming zinc dendrites. The uncontrolled growth of zinc dendrites can easily pierce the diaphragm, causing the battery to short-circuit and fail. At the same time, due to the Zn 2+ The standard reduction potential of Zn / Zn is lower than that of H2O / H2, so hydrogen evolution is inevitable during the zinc deposition process. The hydrogen evolution causes the battery to burst due to excessive internal pressure, which poses a safety hazard. - The accumulation accelerates the formation of the byproduct basic zinc sulfate, and the insoluble insulating byproduct covers the surface of the negative electrode to form a passivation layer, which hinders the rapid transfer of ions / electrons. It is worth noting that under high temperature conditions, the activity of molecules in the electrolyte, ion transport kinetics and electrochemical reaction rates increase with the increase in temperature. At the same time, the interfacial side reactions caused by water decomposition will be more severe, which will accelerate battery aging and even cause safety accidents.

[0004] In recent years, many optimization strategies have been reported around the key problems of zinc anodes such as zinc dendrite growth and interface side reactions, such as negative electrode structure design, interface functional coatings and electrolyte additives. The negative electrode structure design constructs a substrate material with a 3D structure to provide more zinc nucleation sites, reduce electrochemical polarization to alleviate zinc dendrite growth, but the negative electrode structure design has no obvious inhibitory effect on interface side reactions. The interface functional coating can isolate water molecules from contact with the zinc anode to avoid side reactions, but the operation of the coating is cumbersome and complicated, and the volume expansion during zinc deposition can easily destroy the interface protective layer and cause it to fail.

[0005] In contrast, electrolyte additives, as a simple, efficient and low-cost modification strategy, can significantly alleviate the above key problems. However, most of the additives reported so far can only solve a single problem and cannot achieve multi-angle optimization of the zinc negative electrode, so the modification effect is not obvious.

[0006] Therefore, it is urgent to develop a multifunctional electrolyte that can simultaneously inhibit the growth of zinc dendrites and alleviate the interfacial hydrogen evolution side reaction, thereby achieving high-temperature stable cycling of zinc-ion batteries.

[0007] In view of this, the present invention is proposed. Summary of the invention

[0008] The first object of the present invention is to provide an electrolyte for an aqueous zinc ion battery. Based on the synergistic effect of tripolyphosphate and bis(trifluoromethylsulfonyl)imide salt, the electrolyte can simultaneously inhibit zinc dendrite growth and alleviate the interface hydrogen evolution side reaction. The zinc ion battery containing the electrolyte has excellent cycle performance under high temperature environment. The problems of uneven zinc deposition, interface side reaction and deterioration of zinc ion battery performance under high temperature environment in the zinc negative electrode are solved.

[0009] The second object of the present invention is to provide a method for preparing an electrolyte for an aqueous zinc ion battery, which has the advantages of simple operation, low cost and suitability for large-scale production.

[0010] The third object of the present invention is to provide an aqueous zinc ion battery having good cycle performance under high temperature environment.

[0011] A fourth object of the present invention is to provide an electrical device.

[0012] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0013] The present invention provides an electrolyte for an aqueous zinc ion battery, comprising a first additive, a second additive, a zinc salt and water; wherein the first additive comprises tripolyphosphate, and the mass concentration of the first additive in the electrolyte is 1 to 10 mg / mL; the second additive comprises bistrifluoromethylsulfonyl imide salt, and the molar concentration of the second additive in the electrolyte is 5 to 25 mol / L.

[0014] Furthermore, the tripolyphosphate includes at least one of sodium tripolyphosphate, potassium tripolyphosphate and ammonium tripolyphosphate.

[0015] Furthermore, the bis(trifluoromethylsulfonyl)imide salt includes at least one of lithium bis(trifluoromethylsulfonyl)imide and sodium bis(trifluoromethylsulfonyl)imide.

[0016] Furthermore, the zinc salt includes zinc trifluoromethanesulfonate.

[0017] Furthermore, the molar concentration of the zinc salt in the electrolyte is 0.5 to 5 mol / L.

[0018] Furthermore, the mass concentration of the first additive in the electrolyte is 2 to 8 mg / mL.

[0019] Furthermore, the molar concentration of the second additive in the electrolyte is 10 to 20 mol / L.

[0020] The present invention further provides a method for preparing the electrolyte for an aqueous zinc ion battery, comprising the following steps: mixing a first additive, a second additive, a zinc salt and water.

[0021] The present invention further provides an aqueous zinc ion battery, comprising the electrolyte for the aqueous zinc ion battery.

[0022] The present invention also provides an electrical device, comprising the aqueous zinc ion battery.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The high-temperature electrolyte for aqueous zinc ion batteries provided by the present invention comprises tripolyphosphate and bis(trifluoromethylsulfonyl)imide salt, which have a synergistic effect and can effectively solve the problems of uneven zinc deposition at the zinc negative electrode, interfacial side reactions, and deterioration of zinc ion battery performance under high temperature environments. The zinc ion battery containing the electrolyte has excellent cycle performance under high temperature environments.

[0025] (2) The high-temperature electrolyte for aqueous zinc ion batteries provided by the present invention can further improve the high-temperature cycle stability of the zinc ion battery prepared from the electrolyte by controlling the concentrations of the first additive and the second additive.

[0026] (3) The high-temperature electrolyte for aqueous zinc ion batteries provided by the present invention has the advantages of being simple to obtain and low in cost. DETAILED DESCRIPTION

[0027] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0028] If there is no special explanation, in the present invention, "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "the first", "the second", "the third", "the fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0029] If there is no special explanation, the "include" and "comprising" mentioned in the present invention represent open-ended or closed-ended expressions. For example, the "include" and "comprising" may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0030] If there is no special explanation, in the present invention, "one or more" or "at least one" refers to any one, any two or more of the listed items. Among them, "several" refers to any two or more of the listed items.

[0031] In a first aspect, the present invention provides an electrolyte for an aqueous zinc ion battery containing a bifunctional additive, which includes a first additive, a second additive, a zinc salt and water.

[0032] Wherein, the first additive comprises tripolyphosphate, and the mass concentration of the first additive in the electrolyte is 1 to 10 mg / mL; including but not limited to any one of 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, 10 mg / mL or a range value between any two of them.

[0033] The second additive includes bistrifluoromethylsulfonyl imide salt, and the molar concentration of the second additive in the electrolyte is 5 to 25 mol / L, including but not limited to any one of 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L, 10 mol / L, 12 mol / L, 13 mol / L, 15 mol / L, 18 mol / L, 20 mol / L, 22 mol / L, 24 mol / L, and 25 mol / L, or a range between any two of them.

[0034] The high-temperature electrolyte for aqueous zinc ion batteries provided by the present invention can effectively solve the problems of uneven zinc deposition, interface side reactions and deterioration of zinc ion battery performance under high-temperature environments at zinc negative electrodes based on the synergistic effect of tripolyphosphate and bis(trifluoromethylsulfonyl)imide salts, and the decomposition of active water molecules is greatly restricted. The zinc ion battery containing the electrolyte has excellent cycle performance under high-temperature environments.

[0035] Specifically, first, the cations (e.g., Na + , K + NH4 + ) preferentially adsorbs at the tip of the zinc anode, weakens the "tip effect" through electrostatic shielding, promotes uniform deposition of zinc ions and inhibits the growth of zinc dendrites. 3- ) participates in adjusting the solvation shell of zinc ions to reduce the number of coordinated water molecules. At the same time, the bis(trifluoromethylsulfonyl)imide anion (TFSI - ) destroys the hydrogen bond network between water molecules. The reduction of water molecule activity in the bulk electrolyte is conducive to inhibiting the interfacial side reactions caused by the decomposition of H2O, thereby achieving high-temperature cycling stability of the zinc negative electrode. In addition, at the solid-liquid interface, tripolyphosphate anions and bistrifluoromethylsulfonyl imide anions decompose on the surface of the zinc negative electrode, forming an in-situ high-mechanical strength SEI protective film rich in P and F elements, blocking the direct contact between the zinc negative electrode and H2O, further inhibiting the interfacial side reactions, and improving the stability of the zinc negative electrode / electrolyte interface.

[0036] Furthermore, the present invention can further improve the high temperature cycle stability of the zinc ion battery prepared from the electrolyte by controlling the concentrations of the first additive and the second additive.

[0037] In addition, the above electrolyte has the advantages of being easy to obtain and low cost.

[0038] In some specific embodiments, the tripolyphosphate includes at least one of sodium polyphosphate (STPP), potassium tripolyphosphate (KTPP) and ammonium tripolyphosphate (ATPP).

[0039] In some specific embodiments, the bis(trifluoromethylsulfonyl)imide salt includes at least one of lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and sodium bis(trifluoromethylsulfonyl)imide (NaTFSI).

[0040] In some specific embodiments, the zinc salt comprises zinc trifluoromethanesulfonate (Zn(OTF)2).

[0041] In some specific embodiments, the molar concentration of the zinc salt in the electrolyte is 0.5-5 mol / L, including but not limited to any one of 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L, and 5 mol / L, or a range between any two of them.

[0042] In some specific embodiments, in order to further improve the high temperature cycle stability of the zinc ion battery prepared from the electrolyte, the mass concentration of the first additive in the electrolyte is 2 to 8 mg / mL, more preferably 4 to 6 mg / mL.

[0043] In some specific embodiments, in order to further improve the high temperature cycle stability of the zinc ion battery prepared from the electrolyte, the molar concentration of the second additive in the electrolyte is 10 to 20 mol / L, more preferably 13 to 17 mol / L.

[0044] In some specific embodiments, the water includes but is not limited to deionized water.

[0045] In a second aspect, the present invention provides a method for preparing the electrolyte for an aqueous zinc ion battery, comprising the following steps: uniformly mixing a first additive, a second additive, a zinc salt and water to obtain the electrolyte for an aqueous zinc ion battery.

[0046] The invention provides a method for preparing an electrolyte for an aqueous zinc ion battery, which adopts tripolyphosphate and bis(trifluoromethylsulfonyl)imide salt as electrolyte additives at the same time to prepare the electrolyte for an aqueous zinc ion battery, and can significantly improve the high-temperature cycle stability of the zinc ion battery.

[0047] In addition, the preparation method has the advantages of simple operation, low cost, green and pollution-free, and suitable for mass production.

[0048] It is understandable that there is no specific order for adding the first additive, the second additive and the zinc salt, and they can be arranged as needed, and the present invention does not limit this.

[0049] In some specific implementations, stirring may be performed to promote rapid dissolution and uniform mixing of the raw materials, which is not limited in the present invention.

[0050] In some specific embodiments, the mixing can be performed at room temperature without limiting the atmosphere.

[0051] In a third aspect, the present invention provides an aqueous zinc ion battery, comprising the electrolyte for an aqueous zinc ion battery.

[0052] The tripolyphosphate and bis(trifluoromethylsulfonyl)imide salt in the electrolyte provided by the invention have a synergistic effect, and the zinc ion battery containing the electrolyte has good cycle performance under high temperature environment.

[0053] Optionally, the aqueous zinc ion battery further includes a positive electrode sheet, a negative electrode sheet and a separator, which is not limited in the present invention.

[0054] As an example, the specification of the positive electrode sheet used in the zinc ion battery can be 12 mm in diameter. Further, the positive electrode material used in the zinc ion battery includes one or more of vanadium-based materials, manganese-based materials, Prussian blue analogs and organic materials, such as vanadium pentoxide (V2O5). Further, the specification of the negative electrode sheet used in the zinc ion battery can be 16 mm in diameter. Further, the negative electrode material used in the zinc ion battery can be commercial zinc foil (Zn). Further, the diaphragm used in the zinc ion battery can be a glass fiber diaphragm (GF / D). Further, the shell model used in the zinc ion battery can be CR2032, but is not limited thereto.

[0055] In a fourth aspect, the present invention provides an electrical device comprising the aqueous zinc ion battery.

[0056] Among them, electrical equipment includes any equipment, device or system using the above-mentioned aqueous zinc ion battery, such as electric vehicles, electric motorcycles, electric bicycles, power tools, energy storage systems, electronic products, office equipment, etc., but not limited to these.

[0057] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0058] Example 1

[0059] The electrolyte for an aqueous zinc ion battery provided in this embodiment includes sodium tripolyphosphate (STPP), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), zinc trifluoromethanesulfonate (Zn(OTF)2) and deionized water. The molar concentration of Zn(OTF)2 in the electrolyte is 2 mol / L, the mass concentration of STPP is 5 mg / mL, and the molar concentration of LiTFSI is 15 mol / L.

[0060] The preparation method of the electrolyte for aqueous zinc ion batteries provided in this embodiment comprises: using deionized water as a solvent and zinc trifluoromethanesulfonate as a solute, preparing a zinc trifluoromethanesulfonate solution with a molar concentration of 2 mol / L. Then, measuring 5 mL of the zinc trifluoromethanesulfonate solution, weighing 25 mg of sodium tripolyphosphate white powder and 0.075 mol of bis(trifluoromethanesulfonyl)imide lithium, adding the solution, and stirring evenly until the solution is completely dissolved, thereby obtaining an electrolyte for aqueous zinc ion batteries.

[0061] Example 2

[0062] The electrolyte for aqueous zinc ion batteries and the preparation method thereof provided in this embodiment are substantially the same as those in Example 1, except that the mass concentration of STPP in the electrolyte is 1 mg / mL, and the amount of STPP added is adaptively adjusted.

[0063] Example 3

[0064] The electrolyte for aqueous zinc ion batteries and the preparation method thereof provided in this embodiment are substantially the same as those in Example 1, except that the mass concentration of STPP in the electrolyte is 10 mg / mL, and the amount of STPP added is adaptively adjusted.

[0065] Example 4

[0066] The electrolyte for aqueous zinc ion batteries and the preparation method thereof provided in this embodiment are substantially the same as those in Example 1, except that the molar concentration of LiTFSI in the electrolyte is 5 mol / L, and the amount of LiTFSI added is adjusted adaptively.

[0067] Example 5

[0068] The electrolyte for aqueous zinc ion batteries and the preparation method thereof provided in this embodiment are substantially the same as those in Example 1, except that the molar concentration of LiTFSI in the electrolyte is 25 mol / L, and the amount of LiTFSI added is adjusted adaptively.

[0069] Example 6

[0070] The electrolyte for aqueous zinc ion batteries and the preparation method thereof provided in this embodiment are basically the same as those in Example 1, except that the molar concentration of Zn(OTF)2 in the electrolyte is 5 mol / L, and the amount of Zn(OTF)2 added is adaptively adjusted.

[0071] Example 7

[0072] The electrolyte for aqueous zinc ion batteries and the preparation method thereof provided in this embodiment are substantially the same as those in Example 1, except that sodium tripolyphosphate is replaced by potassium tripolyphosphate.

[0073] Example 8

[0074] The electrolyte for aqueous zinc ion batteries and the preparation method thereof provided in this embodiment are substantially the same as those in Example 1, except that sodium tripolyphosphate is replaced by ammonium tripolyphosphate.

[0075] Example 9

[0076] The electrolyte for aqueous zinc ion battery and the preparation method thereof provided in this embodiment are substantially the same as those in Example 1, except that lithium bistrifluoromethylsulfonyl imide is replaced by sodium bistrifluoromethylsulfonyl imide.

[0077] Comparative Example 1

[0078] The electrolyte and preparation method thereof provided in this comparative example are substantially the same as those in Example 1, except that lithium bis(trifluoromethylsulfonyl)imide is replaced by lithium nitrate of equal molar concentration.

[0079] Comparative Example 2

[0080] The electrolyte and preparation method thereof provided in this comparative example are substantially the same as those in Example 1, except that sodium tripolyphosphate is replaced by sodium nitrate of equal mass concentration.

[0081] Comparative Example 3

[0082] The electrolyte and preparation method thereof provided in this comparative example are substantially the same as those in Example 1, except that lithium bistrifluoromethylsulfonyl imide is replaced by lithium nitrate of equal molar concentration, and sodium tripolyphosphate is replaced by sodium nitrate of equal mass concentration.

[0083] Comparative Example 4

[0084] The electrolyte and preparation method thereof provided in this comparative example are substantially the same as those in Example 1, except that the mass concentration of STPP in the electrolyte is 15 mg / mL, and the amount of STPP added is adjusted adaptively.

[0085] Comparative Example 5

[0086] The electrolyte and preparation method thereof provided in this comparative example are substantially the same as those in Example 1, except that the molar concentration of LiTFSI in the electrolyte is 30 mol / L, and the amount of LiTFSI added is adjusted adaptively.

[0087] Experimental example

[0088] The zinc ion batteries were prepared using the electrolytes prepared in the embodiments and comparative examples, and the zinc ion batteries were subjected to room temperature (25° C.) cycle performance tests and high temperature (60° C.) cycle performance tests. The test results are shown in Table 1.

[0089] The preparation method of the zinc ion battery includes: cleaning the zinc foil with ethanol, punching it into a circular pole piece with a diameter of 16 mm as the negative electrode. Mixing V2O5, conductive carbon black and PVDF in a proper amount of NMP at a mass ratio of 7:2:1, and then coating it on a titanium foil, and then punching it into a circular pole piece with a diameter of 12 mm after drying, as the positive electrode (active material loading is 1 mg / cm 2 ). The V2O5 / Zn zinc ion full battery is assembled in the order of negative electrode shell-negative electrode sheet-diaphragm-electrolyte-positive electrode sheet-steel sheet-spring-positive electrode shell.

[0090] The test method for room temperature (25°C) cycle performance and high temperature (60°C) cycle performance includes: using a constant current charge and discharge instrument, in a high temperature environment of 60°C and a room temperature environment of 25°C, at a scan rate of 5A / g, to test the cycle performance of the zinc ion battery, and the voltage window is set to 0.2~1.6V.

[0091] Table 1 Performance test results of various zinc ion batteries

[0092] Group Capacity retention after 2000 cycles at room temperature Capacity retention after 2000 cycles at 60℃ Example 1 78.2％ 55.6％ Example 2 58.8％ 40.5％ Example 3 63.5％ 42.7％ Example 4 53.4％ 38.6％ Example 5 55.3％ 45.9％ Example 6 67.4％ 47.7％ Example 7 73.2％ 52.1％ Example 8 75.1％ 52.3％ Example 9 71.9％ 49.2％ Comparative Example 1 42.8％ 31.4％ Comparative Example 2 47.5％ 35.6％ Comparative Example 3 34.4％ 17.7％ Comparative Example 4 52.4％ 39.8％ Comparative Example 5 50.8％ 38.2％

[0093] Combined with Table 1, it can be seen from Example 1 and Comparative Example 1, Comparative Example 2, and Comparative Example 3 that, compared with the battery without tripolyphosphate and bis(trifluoromethylsulfonyl)imide salt, the addition of tripolyphosphate and bis(trifluoromethylsulfonyl)imide salt can significantly improve the cycle capacity retention rate of the zinc ion battery.

[0094] By comparing Example 1 and Comparative Examples 4 and 5, it can be seen that when the concentration of tripolyphosphate or bis(trifluoromethylsulfonyl)imide salt is too high, the ionic conductivity in the bulk electrolyte will be reduced, the zinc ions will be bound by anions, the diffusion resistance will increase, and the cycle performance will be significantly reduced.

[0095] In summary, the high-temperature electrolyte provided by the present invention simultaneously adds tripolyphosphate and bis(trifluoromethylsulfonyl)imide salt, and the two have a synergistic effect. The electrolyte can simultaneously inhibit the growth of zinc dendrites and alleviate the interfacial hydrogen evolution side reaction. The zinc ion battery containing the electrolyte has excellent cycle performance under high temperature environment.

[0096] Although the present invention has been illustrated and described with specific embodiments, it should be appreciated that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents without departing from the spirit and scope of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. An electrolyte for an aqueous zinc ion battery, characterized in that: comprising a first additive, a second additive, a zinc salt and water; Wherein, the first additive comprises tripolyphosphate, and the mass concentration of the first additive in the electrolyte is 1 to 10 mg / mL; The second additive includes bis(trifluoromethylsulfonyl)imide salt, and the molar concentration of the second additive in the electrolyte is 5 to 25 mol / L.

2. The electrolyte for aqueous zinc ion batteries according to claim 1, characterized in that: The tripolyphosphate includes at least one of sodium tripolyphosphate, potassium tripolyphosphate and ammonium tripolyphosphate.

3. The electrolyte for aqueous zinc ion batteries according to claim 1, characterized in that: The bis(trifluoromethylsulfonyl)imide salt includes at least one of lithium bis(trifluoromethylsulfonyl)imide and sodium bis(trifluoromethylsulfonyl)imide.

4. The electrolyte for aqueous zinc ion batteries according to claim 1, characterized in that: The zinc salt includes zinc trifluoromethanesulfonate.

5. The electrolyte for aqueous zinc ion battery according to claim 1, characterized in that: The molar concentration of the zinc salt in the electrolyte is 0.5 to 5 mol / L.

6. The electrolyte for aqueous zinc ion batteries according to claim 1, characterized in that: The mass concentration of the first additive in the electrolyte is 2-8 mg / mL.

7. The electrolyte for aqueous zinc ion batteries according to claim 1, characterized in that: The molar concentration of the second additive in the electrolyte is 10 to 20 mol / L.

8. The method for preparing an electrolyte for an aqueous zinc ion battery according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing a first additive, a second additive, a zinc salt and water.

9. An aqueous zinc ion battery, characterized in that: The invention comprises an electrolyte for an aqueous zinc ion battery as claimed in any one of claims 1 to 7.

10. An electrical device, characterized in that: Comprising the aqueous zinc ion battery as claimed in claim 9.