Amphiphilic difunctional aqueous electrolyte additive based on imide, preparation method and application

Abstract

The invention provides an imide-based amphiphilic bifunctional aqueous electrolyte additive, which consists of amphiphilic imide anions and functional metal ions, can be applied to an aqueous zinc ion battery, and can be used for preparing an aqueous zinc ion battery by reacting an aqueous solution of an imide substance with different non-zinc metal sources. And drying to obtain the amphiphilic bifunctional electrolyte additive. The positive ions in the additive not only can optimize the current density of the surface of the zinc negative electrode by utilizing an electrostatic shielding effect, but also can participate in solvation of zinc ions, so that the interaction between sulfate radicals and the zinc ions is weakened, and the side reaction between metal zinc and electrolyte is inhibited. An electrochemical performance test shows that the cycle performance of the battery can be obviously improved by adding a small amount of the additive into the traditional aqueous electrolyte. The additive is simple in preparation method, low in cost and high in generalizability and has important practical significance.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolyte additives, and particularly relates to an amphiphilic bifunctional aqueous electrolyte additive based on imide, a preparation method and an application thereof. Background Art

[0002] In order to promote the green and low-carbon transformation and sustainable development of the economic society, and actively and steadily advance the goals of carbon peak and carbon neutrality, the proportion of renewable energy (solar energy, wind energy, tidal energy, geothermal energy, etc.) and nuclear power generation in the total power generation in China has been increasing year by year. However, at present, the energy conversion power of renewable energy is relatively low and the volatility is relatively large, so it cannot be directly incorporated into the power grid. As a common electrochemical device, secondary batteries have great application prospects in large-scale energy storage. However, the currently relatively mature lithium-ion batteries have problems such as being flammable, explosive and high cost, which restricts the use of lithium-ion batteries in the energy storage field. Therefore, developing a low-cost and high-safety energy storage device is of great significance for promoting the application of renewable energy.

[0003] Aqueous zinc-ion batteries have high application prospects in fixed energy storage solutions due to their low cost, high safety and environmental friendliness. However, in traditional weakly acidic aqueous solutions (such as 2 mol / L zinc sulfate), due to the randomness of metal zinc electrodeposition and the poor chemical / electrochemical stability of metal zinc, serious dendrites and corrosion will occur during the use of aqueous zinc-ion batteries, resulting in poor battery cycle life and serious gas production. Therefore, it is crucial to develop a simple, practical and popularizable strategy to achieve an aqueous zinc-ion battery with excellent cycle stability.

[0004] Based on this, the present application provides an amphiphilic bifunctional aqueous electrolyte additive based on imide and a preparation method thereof. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides an aqueous electrolyte additive composed of amphiphilic imide anions and functionalized metal ions, and the used electrolyte additive can be directly prepared from a modified imide matrix and a functionalized metal ion source. In this electrolyte additive, the functionalized metal ions and amphiphilic imide anions cooperate to regulate the main exposed crystal plane of the zinc coating and improve the corrosion resistance of the zinc negative electrode in the electrolyte, and can effectively improve the electrochemical performance of the aqueous zinc-ion battery in the electrolyte.

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

[0007] In the first aspect, the present invention provides an amphiphilic bifunctional aqueous electrolyte additive based on imide, which is composed of amphiphilic imide anions and functionalized metal ions.

[0008] Furthermore, the imide precursor is R 1 -SO 2 -NH-SO 2 -R 2 or R 1 -CO-NH-CO-R 2 , where R 1 Including any one of alkyl, benzene ring, halogen, amino, R 2 It includes any one of an alkyl group, a benzene ring, a halogen group, and an amino group.

[0009] Furthermore, the raw material of the functionalized metal ion is a non-zinc metal or metal compound.

[0010] Furthermore, the raw material of the functionalized metal ions includes any one of magnesium hydroxide, chromium trioxide, aluminum hydroxide, copper oxide, gallium trioxide, iron hydroxide and calcium hydroxide.

[0011] In a second aspect, the present invention further provides a method for preparing an imide-based amphiphilic bifunctional aqueous electrolyte additive, the steps comprising:

[0012] (1) dissolving an amphiphilic imide organic compound in deionized water, adding a functionalized metal ion source, and reacting the mixture sufficiently;

[0013] (2) Removing the excess metal ion source by centrifugation, stirring the centrifuged solution for 4 hours, and then drying to remove all moisture, thereby obtaining a bifunctional electrolyte additive.

[0014] Furthermore, the amphiphilic imide organic compound includes bisbenzenesulfonimide (imide parent is R 1 -SO 2 -NH-SO 2 -R 2 , where R 1 and R 2 are all benzene rings), succinimide (imide parent is R 1 -CO-NH-CO-R 2 , wherein R1 and R2 are methyl groups, and the two methyl groups are connected) and phthalimide (imide parent is R 1 -CO-NH-CO-R 2 , where R 1 and R 2 is the same benzene ring).

[0015] Furthermore, the reaction temperature is 40-100° C., and the reaction time is 10-50 h.

[0016] Furthermore, the reaction temperature is 80° C. and the reaction time is 24 h.

[0017] Further, the molar ratio of the amphiphilic imide-based organic compound to the functionalized metal ion source is not greater than 3. ， The amount of the solvent added is only required to ensure the dissolution of the amphiphilic imide-based organic compound.

[0018] Further, when the metal ion is a divalent ion, the molar ratio of the amphiphilic imide-based organic compound to the functionalized metal ion source is 2:1.1; when the metal ion is a trivalent ion, the molar ratio of the amphiphilic imide-based organic compound to the functionalized metal ion source is 3:1.1.

[0019] In a third aspect, the present invention relates to the application of the amphiphilic bifunctional aqueous electrolyte additive based on imide in the preparation of an aqueous zinc ion battery electrolyte, and the usage amount of the additive is 0.01 - 0.5 mol / L.

[0020] Further, the preparation method of the electrolyte includes: adding the prepared amphiphilic bifunctional aqueous electrolyte additive based on imide to a commercial traditional aqueous electrolyte at different concentrations (0.01 - 0.5 mol / L), and the final electrolyte for use can be obtained. The commercial traditional aqueous electrolyte includes commercial 2 mol / L ZnSO 4 electrolyte.

[0021] When used as the only additive in the preparation of an aqueous zinc ion battery electrolyte, this amphiphilic bifunctional aqueous electrolyte additive based on imide can not only achieve a zinc coating with a single crystal plane exposed, but also inhibit the corrosion reaction of metallic zinc.

[0022] The advantages of the present invention are as follows: By adding such a small amount of the electrolyte additive to the traditional electrolyte additive zinc sulfate, the generation of side reactions is reduced compared with using only zinc sulfate electrolyte, thereby improving the electrochemical performance of the battery. The reason is that the amphiphilic imide anions in the electrolyte additive can adsorb on the (001) and (101) planes of metallic zinc, thereby masking the deposition / stripping of metallic zinc on the above two crystal planes, enabling zinc ions in the electrolyte to deposit regularly on the (002) plane, because this plane has a stronger ability to inhibit dendrite growth and side reactions. Moreover, the bifunctional cations in the additive can utilize their electrostatic shielding effect to optimize the current density on the surface of the zinc negative electrode, and can also participate in the solvation of zinc ions, converting the solvation structure of zinc ions from CIP to SSIP, weakening the interaction between sulfate ions and zinc ions, and inhibiting the side reaction between metallic zinc and the electrolyte, thereby improving the electrochemical performance of the aqueous zinc ion battery.

[0023] The electrolyte additive prepared by the present invention has the characteristics of dual function, low dosage and easy popularization. Due to the special hydrophilic-hydrophobic structure of this electrolyte additive, its anions can be highly selectively adsorbed on the (001) and (101) planes of metallic zinc, thereby masking the deposition / stripping of metallic zinc on the above two crystal planes and forming a flat zinc coating with a single (002) crystal plane exposed. In addition, the cations in the additive can not only optimize the current density on the surface of the zinc negative electrode by using the electrostatic shielding effect, but also participate in the solvation of zinc ions, weaken the interaction between sulfate ions and zinc ions, and inhibit the side reaction between metallic zinc and the electrolyte. Under the conditions of a current density of 1 mA cm -2 and a areal capacity of 1 mAh cm -2 , using an aqueous solution of 2 mol / L zinc sulfate as the electrolyte and adding 0.02 mol / L of the electrolyte additive, the zinc-zinc symmetric battery can achieve repeated cycling for more than 4000 h without short circuit, and its cycle life far exceeds that of the zinc-zinc symmetric battery assembled with a 2 mol / L zinc sulfate electrolyte. In summary, the electrolyte additive prepared by the present invention can solve the problems of dendrites and side reactions in aqueous zinc-ion batteries and obtain excellent electrochemical performance. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Digital photo of the dual-functional electrolyte additive obtained in Example 1;

[0026] Figure 2 Cycling performance of the zinc-zinc symmetric battery in the electrolyte obtained in Example 1;

[0027] Figure 3 Cycling performance of the zinc-zinc symmetric battery in the electrolyte obtained in Comparative Example 1;

[0028] Figure 4 Scanning electron microscope photo of the zinc electrode after cycling of the zinc-zinc symmetric battery in the electrolyte obtained in Example 1;

[0029] Figure 5 Scanning electron microscope photo of the zinc electrode after cycling of the zinc-zinc symmetric battery in the electrolyte obtained in Comparative Example 1. Detailed Description of the Embodiments

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The invention discloses an amphiphilic bifunctional aqueous electrolyte additive based on imide, which is composed of an amphiphilic imide anion and a functionalized metal ion, wherein the amphiphilic imide anion can induce a zinc coating with a single (002) crystal plane exposed, and the functionalized metal ion can inhibit the corrosion reaction of metallic zinc.

[0032] In a further embodiment, the imide precursor is R 1 -SO 2 -NH-SO 2 -R 2 or R 1 -CO-NH-CO-R 2 , where R 1 Including any one of alkyl, benzene ring, halogen, amino, R 2 Including any one of alkyl, benzene ring, halogen, amino group; the raw material of the functionalized metal ion is non-zinc metal or metal compound; the raw material of the functionalized metal ion includes any one of magnesium hydroxide, chromium trioxide, iron hydroxide and calcium hydroxide;

[0033] The preparation steps include:

[0034] (1) dissolving an amphiphilic imide organic compound in deionized water, adding an excess amount of a functionalized metal ion source, and reacting the mixture sufficiently;

[0035] (2) Removing the excess metal ion source by centrifugation, stirring the centrifuged solution for 4 hours, and then drying to remove all moisture, thereby obtaining a bifunctional electrolyte additive.

[0036] In a further embodiment, the amphiphilic imide organic compound comprises bisbenzenesulfonimide (imide parent is R 1 -SO 2 -NH-SO 2 -R 2 , where R 1 and R 2 are all benzene rings), succinimide (imide parent is R 1 -CO-NH-CO-R 2 , wherein R1 and R2 are methyl groups, and the two methyl groups are connected) and phthalimide (imide parent is R1 -CO-NH-CO-R 2 , wherein R 1 and R 2 is any one of the same benzene ring); the reaction temperature is 0 - 100 °C, the reaction time is 0.5 - 72 h, and the optimal conditions are a reaction temperature of 80 °C and a reaction time of 24 h; the molar ratio of the amphiphilic imide organic compound to the functionalized metal ion source is not greater than 3 ， The amount of the solvent added is such that the amphiphilic imide organic compound can be dissolved.

[0037] In a further embodiment, when the metal ion is a divalent ion, the molar ratio of the amphiphilic imide organic compound to the functionalized metal ion source is 2:1.1; when the metal ion is a trivalent ion, the molar ratio of the amphiphilic imide organic compound to the functionalized metal ion source is 3:1.1.

[0038] The amphiphilic bifunctional aqueous electrolyte additive based on imide in the present invention is applied to the preparation of an aqueous zinc ion battery electrolyte, and the usage amount of the additive is 0.01 - 0.5 mol / L.

[0039] In a further embodiment, the preparation method of the electrolyte includes: adding the prepared amphiphilic bifunctional aqueous electrolyte additive based on imide to a commercial traditional aqueous electrolyte at different concentrations (0.01 - 0.5 mol / L), and the final used electrolyte can be obtained. The commercial traditional aqueous electrolyte includes a commercial 2 mol / L ZnSO 4 electrolyte.

[0040] The test materials and reagents used in the following examples, unless otherwise specified, can all be obtained from commercial channels. For those not specified in the examples regarding specific technologies or conditions, they can all be carried out according to the technologies or conditions described in the literature in the field or according to the product specifications.

[0041] Example 1

[0042] An aqueous electrolyte added with an amphiphilic bifunctional additive, including a traditional electrolyte, an amphiphilic anion, and a functionalized metal cation, is prepared by the following steps:

[0043] (1) Weigh 0.02 mol of bis(phenylsulfonyl)imide in a beaker, add 50 mL of deionized water, and stir to dissolve;

[0044] (2) Add 0.015 mol of magnesium hydroxide to the solution prepared in step (1), and heat and react at 80 °C for 24 h;

[0045] (3) Use a centrifuge to centrifuge the solution obtained in step (2) at a centrifugation speed of 9000 r / min for 3 min to remove unreacted magnesium hydroxide. Stir the centrifuged solution with a magnetic stirrer at a speed of 100 r / min for about 4 hours, and then place it in a vacuum dryer at 100 °C for drying for 4 h to remove all moisture, obtaining a magnesium ion-containing bifunctional electrolyte additive;

[0046] The digital photo of the obtained magnesium ion-containing bifunctional electrolyte additive (magnesium bis(phenylsulfonyl)imide) is as Figure 1 shown.

[0047] (4) Weigh 1.19 g of the magnesium salt prepared in step (3) and 32.29 g of zinc sulfate and put them into a beaker, and add 100 mL of deionized water to obtain the finally used electrolyte, which is 2 mol / L zinc sulfate plus 0.02 mol / L magnesium bis(phenylsulfonyl)imide.

[0048] Using the electrolyte additive obtained in step (4), assemble a 2032-type button zinc-zinc symmetric battery with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm). At a current density of 1 mA cm -2 and areal capacity of 1 mAh cm -2 , perform repeated constant current charge-discharge cycles on the battery. The results are as Figure 2 shown.

[0049] From Figure 2 , it can be seen that the battery has been cycled for more than 4000 h without short circuit. The scanning electron microscope photo of the zinc electrode after cycling is as Figure 4 shown, and it can be seen that the coating is composed of hexagonal (002) crystal planes.

[0050] Example 2

[0051] An aqueous electrolyte added with an amphiphilic bifunctional additive, comprising a traditional electrolyte, an amphiphilic anion and a functionalized metal cation, is prepared by the following steps:

[0052] (1) Weigh 0.02 mol of succinimide in a beaker, add 50 mL of deionized water, and stir to dissolve;

[0053] (2) Add 0.015 mol of magnesium hydroxide to the solution prepared in step (1), and heat and react at 80 °C for 24 h;

[0054] (3) Use a centrifuge to centrifuge the solution obtained in step (2) at a centrifugation speed of 9000 r / min for 3 min to remove unreacted magnesium hydroxide. Stir the centrifuged solution with a magnetic stirrer at a speed of 100 r / min for about 4 hours, and then place it in a vacuum dryer at 100 °C for drying for 4 h to remove all moisture, obtaining a magnesium ion-containing bifunctional electrolyte additive;

[0055] (4) Weigh 0.44 g of the magnesium salt prepared in step (3) and 32.29 g of zinc sulfate into a beaker and add 100 mL of deionized water to obtain the finally used electrolyte, which is 2 mol / L zinc sulfate plus 0.02 mol / L magnesium succinimide.

[0056] Using the electrolyte additive obtained in step (4), assemble a 2032-type button zinc-zinc symmetric battery with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm), and perform repeated constant current charge and discharge cycles on the battery under the conditions of a current density of 1 mA cm -2 、areal capacity of 1 mAh cm -2 .

[0057] Example 3

[0058] An aqueous electrolyte added with an amphiphilic bifunctional additive, comprising a traditional electrolyte, an amphiphilic anion, and a functionalized metal cation, is prepared by the following steps:

[0059] (1) Weigh 0.02 mol of phthalimide into a beaker, add 50 mL of deionized water, and stir to dissolve;

[0060] (2) Add 0.015 mol of magnesium hydroxide to the solution prepared in step (1), and heat and react at 80 °C for 24 h;

[0061] (3) Use a centrifuge to centrifuge the solution obtained in step (2) at a centrifugation speed of 9000 r / min for 3 min to remove unreacted magnesium hydroxide. Stir the centrifuged solution with a magnetic stirrer at a speed of 100 r / min for about 4 hours, and then place it in a vacuum dryer at 100 °C for drying for 4 h to remove all moisture, obtaining a magnesium ion-containing bifunctional electrolyte additive;

[0062] (4) Weigh 0.63 g of the magnesium salt prepared in step (3) and 32.29 g of zinc sulfate into a beaker and add 100 mL of deionized water to obtain the finally used electrolyte, which is 2 mol / L zinc sulfate plus 0.02 mol / L magnesium phthalimide.

[0063] Using the electrolyte additive obtained in step (4), a 2032-type button zinc-zinc symmetric battery was assembled with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm), and the battery was subjected to repeated constant current charge-discharge cycles under the conditions of a current density of 1 mA cm-2 and an areal capacity of 1 mAh cm-2.

[0064] Example 4

[0065] An aqueous electrolyte added with an amphiphilic bifunctional additive, including a traditional electrolyte, an amphiphilic anion, and a functionalized metal cation, is prepared by the following steps:

[0066] (1) Weigh 0.03 mol of bis(phenylsulfonyl)imide into a beaker, add 50 mL of deionized water, and stir to dissolve.

[0067] (2) Add 0.011 mol of chromium(III) oxide to the solution prepared in step (1), and heat and react at 80 °C for 24 h.

[0068] (3) Use a centrifuge to centrifuge the solution obtained in step (2) at a centrifugal speed of 9000 r / min for 3 min to remove unreacted magnesium hydroxide. Stir the centrifuged solution with a magnetic stirrer at a speed of 100 r / min for about 4 hours, and then place it in a vacuum dryer at 100 °C for 4 h to remove all moisture, obtaining a magnesium ion-containing bifunctional electrolyte additive;

[0069] (4) Weigh 1.88 g of the chromium salt prepared in step (3) and 32.29 g of zinc sulfate into a beaker and add 100 mL of deionized water to obtain the finally used electrolyte, which is 2 mol / L zinc sulfate plus 0.02 mol / L bis(phenylsulfonyl)imide chromium.

[0070] Using the electrolyte additive obtained in step (4), a 2032-type button zinc-zinc symmetric battery was assembled with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm), at a current density of 1 mA cm -2 and an areal capacity of 1 mAh cm -2 under the conditions, the battery was subjected to repeated constant current charge-discharge cycles.

[0071] Example 5

[0072] An aqueous electrolyte added with an amphiphilic bifunctional additive, including a traditional electrolyte, an amphiphilic anion, and a functionalized metal cation, is prepared by the following steps:

[0073] (1) Weigh 0.03 mol of bis(phenylsulfonyl)imide into a beaker, add 50 mL of deionized water, and stir to dissolve.

[0074] (2) Add 0.011 mol of iron hydroxide to the solution prepared in step (1), and heat and react at 80 °C for 24 h.

[0075] (3) Use a centrifuge to centrifuge the solution obtained in step (2) at a centrifugal speed of 9000 r / min for 3 min to remove unreacted magnesium hydroxide. Stir the centrifuged solution with a magnetic stirrer at a speed of 100 r / min for about 4 hours, and then place it in a vacuum dryer at 100 °C to dry for 4 h to remove all moisture, obtaining a magnesium ion-containing bifunctional electrolyte additive.

[0076] (4) Weigh 1.89 g of the iron salt prepared in step (3) and 32.29 g of zinc sulfate, put them into a beaker, and add 100 mL of deionized water to obtain the finally used electrolyte, which is 2 mol / L zinc sulfate plus 0.02 mol / L iron bis(phenylsulfonyl)imide.

[0077] Using the electrolyte additive obtained in step (4), assemble a 2032-type coin zinc-zinc symmetric battery with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm), and perform repeated constant current charge-discharge cycles on the battery under the conditions of a current density of 1 mA cm -2 and a areal capacity of 1 mAh cm -2 .

[0078] Example 6

[0079] An aqueous electrolyte added with an amphiphilic bifunctional additive, comprising a traditional electrolyte, an amphiphilic anion, and a functionalized metal cation, is prepared by the following steps:

[0080] (1) Weigh 0.02 mol of iron bis(phenylsulfonyl)imide into a beaker, add 50 mL of deionized water, and stir to dissolve.

[0081] (2) Add 0.015 mol of calcium hydroxide to the solution prepared in step (1), and heat and react at 80 °C for 24 h.

[0082] (3) Use a centrifuge to centrifuge the solution obtained in step (2) at a centrifugal speed of 9000 r / min for 3 min to remove unreacted magnesium hydroxide. Stir the centrifuged solution with a magnetic stirrer at a speed of 100 r / min for about 4 hours, and then place it in a vacuum dryer at 100 °C to dry for 4 h to remove all moisture, obtaining a magnesium ion-containing bifunctional electrolyte additive.

[0083] (4) Weigh 1.27 g of the calcium salt obtained in step (3) and 32.29 g of zinc sulfate, put them into a beaker, and add 100 mL of deionized water to obtain the finally used electrolyte, which is 2 mol / L zinc sulfate plus 0.02 mol / L calcium bis(phenylsulfonyl)imide.

[0084] Using the electrolyte additive obtained in step (4), assemble a 2032-type coin-type zinc-zinc symmetric battery with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm). At a current density of 1 mA cm -2 and areal capacity of 1 mAh cm -2 under the conditions, perform repeated constant current charge-discharge cycles on the battery.

[0085] Example 7

[0086] An aqueous electrolyte added with an amphiphilic bifunctional additive, including a traditional electrolyte, an amphiphilic anion, and a functionalized metal cation, is prepared by the following steps:

[0087] (1) Weigh 0.02 mol of bis(phenylsulfonyl)imide into a beaker, add 50 mL of deionized water, and stir to dissolve.

[0088] (2) Add 0.015 mol of magnesium hydroxide to the solution obtained in step (1), and heat and react at 80 °C for 24 h.

[0089] (3) Use a centrifuge to centrifuge the solution obtained in step (2) at a centrifugation speed of 9000 r / min for 3 min to remove the unreacted magnesium hydroxide. Stir the centrifuged solution with a magnetic stirrer at a speed of 100 r / min for about 4 hours, and then place it in a vacuum dryer at 110 °C for 4 h to remove all moisture to obtain a bifunctional electrolyte additive containing magnesium ions;

[0090] (4) Weigh 1.19 g of the magnesium salt obtained in step (3) and 32.29 g of zinc sulfate, put them into a beaker, and add 100 mL of deionized water to obtain the finally used electrolyte, which is 2 mol / L zinc sulfate plus 0.02 mol / L magnesium bis(phenylsulfonyl)imide.

[0091] Using the electrolyte additive obtained in step (4), assemble a 2032-type coin-type zinc-zinc symmetric battery with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm). At a current density of 1 mA cm -2 and areal capacity of 1 mAh cm -2 under the conditions, perform repeated constant current charge-discharge cycles on the battery.

[0092] Example 8

[0093] An aqueous electrolyte added with an amphiphilic bifunctional additive, comprising a traditional electrolyte, an amphiphilic anion and a functionalized metal cation, is prepared by the following steps:

[0094] (1) Weigh 0.02 mol of bis(phenylsulfonyl)imide into a beaker, add 50 mL of deionized water, and stir to dissolve.

[0095] (2) Add 0.015 mol of magnesium hydroxide to the solution prepared in step (1), and heat and react at 80 °C for 24 h.

[0096] (3) Use a centrifuge to centrifuge the solution obtained in step (2) at a centrifugation speed of 9000 r / min for 3 min to remove the unreacted magnesium hydroxide. Stir the centrifuged solution with a magnetic stirrer at a speed of 100 r / min for about 4 hours, and then place it in a vacuum dryer at 90 °C to dry for 4 h to remove all moisture, obtaining a bifunctional electrolyte additive containing magnesium ions.

[0097] (4) Weigh 1.19 g of the magnesium salt prepared in step (3) and 32.29 g of zinc sulfate into a beaker and add 100 mL of deionized water to obtain the finally used electrolyte, which is 2 mol / L zinc sulfate plus 0.02 mol / L magnesium bis(phenylsulfonyl)imide.

[0098] Using the electrolyte additive obtained in step (4), assemble a 2032-type button zinc-zinc symmetric battery with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm). At a current density of 1 mA cm -2 and an areal capacity of 1 mAh cm -2 , perform repeated constant current charge-discharge cycles on the battery.

[0099] Comparative Example 1

[0100] An aqueous zinc-ion battery electrolyte containing commercial zinc sulfate, comprising a solute zinc sulfate and a solvent water, is prepared by the following steps:

[0101] Directly prepare a 2 mol / L solution of commercial zinc sulfate, which is the electrolyte used in Comparative Example 1.

[0102] Using this electrolyte, without adding any electrolyte additives, assemble a 2032-type button zinc-zinc symmetric battery with a glass fiber separator (GF-A type) with a diameter of 19 mm and a zinc sheet with a diameter of 16 mm (thickness 100 μm). At a current density of 1 mA cm -2 and an areal capacity of 1 mAh cm -2 , perform repeated constant current charge-discharge cycles on the battery, and the results are as Figure 3The scanning electron microscope photograph of the zinc electrode after cycling is as shown in Figure 5 as shown.

[0103] The applicant declares that the present invention illustrates the products and detailed preparation methods of the present invention through the above embodiments, but the present invention is not limited to the above products and detailed preparation methods, that is, it does not mean that the present invention must rely on the above products and detailed preparation methods to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent substitution of each raw material of the products of the present invention and the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and the disclosure scope of the present invention.

[0104] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple deformations can be made to the technical solutions of the present invention. These simple deformations all belong to the protection scope of the present invention.

[0105] In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, they can be combined in any appropriate way without contradiction. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0106] In addition, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. An amphiphilic bifunctional aqueous electrolyte additive based on imide, characterized in that: It is composed of an affinic imide anion and a functionalized metal ion.

2. The imide-based amphiphilic bifunctional aqueous electrolyte additive according to claim 1, characterized in that: The imide matrix is ​​R1-SO2-NH-SO2-R2 or R1-CO-NH-CO-R2, wherein R1 includes any one of an alkyl group, a benzene ring, a halogen, and an amino group, and R2 includes any one of an alkyl group, a benzene ring, a halogen, and an amino group.

3. The imide-based amphiphilic bifunctional aqueous electrolyte additive according to claim 1, characterized in that: The raw material of the functionalized metal ion is non-zinc metal or metal compound.

4. The imide-based amphiphilic bifunctional aqueous electrolyte additive according to claim 3, characterized in that: The raw material of the functionalized metal ion includes any one of magnesium hydroxide, chromium trioxide, aluminum hydroxide, copper oxide, gallium trioxide, iron hydroxide and calcium hydroxide.

5. A method for preparing an imide-based amphiphilic bifunctional aqueous electrolyte additive as claimed in claims 1 to 3, characterized in that the steps include: (1) dissolving an amphiphilic imide organic compound in deionized water, adding a functionalized metal ion source, and reacting the mixture sufficiently; (2) Removing the excess metal ion source by centrifugation, stirring the centrifuged solution for 4 hours, and then drying to remove all moisture, thereby obtaining a bifunctional electrolyte additive.

6. The method for preparing an imide-based amphiphilic bifunctional aqueous electrolyte additive according to claim 4, characterized in that: The amphiphilic imide organic compound includes any one of bisbenzenesulfonimide, succinimide and phthalimide.

7. The method for preparing an imide-based amphiphilic bifunctional aqueous electrolyte additive according to claim 4, characterized in that: The reaction temperature is 40-100° C., and the reaction time is 10-50 h.

8. The method for preparing an imide-based amphiphilic bifunctional aqueous electrolyte additive according to claim 4, characterized in that: The molar ratio of the amphiphilic imide organic compound to the functionalized metal ion source is no more than 3.

9. Use of the imide-based amphiphilic bifunctional aqueous electrolyte additive as described in any one of claims 1 to 3 in the preparation of aqueous zinc ion battery electrolyte.

10. The use according to claim 9, characterized in that: The usage amount of the additive is 0.01-0.5 mol / L.

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