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CN-122025860-A - Natural product-based aqueous zinc ion battery electrolyte

CN122025860ACN 122025860 ACN122025860 ACN 122025860ACN-122025860-A

Abstract

The invention discloses a natural product-based aqueous zinc ion battery electrolyte which comprises water, soluble zinc salt and an additive, wherein the additive consists of N, N, N-trimethylglycine and any one of arginine, phenylalanine, glycine and valine. According to the invention, specific amino acid and N, N, N-trimethylglycine are compounded, and the specific amino acid and the N, N, N-trimethylglycine are synergistic, so that the solvation structure of Zn 2+ can be effectively regulated, protons in the electrolyte are neutralized, and the local pH value is increased, thereby forming a stable and uniform solid electrolyte interface film on the surface of a zinc cathode. The interfacial film can obviously inhibit hydrogen evolution side reaction and zinc dendrite growth, realizes multiple synergistic effects of adsorption guide nucleation, electrostatic shielding and pH adjustment, obviously improves the deposition/dissolution reversibility of a zinc cathode, greatly prolongs the cycle life, coulomb efficiency and safety performance of a water-based zinc ion battery, and the used additives are natural product derivatives, are environment-friendly and have good application prospects.

Inventors

  • BIAN HONGTAO
  • WANG MENGYU
  • PENG JIAHUI
  • JIANG HAN

Assignees

  • 陕西师范大学

Dates

Publication Date
20260512
Application Date
20260309

Claims (8)

  1. 1. The water-based zinc ion battery electrolyte based on the natural product is characterized by comprising water, zinc tetrafluoroborate and an additive, wherein the additive consists of amino acid and N, N, N-trimethylglycine according to the mass ratio of 1:0.5-35, and the amino acid is selected from any one of arginine, phenylalanine, glycine and valine.
  2. 2. The natural product-based aqueous zinc ion battery electrolyte according to claim 1, wherein the additive consists of amino acid and N, N, N-trimethylglycine in a mass ratio of 1:1-10.
  3. 3. The natural product-based aqueous zinc ion battery electrolyte according to claim 1, wherein the concentration of zinc tetrafluoroborate in the electrolyte is 0.5-3 mol/L.
  4. 4. The natural product-based aqueous zinc ion battery electrolyte according to claim 3, wherein the concentration of zinc tetrafluoroborate in the electrolyte is 1-1.5 mol/L.
  5. 5. The natural product-based aqueous zinc ion battery electrolyte according to claim 1, wherein the concentration of N, N, N-trimethylglycine in the electrolyte is 0.5-5 mol/L.
  6. 6. The natural product-based aqueous zinc ion battery electrolyte according to claim 5, wherein the concentration of N, N, N-trimethylglycine in the electrolyte is 1-3 mol/L.
  7. 7. The aqueous zinc-ion battery electrolyte according to claim 1, wherein the concentration of the amino acid in the electrolyte is 0.02-3 mol/L.
  8. 8. The aqueous zinc-ion battery electrolyte according to claim 7, wherein the concentration of the amino acid in the electrolyte is 0.03-1.0 mol/L.

Description

Natural product-based aqueous zinc ion battery electrolyte Technical Field The invention belongs to the technical field of zinc ion batteries, and relates to a water-based zinc ion battery electrolyte. Background In recent years, zinc tetrafluoroborate (Zn (BF 4)2) is widely paid attention to as a novel aqueous zinc ion battery electrolyte salt, compared with a traditional zinc sulfate or zinc chloride system, zn (BF 4- anions in BF 4)2 have stronger solvent structure regulating capability, can weaken an inter-water-molecule hydrogen bond network and improve a solvation structure of Zn 2+ to a certain extent, thereby being beneficial to regulating zinc deposition behavior. However, zn (BF 4)2 has a certain hydrolysis tendency in aqueous solution, acidic substances can be generated, and the pH value of electrolyte is reduced, so that corrosion of zinc cathode and hydrogen evolution side reaction are aggravated. To improve the above problems, there have been studies on the introduction of a single organic molecule (such as amino acid) or inorganic ion as an electrolyte additive to adjust the interfacial chemical environment or improve zinc deposition behavior. However, these single additives are often optimized only for a single problem in zinc dendrite growth or hydrogen evolution reaction, and when dealing with the problem of continuous acidification of interfaces caused by hydrolysis specific to a Zn (BF 4)2 system, multiple synergistic effects of adsorption guiding, pH buffering and interface stabilization are difficult to achieve. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a water-based zinc ion battery electrolyte based on natural products, so as to solve the problems of easy hydrolysis, easy hydrogen evolution and serious zinc dendrite growth of a zinc tetrafluoroborate system and realize the high-stability long-cycle operation of the water-based zinc ion battery. In order to achieve the purpose, the aqueous zinc ion battery electrolyte provided by the invention comprises water, zinc tetrafluoroborate and an additive, wherein the additive consists of amino acid and N, N, N-trimethylglycine according to the mass ratio of 1:0.5-35, and the amino acid is selected from any one of arginine, phenylalanine, glycine and valine. Further, the additive consists of amino acid and N, N, N-trimethylglycine according to the mass ratio of 1:1-10. Further, the concentration of zinc tetrafluoroborate in the electrolyte is 0.5-3 mol/L, preferably 1-1.5 mol/L. Further, the concentration of N, N, N-trimethylglycine in the electrolyte is 0.5-5 mol/L, preferably 1-3 mol/L. Further, the concentration of the amino acid in the electrolyte is 0.02-3 mol/L, preferably 0.03-1.0 mol/L. Compared with the prior art, the invention has the following remarkable beneficial effects: The electrolyte provided by the invention is used as an additive by compounding N, N, N-trimethylglycine and amino acid (arginine or phenylalanine or glycine or valine). The amino acid can be preferentially adsorbed on the surface of a zinc cathode by virtue of a unique amino and carboxyl structure, a solvation shell layer of zinc ions is regulated and is guided to be uniformly deposited, and N, N, N-trimethylglycine is used as an alkaloid, so that protons generated by hydrolysis of zinc tetrafluoroborate can be effectively neutralized, the local pH value of an electrode interface is improved, and the hydrogen evolution side reaction is inhibited. More importantly, the two have obvious synergistic effect, namely, the pH buffering effect of the N, N, N-trimethylglycine on the adsorption layer formed by the amino acid on the surface of the electrode provides a stable interface microenvironment, and the neutralization effect of the N, N-trimethylglycine on the proton also avoids the damage of the acidic environment to the amino acid adsorption layer, so that a layer of more stable and uniform solid electrolyte interface film is formed on the surface of the zinc cathode. The interface film can effectively prevent the electrolyte from directly contacting with the zinc cathode, reduce side reaction and promote the rapid conduction of zinc ions. Experimental results show that the Zn symmetric battery adopting the electrolyte provided by the invention can realize stable circulation exceeding 100 h under the current density of 10 mA cm -2, is far superior to a blank group without an additive and a control group with only a single component, has obviously reduced charge transfer impedance after circulation, and has higher redox reversibility and current response. The invention realizes multiple effects of adsorption guide nucleation, interface pH adjustment and electrostatic shielding through the synergistic effect of amino acid and N, N, N-trimethylglycine, remarkably improves the deposition/dissolution behavior of the zinc cathode, and greatly improves the cycle life, coulomb efficiency and safety performance of t