Search

CN-121983680-A - Use of bifunctional zwitterionic additives in dual-phase zinc-halogen batteries

CN121983680ACN 121983680 ACN121983680 ACN 121983680ACN-121983680-A

Abstract

The application discloses an application of a difunctional zwitterionic additive in a biphasic zinc-halogen (comprising zinc-bromine and zinc-iodine) battery, wherein the molecular structural general formula of the zwitterionic additive is [ cation head group ] - [ connecting chain ] - [ anion head group ]. The problem that the shuttle inhibition of polybromides and the electrode reaction kinetics are difficult to be compatible and the stability of a zinc cathode is insufficient in the existing dual-phase zinc-halogen battery can be effectively solved by adding the zwitterionic additive into the dual-phase zinc-halogen battery electrolyte.

Inventors

  • YAN XINGBIN
  • LIU YILANG
  • DOU QINGYUN

Assignees

  • 中山大学

Dates

Publication Date
20260505
Application Date
20260115

Claims (10)

  1. 1. The application of the zwitterionic additive in the biphasic zinc-halogen (comprising zinc-bromine and zinc-iodine) battery electrolyte is characterized in that the molecular structural general formula of the zwitterionic additive is [ cation head group ] - [ connecting chain ] - [ anion head group ], the cation head group is selected from at least one of imidazolium, pyridinium, piperidinium and quaternary ammonium salt, the anion head group is selected from at least one of sulfonate, carboxylate, borate and phosphate, and the connecting chain is a C2-C10 alkyl chain or polyether chain.
  2. 2. Use according to claim 1, characterized in that the zwitterionic additive is selected from the following compounds: 1-butylsulfonic acid-3-ethylimidazolium (1-butylsulfonate-3-ethylimidazolium, imS); 3- (ethyldimethylammonium) propane-1-sulfonic acid inner salt (3- (ethyldimethylammonium) propane-1-sulfonic acid, EDPS); L-carnitine (L-CARNITINE, L-Car).
  3. 3. A biphasic zinc-halogen battery electrolyte, wherein the electrolyte comprises an aqueous phase, an organic phase, the zwitterionic additive according to claim 1 or 2 and an electrolyte.
  4. 4. A dual phase zinc-halogen battery electrolyte according to claim 3, characterized in that the molar concentration of the zwitterionic additive in the electrolyte is 0.001M to 0.5M, preferably 0.01 to 0.1M.
  5. 5. The biphasic zinc-halogen cell electrolyte of claim 3 wherein the organic phase is selected from at least one of tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, succinonitrile, propylene carbonate, ethylene carbonate, dimethyl carbonate, N-dimethylacetamide, N-dimethylformamide, ethyl acetate.
  6. 6. The dual phase zinc-halogen battery electrolyte according to claim 3, characterized in that the electrolyte is selected from ZnBr 2 and ZnI 2 , with a molar concentration of 0.2 to 1.5M.
  7. 7. The dual phase zinc-halogen battery electrolyte of claim 3 further comprising a sulfate salt selected from at least one of lithium sulfate, sodium sulfate, potassium sulfate, zinc sulfate, copper sulfate, magnesium sulfate, aluminum sulfate, at a molar concentration of 0.5 to 1.5M.
  8. 8. The dual phase zinc-halogen cell electrolyte of claim 3 in which the volume ratio of the aqueous phase to the organic phase is 1:4 to 4:1.
  9. 9. A biphasic zinc-halogen cell, characterized in that it comprises a negative electrode immersed in the aqueous phase of the electrolyte, a positive electrode immersed in the organic phase of the electrolyte, and an electrolyte according to any one of claims 3 to 8.
  10. 10. The biphasic zinc-halogen cell according to claim 9, characterized in that the negative electrode is preferably selected from zinc sheets, zinc foils, zinc blocks and various substances composited with zinc metal; Preferably, the positive electrode current collector is a carbon material or a carbon-based composite material, and is specifically selected from graphite felt, carbon cloth, conductive carbon paper and the like.

Description

Use of bifunctional zwitterionic additives in dual-phase zinc-halogen batteries Technical Field The application belongs to the technical field of electrochemical energy storage and batteries, and particularly relates to application of a difunctional zwitterionic additive in a biphasic zinc-halogen (comprising zinc-bromine and zinc-iodine) battery. Background The zinc-halogen battery, in particular to a zinc-bromine battery and a zinc-iodine battery, has the advantages of high theoretical voltage, low raw material cost, high safety and the like, and has great application potential in the field of large-scale long-term energy storage. However, the commercialization process is limited by a key bottleneck in that soluble polyhalides (such as Br 3-,I3-) generated during charging can shuttle from the positive side to the zinc negative electrode, causing severe self-discharge, zinc corrosion and capacity fade. In order to inhibit polyhalide shuttling, researchers in chinese patent application number 2023116980386 have proposed a biphasic electrolyte strategy that uses the immiscibility of the aqueous phase and the organic solvent phase to confine polyhalides to the higher solubility organic phase and achieve physical space isolation. However, the existing biphasic system still has two major problems that firstly, the effect of static physical limitation is limited under high-concentration polyhalide or long-term circulation, and the shuttle phenomenon still occurs, and secondly, biphasic design has contradiction in optimizing the reaction kinetics and interface stability of the electrode, namely, the electrolyte designed for strengthening the limitation usually sacrifices the positive reaction rate, and the components beneficial to the kinetics exacerbate the side reaction of the zinc cathode. Electrolyte additives are effective means for regulating the chemical environment inside the battery and solving the above problems. Currently, there is a lack of a multifunctional additive for dual-phase zinc-halogen cells that can function in both phases simultaneously, synergistically inhibit polyhalide shuttling and stabilize zinc cathodes. In view of the above-mentioned shortcomings of the prior art, the inventors of the present application have found that the problems of both the multi-bromide shuttle inhibition and the electrode reaction kinetics in the existing dual-phase zinc-halogen battery and the insufficient stability of the zinc negative electrode can be effectively solved by adding the zwitterionic additive to the dual-phase zinc-halogen battery electrolyte. According to a first aspect of the application, the application of the zwitterionic additive in a biphasic zinc-halogen (including zinc-bromine and zinc-iodine) battery electrolyte is provided, wherein the molecular structural general formula of the zwitterionic additive is [ cation head group ] - [ connecting chain ] - [ anion head group ], the cation head group is selected from at least one of imidazolium, pyridinium, piperidinium and quaternary ammonium salt, the anion head group is selected from at least one of sulfonate, carboxylate, borate and phosphate, and the connecting chain is a C2-C10 alkyl chain or polyether chain. Preferably, the zwitterionic additive is selected from the following compounds: 1-Butylsulfonic acid-3-ethylimidazolium (1-butylsulfonate-3-ethylimidazolium, imS) 3- (Ethyldimethylammonium) propane-1-sulfonic acid inner salt (3- (ethyldimethylammonium) propane-1-sulfonic acid, EDPS) L-carnitine (L-CARNITINE, L-Car). According to a second aspect of the present application there is provided a dual phase zinc-halogen battery electrolyte comprising an aqueous phase, an organic phase, the zwitterionic additive and an electrolyte. Preferably, the molar concentration of the zwitterionic additive in the electrolyte is from 0.001M to 0.5M, preferably from 0.01 to 0.1M. Preferably, the organic phase in the electrolyte is at least one selected from tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, succinonitrile, propylene carbonate, ethylene carbonate, dimethyl carbonate, N-dimethylacetamide, N-dimethylformamide, and ethyl acetate. Preferably, the electrolyte in the electrolyte is selected from ZnBr 2 and ZnI 2, with a molar concentration of 0.2 to 1.5M. Further preferably, the electrolyte further comprises a sulfate selected from at least one of lithium sulfate, sodium sulfate, potassium sulfate, zinc sulfate, copper sulfate, magnesium sulfate, aluminum sulfate, and has a molar concentration of 0.5 to 1.5M. Preferably, the volume ratio of the aqueous phase and the organic phase in the electrolyte is 1:4 to 4:1. According to a third aspect of the present application there is provided a dual phase zinc-halogen battery comprising a negative electrode, a positive electrode and an electrolyte as described above. Wherein, the negative electrode is immersed in the water phase of the electrolyte,