Co-Solvent Electrolyte Design to Inhibit Phase Transition toward High Performance K+ /Zn2+ Hybrid Battery

Wei Chen; Jiahao Wu; Kai Fu; Zhaohui Deng; Xingbao Chen; Hongwei Cai; Xinfei Wu; Boyu Xing; Wen Luo; Liqiang Mai

doi:10.1002/smtd.202300617

Co-Solvent Electrolyte Design to Inhibit Phase Transition toward High Performance K⁺ /Zn²⁺ Hybrid Battery

Small Methods. 2023 Jul 9:e2300617. doi: 10.1002/smtd.202300617. Online ahead of print.

Authors

Wei Chen¹, Jiahao Wu¹, Kai Fu¹, Zhaohui Deng¹, Xingbao Chen¹, Hongwei Cai¹, Xinfei Wu¹, Boyu Xing¹, Wen Luo^{1

2}, Liqiang Mai^{1

3}

Affiliations

¹ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, Hubei, 430070, P. R. China.
² Department of Physics, School of Science, Wuhan University of Technology, Wuhan, 430070, P. R. China.
³ Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Xianhu Hydrogen Valley, Foshan, 528200, P. R. China.

PMID: 37423947
DOI: 10.1002/smtd.202300617

Abstract

Manganese hexacyanoferrate (MnHCF) is one of the most promising cathode materials for aqueous battery because of its non-toxicity, high energy density, and low cost. But the phase transition from MnHCF to Zinc hexacyanoferrate (ZnHCF) and the larger Stokes radius of Zn²⁺ cause rapid capacity decay and poor rate performance in aqueous Zn battery. Hence, to overcome this challenge, a solvation structure of propylene carbonate (PC)-trifluoromethanesulfonate (Otf)-H₂ O is designed and constructed. A K⁺ /Zn²⁺ hybrid battery is prepared using MnHCF as cathode, zinc metal as anode, KOTf/Zn(OTf)₂ as the electrolyte, and PC as the co-solvent. It is revealed that the addition of PC inhabits the phase transition from MnHCF to ZnHCF, broaden the electrochemical stability window, and inhibits the dendrite growth of zinc metal. Hence, the MnHCF/Zn hybrid co-solvent battery exhibits a reversible capacity of 118 mAh g^-1 and high cycling performance, with a capacity retention of 65.6% after 1000 cycles with condition of 1 A g^-1 . This work highlights the significance of rationally designing the solvation structure of the electrolyte and promotes the development of high-energy-density of aqueous hybrid ion batteries.

Keywords: MnHCF; aqueous hybrid batteries; co-solvents; electrolyte solvation structure; phase transition.

Abstract

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