Energy Storage Science and Technology ›› 2022, Vol. 11 ›› Issue (4): 1103-1109.doi: 10.19799/j.cnki.2095-4239.2021.0694

• Special issue of International Outstanding Young Scientists for Energy Storage • Previous Articles     Next Articles

Stabilization of sodium metal anodes by dual-salt high concentration electrolyte

Ying TAO1(), Lingfei ZHAO1, Yunxiao WANG1(), Yuliang CAO2(), Shulei CHOU3()   

  1. 1.Institute for Superconducting & Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, Wollongong 2522, New South Wales, Australia
    2.College of Chemistry and Molecular Sciences, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University, Wuhan 430072, Hubei, China
    3.Institute for Carbon Neutralization, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, Zhejiang, China
  • Received:2021-12-21 Revised:2022-01-02 Online:2022-04-05 Published:2022-04-11
  • Contact: Yunxiao WANG,Yuliang CAO,Shulei CHOU E-mail:yt574@uowmail.edu.au;yunxiao@uow.edu.au;ylcao@whu.edu.cn;chou@wzu.edu.cn

Abstract:

Sodium (Na) metal has been regarded as a promising anode candidate for next-generation batteries with high energy density and power density. The Na metal anode, however, suffers from poor cycling stability and safety hazards associated with Na dendrite growth. To enhance cycling stability, sodium bis(fluorosulfonyl)imide (NaFSI) and sodium trifluoromethanesulfonimide (NaTFSI) were tested as a mixed dual salt in a series of high-concentration electrolytes, with diglyme (G2) as solvent. A NaFSI-NaTFSI high-concentration electrolyte considerably enhanced the cycling stability of Na metal anodes compared with single-salt electrolytes. Electrochemical performance and morphologies of the cycled Na metal anode indicate that the high-concentration dual-salt electrolyte could inhibit corrosion of the current collector and generate stable interfaces on the anodes. Na metal full cells coupled with a Na3V2(PO4)2F3 (NVPF) cathode in the optimal dual-salt high-concentration electrolyte have also been realized with stable cycling. This demonstrates the feasibility of this approach for practical applications in sodium metal batteries.

Key words: dual salt, high-concentration, electrolyte, Na metal anode, sodium metal batteries

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