High-Energy Rechargeable Metallic Lithium Battery at -70 °C Enabled by a Cosolvent Electrolyte

Xiaoli Dong; Yuxiao Lin; Panlong Li; Yuanyuan Ma; Jianhang Huang; Duan Bin; Yonggang Wang; Yue Qi; Yongyao Xia

doi:10.1002/anie.201900266

High-Energy Rechargeable Metallic Lithium Battery at -70 °C Enabled by a Cosolvent Electrolyte

Angew Chem Int Ed Engl. 2019 Apr 16;58(17):5623-5627. doi: 10.1002/anie.201900266. Epub 2019 Mar 26.

Authors

Xiaoli Dong¹, Yuxiao Lin², Panlong Li¹, Yuanyuan Ma¹, Jianhang Huang¹, Duan Bin¹, Yonggang Wang¹, Yue Qi², Yongyao Xia^{1

3}

Affiliations

¹ Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Fudan University, Shanghai, 200433, China.
² Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI, 48824, USA.
³ Key Laboratory of the Ministry of Education for Advanced Catalysis, Materials, Department of Chemistry, Zhejiang Normal University, Jinhua, 321004, China.

PMID: 30821403
DOI: 10.1002/anie.201900266

Abstract

Lithium metal is an ideal anode for high-energy rechargeable batteries at low temperature, yet hindered by the electrochemical instability with the electrolyte. Concentrated electrolytes can improve the oxidative/reductive stability, but encounter high viscosity. Herein, a co-solvent formulation was designed to resolve the dilemma. By adding electrochemically "inert" dichloromethane (DCM) as a diluent in concentrated ethyl acetate (EA)-based electrolyte, the co-solvent electrolyte demonstrated a high ionic conductivity (0.6 mS cm^-1 ), low viscosity (0.35 Pa s), and wide range of potential window (0-4.85 V) at -70 °C. Spectral characterizations and simulations show these unique properties are associated with the co-solvation structure, in which high-concentration clusters of salt in the EA solvent were surrounded by mobile DCM diluent. Overall, this novel electrolyte enabled rechargeable metallic Li battery with high energy (178 Wh kg^-1 ) and power (2877 W kg^-1 ) at -70 °C.

Keywords: co-solvent electrolyte; high energy density; lithium-metal batteries; low temperature.

Abstract

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