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Highly Reversible Aqueous Zinc Batteries enabled by Zincophilic–Zincophobic Interfacial Layers and Interrupted Hydrogen‐Bond Electrolytes
Author(s) -
Cao Longsheng,
Li Dan,
Soto Fernando A.,
Ponce Victor,
Zhang Bao,
Ma Lu,
Deng Tao,
Seminario Jorge M.,
Hu Enyuan,
Yang XiaoQing,
Balbuena Perla B.,
Wang Chunsheng
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202107378
Subject(s) - overpotential , faraday efficiency , electrolyte , eutectic system , aqueous solution , inorganic chemistry , electrochemistry , materials science , zinc , chemistry , chemical engineering , metallurgy , electrode , alloy , engineering
Aqueous Zn batteries promise high energy density but suffer from Zn dendritic growth and poor low‐temperature performance. Here, we overcome both challenges by using an eutectic 7.6 m ZnCl 2 aqueous electrolyte with 0.05 m SnCl 2 additive, which in situ forms a zincophilic/zincophobic Sn/Zn 5 (OH) 8 Cl 2 ⋅H 2 O bilayer interphase and enables low temperature operation. Zincophilic Sn decreases Zn plating/stripping overpotential and promotes uniform Zn plating, while zincophobic Zn 5 (OH) 8 Cl 2 ⋅H 2 O top‐layer suppresses Zn dendrite growth. The eutectic electrolyte has a high ionic conductivity of ≈0.8 mS cm −1 even at −70 °C due to the distortion of hydrogen bond network by solvated Zn 2+ and Cl − . The eutectic electrolyte enables Zn∥Ti half‐cell a high Coulombic efficiency (CE) of >99.7 % for 200 cycles and Zn∥Zn cell steady charge/discharge for 500 h with a low overpotential of 8 mV at 3 mA cm −2 . Practically, Zn∥VOPO 4 batteries maintain >95 % capacity with a CE of >99.9 % for 200 cycles at −50 °C, and retain ≈30 % capacity at −70 °C of that at 20 °C.