Acetate Solutions with 3.9 V Electrochemical Stability Window as an Electrolyte for Low-Cost and High-Performance Aqueous Sodium-Ion Batteries

Authors

Dao-Yun Lan, Guangdong University of Technology, Guangzhou 510006, Guangdong, China;
Xiao-Feng Qu, Guangdong University of Technology, Guangzhou 510006, Guangdong, China;
Yu-Ting Tang, Guangdong University of Technology, Guangzhou 510006, Guangdong, China;
Li-Ying Liu, Guangdong University of Technology, Guangzhou 510006, Guangdong, China;
Jun Liu, Guangdong University of Technology, Guangzhou 510006, Guangdong, China;Follow

Corresponding Author

Jun Liu(junliu23@gdut.edu.cn)

Abstract

Low-cost and high-safety aqueous sodium-ion batteries have received widespread attention in the field of large-scale energy storage, but the narrow electrochemical stability window (1.23 V) of water limits the energy density of aqueous sodium-ion batteries. The “water-in-salt” strategy which uses the interaction between cations and water molecules in the solution can inhibit water decomposition and broaden the electrochemical stability window of water. In this work, two types of low-cost salts, namely, ammonium acetate (NH₄CH₃COOH) and sodium acetate (NaCH₃COOH), were used to configure a mixed aqueous electrolyte for aqueous sodium-ion batteries. The solution consisted of 25 mol·L ^-1 NH₄CH₃COOH and 5 mol·L^-1 NaCH₃COOH, used as an aqueous electrolyte, exhibited a wide electrochemical stability window of 3.9 V and high ionic conductivity of 28.2 mS·cm^-1. The composite of layered manganese dioxide and multi-wall carbon nanotubes (MnO₂/CNTs) was used as a positive electrode material, while the carbon-coated NaTi₂(PO₄)₃ with NASICON structure was used as a negative electrode material. Both of these electrode materials had excellent electrochemical performances in the aqueous electrolyte. A full cell achieved an average working voltage of about 1.3 V and a discharge capacity of 74.1 mAh·g^-1 at a current density of 0.1 A·g^-1. This aqueous sodium-ion battery displayed excellent cycling stability with negligible capacity losses (0.062% per cycle) for 500 cycles. The safe and environmentally friendly aqueous acetate electrolyte, with a wide electrochemical stability window, showed the potential to be matched with positive materials having higher potential and negative materials having lower potential for further improving the voltage of aqueous sodium-ion batteries and promoting the development of aqueous batteries for large-scale energy storage technology.

Graphical Abstract

Keywords

sodium ion battery, aqueous electrolyte, ammonium acetate, water-in-salt

DOI Link

https://doi.org/10.13208/j.electrochem.210223

Publication Date

2022-01-28

Online Available Date

2021-03-27

Revised Date

2021-03-10

Received Date

2021-02-22

Recommended Citation

Dao-Yun Lan, Xiao-Feng Qu, Yu-Ting Tang, Li-Ying Liu, Jun Liu. Acetate Solutions with 3.9 V Electrochemical Stability Window as an Electrolyte for Low-Cost and High-Performance Aqueous Sodium-Ion Batteries[J]. Journal of Electrochemistry, 2022 , 28(1): 2102231.
DOI: 10.13208/j.electrochem.210223
Available at: https://jelectrochem.xmu.edu.cn/journal/vol28/iss1/6