Energy Storage Science and Technology ›› 2024, Vol. 13 ›› Issue (7): 2308-2316.doi: 10.19799/j.cnki.2095-4239.2024.0426

• Special Issue on Low Temperature Batteries • Previous Articles     Next Articles

Advances in low-temperature electrolytes for potassium-ion batteries

Fei ZHAO1,2(), Yinghua CHEN1,2, Zheng MA1, Qian LI1(), Jun MING1,2()   

  1. 1.State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin, China
    2.University of Science and Technology of China, Hefei 230026, Anhui, China
  • Received:2024-05-13 Revised:2024-06-07 Online:2024-07-28 Published:2024-07-23
  • Contact: Qian LI, Jun MING E-mail:zhaojunhua@ciac.ac.cn;qianli@ciac.ac.cn;jun.ming@ciac.ac.cn

Abstract:

Potassium-ion batteries (PIBs) have emerged as a potential energy storage device due to their high energy density and low cost. In particular, the smaller Stokes radius of K+ enables ultra-low temperature potassium-ion batteries. However, conventional electrolytes can cause PIBs to grow dendrites at low temperatures, leading to battery failure and safety hazards. Therefore, improving the low-temperature properties of the electrolyte is crucial to improving the low-temperature performance of PIBs. This study reviews the progress made in recent years related to low-temperature electrolytes for PIBs, which can be roughly divided into three categories, namely non-aqueous electrolytes, aqueous electrolytes, and solid electrolytes. Non-aqueous electrolytes mostly contain weakly solvating ether solvents and additives, which enhance the interfacial desolvation process and form a good solid electrolyte interface film on the electrode surface to improve the low-temperature performance of PIBs. The aqueous electrolyte helps PIBs to achieve good low-temperature performance by introducing specific additive molecules to lower the electrolyte freezing point and destroy the network of hydrogen bonds between the H2O molecules. The quasi-solid-state electrolyte, which retains a small amount of liquid electrolyte in the channels of the polymer skeleton, improves the electrolyte bulk ion transport and reduces the contact resistance between the electrolyte and the electrode interface, which ultimately improves the low-temperature performance of PIBs.

Key words: potassium ion battery, low-temperature performance, non-aqueous electrolyte, aqueous electrolyte, solid-state electrolyte

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