Energy Storage Science and Technology ›› 2024, Vol. 13 ›› Issue (7): 2124-2130.doi: 10.19799/j.cnki.2095-4239.2024.0307

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

1,3-Difluorobenzene diluent-stabilizing electrode interface for high-performance low-temperature lithium metal batteries

Shijie LIAO1(), Ying WEI1, Yunhui HUANG1, Renzong HU2, Henghui XU1()   

  1. 1.Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
    2.South China University of Technology, Guangzhou 510641, Guangdong, China
  • Received:2024-04-07 Revised:2024-04-16 Online:2024-07-28 Published:2024-07-23
  • Contact: Henghui XU E-mail:m202271054@hust.edu.cn;xuhh@hust.edu.cn

Abstract:

Lithium-ion batteries are widely used across various industries owing to their superior characteristics such as high energy density, high output voltage, and prolonged cycle life. However, their electrochemical efficiency drastically declines in low-temperature conditions, constraining their practical applications. To overcome this limitation, a novel low-temperature electrolyte, distinguished by exceptional cycling performance at ambient and low temperatures, was developed using fluoro-substituted benzene with varied fluorine substitution positions as diluents. Notably, the use of 1, 3-difluorobenzene as a diluent led to the development of an electrolyte, designated as 13DFB, exhibiting a conductivity of 1.252 mS/cm at -20 ℃ and a broad electrochemical window of 5.2 V. The inclusion of 1, 3-difluorobenzene in the electrolyte considerably reduces the formation of Li2CO3 in solid-electrolyte interphase and provides a protective layer to LiNi0.6Co0.2Mn0.2O2 (NCM 622) cathode particles. Moreover, when this modified electrolyte is used in a pouch cell configuration with a Li/NCM 622 combination at -20 ℃ and a cutoff voltage of 4.4 V, it achieves stable cycling for 200 cycles with a capacity retention of 92.8%. This study introduces an effective and straightforward strategy to enhance the low-temperature performance of electrolytes, demonstrating substantial potential for practical deployment.

Key words: lithium-ion battery, low temperature electrolyte, 1,3-difluorobenzene, diluent

CLC Number: