Boosting the Energy Density of Li||CF x Primary Batteries Using a 1,3-Dimethyl-2-imidazolidinone-Based Electrolyte

Ang Fu; Yukang Xiao; Junhua Jian; Lin Huang; Chao Tang; Xunxin Chen; Yue Zou; Jiuzhou Wang; Yong Yang; Jianming Zheng

doi:10.1021/acsami.1c19016

Boosting the Energy Density of Li||CF _x Primary Batteries Using a 1,3-Dimethyl-2-imidazolidinone-Based Electrolyte

ACS Appl Mater Interfaces. 2021 Dec 8;13(48):57470-57480. doi: 10.1021/acsami.1c19016. Epub 2021 Nov 24.

Authors

Ang Fu¹, Yukang Xiao¹, Junhua Jian², Lin Huang¹, Chao Tang², Xunxin Chen¹, Yue Zou¹, Jiuzhou Wang³, Yong Yang¹, Jianming Zheng¹

Affiliations

¹ State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
² Ningde Amperex Technology Limited, Ningde 352100, China.
³ Tianjin Institute of Power Sources, Tianjin 300384, China.

PMID: 34816716
DOI: 10.1021/acsami.1c19016

Abstract

Elevating the discharge voltage plateau is regarded as the most effective strategy to improve the energy density of Li||CF_x batteries in consideration of the finite capacity of CF_x (x ∼ 1) cathodes. Here, an electrolyte, with LiBF₄ in 1,3-dimethyl-2-imidazolidinone (DMI)/1,2-dimethoxyethane (DME), is developed for the first time to substantially promote the discharge voltage of CF_x without compromising the available discharge capacity. DME possesses the property of low viscosity, while DMI functions to increase the voltage plateau during discharge owing to its moderate nucleophilicity and donor number, which decreases the energy barrier for breaking C-F bonds. The optimized electrolyte exhibits a significantly high average discharge voltage of 2.69 V at a current density of 10 mA g^-1, which is 11.6% higher than the control electrolyte (2.41 V). In addition, a high energy density of 2099 Wh kg^-1 is achieved in the optimized electrolyte (vs 1905 Wh kg^-1 in the control electrolyte), showing great potential for practical applications.

Keywords: 1,3-dimethyl-2-imidazolidinone (DMI); CFx primary batteries; electrolyte; high discharge voltage plateau; interfacial reaction kinetics.