Enabling an Inorganic-Rich Interface via Cationic Surfactant for High-Performance Lithium Metal Batteries

Zejun Sun; Jinlin Yang; Hongfei Xu; Chonglai Jiang; Yuxiang Niu; Xu Lian; Yuan Liu; Ruiqi Su; Dayu Liu; Yu Long; Meng Wang; Jingyu Mao; Haotian Yang; Baihua Cui; Yukun Xiao; Ganwen Chen; Qi Zhang; Zhenxiang Xing; Jisheng Pan; Gang Wu; Wei Chen

doi:10.1007/s40820-024-01364-x

Enabling an Inorganic-Rich Interface via Cationic Surfactant for High-Performance Lithium Metal Batteries

Nanomicro Lett. 2024 Mar 4;16(1):141. doi: 10.1007/s40820-024-01364-x.

Authors

Zejun Sun^#¹, Jinlin Yang^#², Hongfei Xu¹, Chonglai Jiang^{1

3}, Yuxiang Niu¹, Xu Lian¹, Yuan Liu¹, Ruiqi Su¹, Dayu Liu¹, Yu Long^{1

3}, Meng Wang^{1

3}, Jingyu Mao⁴, Haotian Yang^{1

3}, Baihua Cui^{1

3}, Yukun Xiao^{1

3}, Ganwen Chen^{1

3}, Qi Zhang¹, Zhenxiang Xing⁵, Jisheng Pan⁵, Gang Wu⁶, Wei Chen^{7

8

9}

Affiliations

¹ Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore.
² Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore. [email protected].
³ Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, People's Republic of China.
⁴ Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore.
⁵ Agency for Science, Technology, and Research (A*STAR), Institute of Materials Research and Engineering, Innovis, 2 Fusionopolis Way, #08-03, Singapore, 138634, Singapore.
⁶ Agency for Science, Technology and Research (A*STAR), Institute of High-Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore, 138632, Singapore. [email protected].
⁷ Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore. [email protected].
⁸ Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore. [email protected].
⁹ Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, People's Republic of China. [email protected].

^# Contributed equally.

Abstract

An anion-rich electric double layer (EDL) region is favorable for fabricating an inorganic-rich solid-electrolyte interphase (SEI) towards stable lithium metal anode in ester electrolyte. Herein, cetyltrimethylammonium bromide (CTAB), a cationic surfactant, is adopted to draw more anions into EDL by ionic interactions that shield the repelling force on anions during lithium plating. In situ electrochemical surface-enhanced Raman spectroscopy results combined with molecular dynamics simulations validate the enrichment of NO₃^-/FSI^- anions in the EDL region due to the positively charged CTA⁺. In-depth analysis of SEI structure by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry results confirmed the formation of the inorganic-rich SEI, which helps improve the kinetics of Li⁺ transfer, lower the charge transfer activation energy, and homogenize Li deposition. As a result, the Li||Li symmetric cell in the designed electrolyte displays a prolongated cycling time from 500 to 1300 h compared to that in the blank electrolyte at 0.5 mA cm^-2 with a capacity of 1 mAh cm^-2. Moreover, Li||LiFePO₄ and Li||LiCoO₂ with a high cathode mass loading of > 10 mg cm^-2 can be stably cycled over 180 cycles.

Keywords: Cationic surfactant; Electric double layer; Lithium metal batteries; Lithium nitrate additive; Solid–electrolyte interphase.