Lithiophilic Quinone Lithium Salt Formed by Tetrafluoro-1,4-Benzoquinone Guides Uniform Lithium Deposition to Stabilize the Interface of Anode and PVDF-Based Solid Electrolytes
Yinglu Hu,
Li Liu,
Jingwei Zhao,
Dechao Zhang,
Jiadong Shen,
Fangkun Li,
Yan Yang,
Zhengbo Liu,
Weixin He,
Weiming Zhao,
Jun Liu
Affiliations
Yinglu Hu
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Li Liu
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Jingwei Zhao
Research and Development Center, Guangzhou Tinci Materials Technology Co., Ltd., Guangzhou 510765, China
Dechao Zhang
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Jiadong Shen
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Fangkun Li
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Yan Yang
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Zhengbo Liu
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Weixin He
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Weiming Zhao
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Jun Liu
Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
Poly(vinylidene fluoride) (PVDF)-based composite solid electrolytes (CSEs) are attracting widespread attention due to their superior electrochemical and mechanical properties. However, the PVDF has a strong polar group -CF2-, which easily continuously reacts with lithium metal, resulting in the instability of the solid electrolyte interface (SEI), which intensifies the formation of lithium dendrites. Herein, Tetrafluoro-1,4-benzoquinone (TFBQ) was selected as an additive in trace amounts to the PVDF/Li-based electrolytes. TFBQ uniformly formed lithophilic quinone lithium salt (Li2TFBQ) in the SEI. Li2TFBQ has high lithium-ion affinity and low potential barrier and can be used as the dominant agent to guide uniform lithium deposition. The results showed that PVDF/Li-TFBQ 0.05 with a mass ratio of PVDF to TFBQ of 1:0.05 had the highest ionic conductivity of 2.39 × 10−4 S cm−1, and the electrochemical stability window reached 5.0 V. Moreover, PVDF/Li-TFBQ CSE demonstrated superior lithium dendrite suppression, which was confirmed by long-term lithium stripping/sedimentation tests over 2000 and 650 h at a current of 0.1 and 0.2 mA cm−2, respectively. The assembled solid-state LiNi0.6Co0.2Mn0.2O2||Li cell showed an excellent performance rate and cycle stability at 30 °C. This study greatly promotes the practical research of solid-state electrolytes.
