Electrochemical Lithium Storage Performance of Molten Salt Derived V2SnC MAX Phase

Youbing Li; Guoliang Ma; Hui Shao; Peng Xiao; Jun Lu; Jin Xu; Jinrong Hou; Ke Chen; Xiao Zhang; Mian Li; Per O Å Persson; Lars Hultman; Per Eklund; Shiyu Du; Zhifang Chai; Zhengren Huang; Na Jin; Jiwei Ma; Ying Liu; Zifeng Lin; Qing Huang

doi:10.1007/s40820-021-00684-6

Electrochemical Lithium Storage Performance of Molten Salt Derived V₂SnC MAX Phase

Nanomicro Lett. 2021 Jul 22;13(1):158. doi: 10.1007/s40820-021-00684-6.

Authors

Youbing Li^#^{1

2}, Guoliang Ma^#³, Hui Shao⁴, Peng Xiao³, Jun Lu⁵, Jin Xu⁶, Jinrong Hou⁷, Ke Chen^{1

2}, Xiao Zhang^{1

2}, Mian Li^{1

2}, Per O Å Persson⁵, Lars Hultman⁵, Per Eklund⁵, Shiyu Du^{1

2}, Zhifang Chai^{1

2}, Zhengren Huang^{1

2}, Na Jin³, Jiwei Ma⁷, Ying Liu³, Zifeng Lin⁸, Qing Huang^{9

10}

Affiliations

¹ Engineering Laboratory of Advanced Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo, 315201, Zhejiang, People's Republic of China.
² Qianwan Institute of CNiTECH, Ningbo, 315336, People's Republic of China.
³ College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, People's Republic of China.
⁴ CIRIMAT UMR CNRS 5085, Université Toulouse III- Paul Sabatier, 118 route de Narbonne, 31062, Toulouse Cedex 9, France.
⁵ Department of Physics, Chemistry and Biology (IFM), Linköping University, 58183, Linköping, Sweden.
⁶ School of Machine Engineering, Dongguan University of Technology, Dongguan, 523808, People's Republic of China.
⁷ Institute of New Energy for Vehicles, School of Materials Science and Engineering, Tongji University, Shanghai, 201804, People's Republic of China.
⁸ College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, People's Republic of China. linzifeng@scu.edu.cn.
⁹ Engineering Laboratory of Advanced Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo, 315201, Zhejiang, People's Republic of China. huangqing@nimte.ac.cn.
¹⁰ Qianwan Institute of CNiTECH, Ningbo, 315336, People's Republic of China. huangqing@nimte.ac.cn.

^# Contributed equally.

Abstract

MAX phases are gaining attention as precursors of two-dimensional MXenes that are intensively pursued in applications for electrochemical energy storage. Here, we report the preparation of V₂SnC MAX phase by the molten salt method. V₂SnC is investigated as a lithium storage anode, showing a high gravimetric capacity of 490 mAh g^-1 and volumetric capacity of 570 mAh cm^-3 as well as superior rate performance of 95 mAh g^-1 (110 mAh cm^-3) at 50 C, surpassing the ever-reported performance of MAX phase anodes. Supported by operando X-ray diffraction and density functional theory, a charge storage mechanism with dual redox reaction is proposed with a Sn-Li (de)alloying reaction that occurs at the edge sites of V₂SnC particles where Sn atoms are exposed to the electrolyte followed by a redox reaction that occurs at V₂C layers with Li. This study offers promise of using MAX phases with M-site and A-site elements that are redox active as high-rate lithium storage materials.

Keywords: Energy storage; High-rate; Lithium storage; MAX phase; Molten salt.