In Situ Synthesis of MoC1- x Nanodot@Carbon Hybrids for Capacitive Lithium-Ion Storage

Jie Lin; Jijian Xu; Wei Zhao; Wujie Dong; Ruizhe Li; Zhichao Zhang; Fuqiang Huang

doi:10.1021/acsami.9b03230

In Situ Synthesis of MoC_{1- x} Nanodot@Carbon Hybrids for Capacitive Lithium-Ion Storage

ACS Appl Mater Interfaces. 2019 Jun 5;11(22):19977-19985. doi: 10.1021/acsami.9b03230. Epub 2019 May 24.

Authors

Jie Lin^{1

2}, Jijian Xu¹, Wei Zhao¹, Wujie Dong^{1

3}, Ruizhe Li^{1

2}, Zhichao Zhang¹, Fuqiang Huang^{1

3

4}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure , Shanghai Institute of Ceramics, Chinese Academy of Sciences , Shanghai 200050 , P. R. China.
² University of Chinese Academy of Sciences , Beijing 100049 , P. R. China.
³ State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China.
⁴ Suzhou Research Institute , Shanghai Institute of Ceramics, Chinese Academy of Sciences , Taicang 215400 , Jiangsu , P. R. China.

PMID: 31070350
DOI: 10.1021/acsami.9b03230

Abstract

In this study, in situ synthesis of carbon-coated MoC_{1- x} nanodots anchored on nitrogen-doped carbon (MoC_{1- x}@C) for lithium storage is reported. The obtained MoC_{1- x}@C hybrids exhibit intriguing structural characteristics including ultrafine particle size (ca. 1.2 nm) of MoC_{1- x} nanodots, porous structure of nitrogen-doped carbon matrix, and good robustness. When evaluated as anodes for lithium-ion batteries, the optimized MoC_{1- x}@C sample demonstrates a superior specific capacity (1099.2 mA h g^-1 at 0.1 A g^-1) and good rate capability (369.1 mA h g^-1 at 5 A g^-1). The MoC_{1- x}@C anode also presents remarkable cycling stability with a much higher specific capacity (657.9 mA h g^-1) than that of commercial bulk MoC (91.4 mA h g^-1) after 500 cycles at 1 A g^-1. Kinetics analysis of the anodes reveals the charge storage mechanism, which demonstrates the existence of capacitive redox reactions occurring at the shallow surface of the MoC_{1- x} nanodots and closely relating to the particle size. The outstanding electrochemical performance results from the synergistic effect of the elastic carbonaceous encapsulation to accommodate the huge volume expansion and the ultrafine MoC_{1- x} nanodots to provide more reactive sites for capacitive lithium storage.

Keywords: anode materials; capacitive; lithium-ion battery; molybdenum carbide; nanodots.