Mott–Schottky Effect in Core–Shell W@W<i><sub>x</sub></i>C Heterostructure: Boosting Both Electronic/Ionic Kinetics for Lithium Storage
Yao Yang, Bing Sun, Yinhong Gao, Hui Zhu, Yongting Chen, Xuanke Li, Qin Zhang
Abstract
Abstract The dynamics rate of traditional metal carbides (TMCs) is relatively slow, severely limiting its fast‐charging capacity for lithium‐ion batteries (LIBs). Herein, the core–shell W@W x C heterostructure is developed to form Mott–Schottky heterostructure, thereby simultaneously accelerating the electronic and ionic transport kinetics during the charging/discharging process. The W nanoparticles are partially reduced into W x C to form a particular core–shell structure with abundant heterogeneous interfaces. Benefiting from the Mott–Schottky effect, the electrons at the metal/semiconductor heterointerface can migrate spontaneously to realize an equal work function on both sides. In addition, the independent nanoparticle as well as the unique core–shell structure facilitate the ionic diffusion kinetics. As expected, the W@W x C electrode exhibits excellent electrochemical stability for LIBs, whose capacity can be maintained at 173.8 mA h g −1 after 1600 cycles at a high current density of 5 A g −1 . When assembled into a full cell, it can achieve an energy density of 360.2 Wh kg −1 . This work presents a new avenue to promote the electronic and ionic kinetics for LIBs anodes by constructing the unique Mott–Schottky heterostructure.