An orderly arrangement of layered carbon Nanosheet/TiO_2 nanosheet stack with superior artificially interfacial lithium pseudocapacity

摘要

Poor rate capability and cyclability are the major barriers to using TiO2 as the next generation anode material for high-performance lithium-ion batteries. In this study, a sandwich-like composite consisting of atomically defined two-dimensional (2D) carbon nanosheet is constructed by the confined synthesis in the galleries of layered TiO2 nanosheet with the superior cycling and rate performances as the anode material for lithium-ion batteries. It is first experimentally revealed that the interfacial charge storage between unilamellar TiO2 nanosheet and carbon nanosheet in the Carbon/TiO2 nanosheet stack and the excellent structure stability during the discharge/charge process contribute to the superior performance of the composites. The resultant composite exhibits a high specific capacity (568 mAh g(-1)) with a specific energy of 407.4 Wh kg(-1) at a specific power of 71.7 W kg(-1), and remains 88.0 Wh kg(-1) at a specific power of 9.0 kW kg(-1). Apart from promising lithium-ion battery anode, this 2D Carbon/TiO2 composite also has immense potential for applications in other areas such as sodium/potassium-ion batteries, supercapacitor, and catalysis.