Accordion-like titanium carbide (MXene) with high crystallinity as fast intercalative anode for high-rate lithium-ion capacitors

Two-dimensional transition-metal carbide materials, or MXenes, have attracted great attention in energy-related fields due to their excellent electrical conductivity, and large interlayer spacing. In this work, a simple method involving combustion synthesis and acid treatment to prepare accordion-like Ti3C2Tx MXene with open structure and high crystallinity, which is employed as anode materials in lithium-ion capacitors. Due to the improved ion diffusion and electron transportation of Ti3C2Tx anode, the mismatched electrode kinetics can be largely alleviated to acquire an enhanced power performance. The assembled Ti3C2Tx-based lithium-ion capacitors provides a maximum energy density of 106 Wh/kg and still exhibits a superior energy density of 79 Wh/kg even at a higher power density of 5.2 kW/kg, which provides a new platform for MXene materials with porous and crystalline features toward both high energy and power densities. (C) 2020 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.