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 Ti3C2TxMXene 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 Ti3C2Txanode,the mismatched electrode kinetics can be largely alleviated to acquire an enhanced power perfo rmance.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.