TiO2/Carbon Nanosheets Derived from Delaminated Ti3C2‐MXenes as an Ultralong‐Lifespan Anode Material in Lithium‐Ion Batteries

Abstract

Abstract TiO2–carbon nanosheets (TiO2‐C NS) with high electrical conductivity are synthesized by CO2 oxidation of Ti3C2 MXene. Importantly, the synthesized TiO2‐C NS (high TiO2 content of 98.45%) can be used without adding a conductive material to impart electrical conductivity. The electrochemical properties show good capacity reversibility at a current density of 2 A g−1 in coin‐type half‐cells. In particular, a prototype pouch cell of TiO2‐C NS//NCM523 also demonstrates that TiO2‐C NS as an anode material is a good match with commercial cathode materials for lithium‐ion batteries. The good electrochemical performance of TiO2‐C NS is attributed to the following factors: 1) the high surface area has abundant exposed active sites offering more Li+ insertion channels and short pathways of the Li+ and electrons; 2) TiO2‐C NS has structural stability and low volume expansion (<4%) during Li+ insertion and desertion; and 3) the nanostructure of TiO2‐C NS prevents restacking and agglomerating by the surface‐anchored TiO2 nanoparticles. The obtained results suggest that TiO2‐C NS, wherein TiO2 nanoparticles are densely and homogeneously loaded on both sides of the carbon sheets, are a promising anode material for lithium‐ion batteries.

Keywords

• anode materials
• lithium‐ion batteries
• MXene
• TiO 2