TiO<sub>2</sub>/Carbon Nanosheets Derived from Delaminated Ti<sub>3</sub>C<sub>2</sub>‐MXenes as an Ultralong‐Lifespan Anode Material in Lithium‐Ion Batteries
Dong Kyu Lee, Chi Won Ahn, Jae Wook Lee
Abstract
Abstract TiO 2 –carbon nanosheets (TiO 2 ‐C NS) with high electrical conductivity are synthesized by CO 2 oxidation of Ti 3 C 2 MXene. Importantly, the synthesized TiO 2 ‐C NS (high TiO 2 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 TiO 2 ‐C NS//NCM523 also demonstrates that TiO 2 ‐C NS as an anode material is a good match with commercial cathode materials for lithium‐ion batteries. The good electrochemical performance of TiO 2 ‐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) TiO 2 ‐C NS has structural stability and low volume expansion ( < 4%) during Li + insertion and desertion; and 3) the nanostructure of TiO 2 ‐C NS prevents restacking and agglomerating by the surface‐anchored TiO 2 nanoparticles. The obtained results suggest that TiO 2 ‐C NS, wherein TiO 2 nanoparticles are densely and homogeneously loaded on both sides of the carbon sheets, are a promising anode material for lithium‐ion batteries.