Kinetics modulation of titanium niobium oxide via hierarchical MXene coating for high-rate and high-energy density lithium-ion half/full batteries

Abstract Titanium niobium oxide has great potential in fast charging and discharging due to the high capacity at large rate. But its poor capacity retention rate seriously restricts the further development. MXene, a two-dimensional transition metal carbide with high conductivity, was adopted to complex with TiNb2O7 (TNO) to improve the electrochemical performance. TNO coated with MXene exhibits better conductivity and limited volume expansion, which benefits the capacity and stability of TNO in the cycle process. The capacity of TNO@MXene remains 153 mAh g−1 after 2000 cycles at 10 C, and the capacity retention rate is 81.4%. The capacity of TNO@MXene can reach 145 mAh g−1 after 5000 cycles at 20 C, and the capacity retention rate is 77.1%. The full battery was assembled using commercial NCM811 as the cathode material, and its energy density was 241.7 Wh kg−1, further verifying its potential application.