Establish TiNb₂O₇@C as Fast-Charging Anode for Lithium-Ion Batteries

Intercalation-type metal oxides are promising active anode materials for the fabrication of safer rechargeable lithium-ion batteries, as they are capable of minimizing or even eliminating Li plating at low voltages. Due to the excellent cycle performance, high specific capacity and appropriate working potential, TiNb₂O₇ (TNO) is considered to be the candidate of anode materials. Despite a lot of beneficial characteristics, the slow electrochemical kinetics of the TNO-based anodes limits their wide use. In this paper, TiNb₂O₇@C was prepared by using the self-polymerization coating characteristics of dopamine to enhance the rate-performance and cycling stability. The TNO@C-2 particles present ideal rate performance with the discharge capacity of 295.6 mA h g^-1 at 0.1 C. Moreover, the TNO@C-2 anode materials exhibit initial discharge capacity of 177.4 mA h g^-1, providing 91% of capacity retention after 400 cycles at 10 C. The outstanding electrochemical performance can be contributed to the carbon layer, which builds fast lithium ion paths, enhancing the electrical conductivity of TNO. All these results confirm that TNO@C is a valid methodology to enhance rate-performance and cycling stability and is a new way to provide reliable and quickly rechargeable energy storage resources.