A Novel Hybrid Point Defect of Oxygen Vacancy and Phosphorus Doping in TiO2 Anode for High-Performance Sodium Ion Capacitor

A novel hybrid point defect design (HPD) with oxygen vacancies and P-dopant is proposed to solve the insufficient kinetic and low specific capacity problems of TiO2.Through density functional theory calculation and sodium storage characterization, the synergistic effect of HPD is beneficial to improve the conductivity and sodium storage performance of TiO2.The prepared sodium ion capacitors show outstanding power/energy density, ultra-long life and good capacity retention.