Designing electron/ion dual-phase conductor Ni@TiO2 for high-performance lithium-ion storage: Combining insertion and space charge mechanism

In this study, we construct an yolk-shell Ni@TiO2 nanosphere to investigate its performance in lithium-ion batteries. The composite possesses a synergistic storage mode consisting of a Li+-accepting and an electron-accepting phase. Used as an anode material, it delivers ultra-high specific capacity with excellent rate performance and cycling stability. In situ magnetic characterization and thermodynamic simulation reveal the existence of space charge storage mechanism. We propose an overall view on the Li storage mechanism of the Ni@TiO2 and demonstrate the importance of space charge storage for performance improvement in Li-ion batteries.