Enhanced Li-ion migration behavior in Li3V2O5 rock-salt anode via stepwise lattice tailoring

Electrode exploration with the appropriate equilibrium voltage and facile cation diffusion kinetics is the key enabler towards realizing the extreme power output of the battery formats. With the aid of the stepwise lattice tailoring, herein, we present an alternative fast-charging anode of the rock-salt lithium vanadium oxide. Specifically, the pre-insertion of polyaniline (PANI) molecules unlocks the basal plane of the layered V2O5 precursor, while subsequent Na+ doping at the octahedral sites could stabilize the lattice breathing and mitigate Li-ion diffusion barrier along the tetrahedron-octahedron-tetrahedron pathway, as confirmed by the operando X-ray diffraction and kinetics simulation. The Na0.6Li2.4V2O5@PANI//LiFePO4 full cell prototype (3 mAh cm−2) exhibits 82% capacity retention at 20 C for 2000 cycles, as well as the cycling endurance within a wider temperature range of 0-60°C. This stepwise lattice engineering strategy opens a fresh impetus of the electrode innovations for the high-power energy storage devices.