Intercalation pseudocapacitance in 2D N-doped V2O3 nanosheets for stable and ultrafast lithium-ion storage

2D N-doped V2O3 (N-V2O3) nanosheets were fabricated as anode materials for Li-ion batteries by a facile sol-gel method and a subsequent deoxidation-nitridation strategy. Benefiting from the 3D V-V tunnel structure, sufficient active sites and nitrogen modifications, N-V2O3 nanosheets exhibit improved Li+ diffusion kinetics, robust structure and enhanced conductivity. As a result, N-V2O3 nanosheets show a high specific capacity, long cycling life and high rate capability (136 mA h g(-1) even after 1000 cycles at 2 A g(-1)) as anode materials for Li-ion batteries. It is instructive to note that the efficient Li+ storage of N-V2O3 is dominated by intercalation pseudocapacitance. In the mechanism of intercalation pseudocapacitance, lithium ions are intercalated into the 3D V-V tunnels and adsorbed to the V-O active sites without crystalline phase transition. This mechanism combines long cycling life with short charging/discharging times, which is suitable for stable and ultrafast Li-ion storage.