T-Nb2O5 nanoparticle enabled pseudocapacitance with fast Li-ion intercalation

Abstract

Orthorhombic Nb₂O₅ (T-Nb₂O₅) nanocrystallites are successfully fabricated through an evaporation induced self-assembly (EISA) method guided by a commercialised triblock copolymer – Pluronic F127. We demonstrate a morphology transition of T-Nb₂O₅ from continuous porous nanofilms to monodisperse nanoparticles by changing the content of Pluronic F127. The electrochemical results show that the optimized monodisperse Nb-2 with a particle size of 20 nm achieves premier Li-ion intercalation kinetics and higher rate capability than mesoporous T-Nb₂O₅ nanofilms. Nb-2 presents an initial intercalation capacity of 528 and 451 C g⁻¹ at current densities of 0.5 and 5 A g⁻¹ and exhibited a stable capacity of 499 C g⁻¹ after 300 charge/discharge cycles and 380 C g⁻¹ after 1000 cycles, respectively. We would expect this copolymer guided monodispersion of T-Nb₂O₅ nanoparticles with high Li⁺ intercalation performance to open up a new window for novel EES technologies.