Carbon doping switching on the fast reaction kinetics of advanced LiVO3 for lithium ion battery

摘要

LiVO3 has been recognized as a promising anode material for lithium storage because of its superior ion transfer capability and high theoretical capacity (1265 mAh g-1). However, its low electrical conductivity and hysteresis of the reaction kinetics limit the improvement of its electrochemical performance. In this work, carbon-doped LiVO3 nanofibers (C-doped LiVO3 NFs) are firstly designed and prepared via a simple and scalable electrospinning technique. The as-obtained C-doped LiVO3 NFs deliver high discharge capacity (913.7 mAh g-1 after 500 cycles at 0.2 A g-1) with obvious rise in capacity upon cycling, owing to its self -adaptive reaction kinetics. Moreover, the C-doped LiVO3 NFs electrode retains a high average discharge capacity of 676.2 mAh g-1 at 6.0 A g-1 and resumes the reversible capacity of 1137.5 mAh g-1 when the current returns to 0.2 A g-1 after 7 periodic rate performance tests. Surprisingly, the C-doped LiVO3 NFs anode exhibits an unprecedented long cycling performance with the capacity remaining at 560.3 mAh g-1 after 4200 cycles at the discharge current density of 4.0 A g-1. The above outstanding comprehensive electrochemical performance is attributed to rapid ion and electron transport triggered by carbon doping and the adaptive reaction kinetics of the C-doped LiVO3 NFs electrode, which is manifested in the gradually decreasing charge transfer impedance and the gradually increasing pseudocapacitance contribution upon cycling.

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