Three-dimensional amorphous carbon rivet vanadium sulfide enhanced lithium storage

Abstract

In this work, vanadium disulfide (VS2) and its carbon composites(VS2/C) were successfully synthesized with three-dimensional nanoflower structure via solvothermal method. A thin carbon layer rivets the surface of VS2 with well-remained large layer spacing, which enables fast diffusion of both electrons and ions as well as improves structural stability during cycles. Benefiting from the rationally modified structure, H-VS2/C composite maintains ultrahigh initial discharge specific capacity of 1713 mAh g−1 with benign Coulombic efficiency (CE) of 70.8 % and remains at 1661 mAh g−1 after 300 cycles. Moreover, after further annealing, T-VS2/C composite exhibits higher initial CE of 82.4 % and delivers excellent cycling stability with reversible capacity of 878 mAh g−1 after 300 cycles, corresponding to capacity retention of 93.4 %. Additionally, superior rate performance is realized even at a harsh 2 C attributed to promoted kinetics, which highlights it as competitive anode for lithium-ion batteries.