Self-supported VO2 arrays decorated with N-doped carbon as an advanced cathode for lithium-ion storage

Abstract

The development of advanced cathodes for lithium-ion batteries (LIBs) with high capacity and large energy density is of significant importance. Herein, we report a facile solvothermal-polymerization approach for the fabrication of self-supported VO₂ arrays decorated with N-doped carbon (N–C@VO₂). A thin N–C shell obtained from polymerized dopamine was uniformly coated on the solvothermal-synthesized VO₂ skeleton, and self-supported composite arrays were formed. The lithium storage performance of the designed N–C@VO₂ arrays was thoroughly studied. Due to the enhanced conductivity and more stable structure, the N–C@VO₂ arrays exhibited much better reactivity and high-rate capability with a higher capacity (295 mA h g⁻¹vs. 254 mA h g⁻¹ at 1C) and an improved high-rate cycling life (95.3% vs. 91.5% after 500 cycles at 1C) as compared to the pure VO₂ arrays. The synergistic effect between the array architecture and the N–C shell is responsible for the performance enhancement due to the accelerated reaction kinetics. Our research shows a new way to fabricate advanced high-capacity cathodes for application in electrochemical energy storage.