Abundant Lithiophilic VO2/V8C7 Heterostructures Boost Charge Transfer toward High-Rate Lithium Storage

Abstract

The construction of a heterogeneous structure on an electrode can enhance its absorption energy, thereby improving ionic diffusion and reaction kinetics. Herein, hyperdispersed VO2/V8C7 nano-heterostructures anchored on carbon nanofibers (VO2/V8C7@CNF), which are further utilized as a lithium anode are successfully developed. The self-supported VO2/V8C7@CNF electrode features a synergistic effect, resulting from its well-dispersed nano-heterostructure, induced hetero-interfacial electric field, and conspicuous lithiophilicity. This anode thus facilitates rapid Li+ ions diffusion and charge transfer, resulting in high-rate performance and uniform Li deposition. It exhibits a reversible specific capacity of as high as 674.8 mA h g−1 at a current density of 0.1 A g−1 and maintains a high-rate capability of 205.3 mA h g−1 at a current density of as high as 5.0 A g−1 even after undergoing 1000 charge/discharge cycles. The Li-ion nucleation overpotential on this anode is significantly reduced to 27 mV. The hyperdispersed nano-heterostructure strategy offers a universal blueprint for the fabrication of high-performance anodes not only for lithium and other batteries.