Flower-like carbon-confined disordered rock-salt LiVO2 anode with a sandwich structure for fast charging and stable lithium storage

Abstract

Disordered rock-salt (DRS) LiVO₂ has attracted enormous attention for use as a fast-charging anode due to its high Li⁺ diffusion efficiency. However, sluggish interfacial kinetics hinder the electrochemical performance despite LiVO₂ having rapid bulk-phase transport dynamics. Herein, we design flower-like N-doped carbon-confined LiVO₂ with a sandwich structure (LiVO₂/NC NFs) through an in situ grafting approach using polyacrylonitrile (PAN) as a template. Part of the cyano groups of PAN was hydrolyzed into carboxylate ions, promoting strong adhesion between the PAN and LiVO₂ precursors due to electrostatic interactions, thus ensuring the DRS structure and a continuous charge-transfer pathway for the LiVO₂/NC NF electrode. The obtained LiVO₂/NC heterointerface provides abundant active sites and enhances the interfacial transport kinetics of the ions. As a result, the LiVO₂/NC NFs electrode exhibits excellent electrochemical performances (including an average discharge capacity of 415 mA h g⁻¹ at 8.0 A g⁻¹ after 4 periodic rate tests over 250 cycles, and a discharge capacity of 223 mA h g⁻¹ at a high discharge current of 10.0 A g⁻¹ after 5000 cycles), outperforming other LiVO₂-based anodes. It is hoped that the design strategy of LiVO₂/NC NFs will provide impetus for further development of fast-charging electrodes.