Constructing a VS4–V2CTx heterojunction interface to realize an ultra-long lifetime and high rate capability in sodium-ion batteries†
Abstract
The development of high-energy-density Na-ion batteries (SIBs) is hindered by the lack of a high-capacity anode with fast Na-ion reaction kinetics due to the large Na+ radius and slow Na+ diffusion kinetics. Herein, a high specific capacity anode is designed by constructing a double vanadium-based compound (VS4–V2CTx) heterostructure composite. The strong rivet structure bridged according to the S–V–C bonding interaction between VS4 and V2CTx unblocks the three-dimensional channel of electron transport and synergistically promotes ion diffusion and charge transport. In addition, the electrochemical reaction kinetics can be enhanced by adjusting the ratio of the vanadium valence state to facilitate electrocatalytic activity at the VS4–V2CTx heterojunction interface. When used as a SIB anode, the VS4–V2CTx composite exhibits excellent ultra-long cycling performance, with a specific discharge capacity of 322 mA h g−1 after 4000 cycles at a large current density of 10 A g−1. All-vanadium SIBs (Na3V2(PO4)3@C//VS4–V2CTx) are also assembled and showed excellent sodium storage performance with a high reversible capacity of 234 mA h g−1 at 3 A g−1, indicating broad application prospects for vanadium-based sodium storage devices.
- This article is part of the themed collection: 2023 Inorganic Chemistry Frontiers HOT articles