Solvent-assisted ligand exchange induces the epitaxial growth of VSe2 on the surface of 3D nitrogen-doped carbon network for ultra-long-life lithium/sodium-ion batteries

Abstract

Metal selenides (MSes) exhibit potential as lithium-ion batteries (LIBs)/sodium-ion batteries (SIBs) anodes owing to high-capacity and conductive properties, yet struggle with volume expansion and polyselenide shuttling issues. Herein, synthesized V-MOF based on the solvent-assisted ligand exchange method, the VSe 2 composite material anchored by the nitrogen-doped carbon matrix was successfully prepared. The findings demonstrate that the NC layer effectively inhibits VSe 2 structural expansion and polyselenide dissolution. The optimized VSe 2 /NC anode displays exceptional cycling durability: 192 mAh g -1 (LIBs, 10A g -1 , 4500 cycles) and 314.4 mAh g -1 (SIBs, 2A g -1 , 500 cycles). Its full-cell (VSe 2 /NC||LiCoO 2 ) delivers 127.5 Wh kg -1 energy density and 85 W kg -1 power density, maintaining 83.43% capacity after 300 cycles (0.2C) while illuminating 202 LEDs for 5min. Experimental and density functional theory (DFT) calculation all reveal that excellent battery performance comes from NC incorporation induces hierarchical pores and structural defects, boosting alkali-ion migration rates and storage site density. This work establishes a new design strategy for high-rate battery anode materials.