Reduced Na–S bond adsorption of WSSe enabling fast reaction kinetics in the sodium-ion battery

Abstract

Lamellar WSSe grown in situ on peanut shell-derived carbon (PSDC/WSSe) is elaborately designed as a highly stable SIB anode with a fast kinetic. WS 2 , a two-dimensional layered material, is promising as sodium-ion batteries (SIBs) anode due to its large interlamellar spacing and high sodium storage capacity. However, its low electronic conductivity and high Na + adsorption energy hinder reaction kinetics. Here we demonstrate that substituting Se for part of the S in WS 2 reduces interlayer Na + adsorption and increases electronic conductivity. Based on this finding, lamellar WSSe, grown in situ on peanut shell-derived carbon (PSDC/WSSe), is elaborately designed as a highly stable SIB anode with a fast kinetic. PSDC/WSSe with carbon matrix and Se substitution simultaneously provides fast electron transport channels and lowered Na + transport barriers (0.22 eV). The PSDC/WSSe anode offers a considerable reversible sodium storage capacity (288.0 mAh g −1 after 1000 cycles at 1.0 A g −1 ) and a fast kinetic reaction. A SIB full-cell using a PSDC/WSSe anode and Na 3 V 2 (PO 4 ) 3 cathode achieves a 215.4 Wh kg −1 high energy density, and successfully powers LEDs. This work offers new strategies to lower sodium ion transportation barrier in two-dimensional layered materials.