Sulfur- and nitrogen-doped rice husk-derived C/SiOx composites as high-performance lithium-ion battery anodes

Abstract To enhance the comprehensive utilization of agricultural waste in new energy materials, sulfur/nitrogen dual-doped porous C/SiOx composites (SN@C/SiOx) are successfully prepared via a facile and economical method. In this approach, rice husks are used as the C and Si source and thiourea as the S and N source. This SN@C/SiOx composite possesses a high specific surface area and SiOx particles are evenly distributed in the S/N-doped C matrix. The S/N-doped C matrix not only improves electrical conductivity and impedes the agglutination of particles, but also buffers the volume variation of SiOx, achieving enhanced electrochemical properties. As a lithium-ion battery (LIBs) anode, the as-synthesized SN@C/SiOx composite delivers an impressive specific capacity (1150 mAh/g) and enhanced initial coulombic efficiency (CE) of 70.4%. Even at a large current density of 1.0 A/g, the reversible capacity remains 632 mAh/g after 1200 cycles. This doping carbonization strategy offers the potential for using rice husks in the development of high-performance lithium ion batteries.