Synthesis and performance investigation of carbide slag mixing carbonized corn fiber based phase-change composites for potential solar energy storage

Supporting China's carbon neutrality goals requires urgent development of solid waste valorization and high-performance energy storage materials. This work prepares composite phase change materials utilizing carbide slag and carbonized corn fiber as skeleton materials. The combination of industrial and agricultural waste provides a low-cost and environmentally friendly framework. Paraffin serves as the phase change medium. Vacuum impregnation achieved effective encapsulation at an optimal 5:5 mass ratio of these two solid wastes. The composite demonstrated stable thermal cycling. A comprehensive analysis of thermal properties, microstructure, and chemical compatibility was performed. The optimized composite exhibits latent heats of 34.90 J/g (melting) and 36.35 J/g (solidification), along with a thermal conductivity of 0.484 W/(m·K). The dual-skeleton structure facilitates efficient heat transfer while maintaining structural integrity. This work provides a sustainable route to convert waste resources into high-performance energy storage materials, offering promising potential for applications in thermal management and building energy conservation. • Carbide slag and corn fiber first used to prepare low-carbon phase-change composites. • Thermal storage capacity reach 36.35 J/g with thermal conductivity of 0.484 W/(m·K). • Sample at optimal ratio shows great performance After 600 heating-cooling cycles. • Enhanced thermal stability and compatibility ensure reliable cyclic performance. • Phase-change composites prepared in this work are extremely low cost low carbon.