Utilization of Litchi peel waste to prepare heteroatom-doped carbon materials for high-performance supercapacitors

Addressing the dual challenges of biomass waste disposal and energy material development, this study proposes an innovative pathway to convert litchi peel biomass waste into high-performance carbon materials doped with heteroatoms (N, O), aiming to enhance the electrochemical performance of supercapacitors. Using litchi peel as the carbon source, dicyandiamide as the nitrogen dopant, and a mixture of NaCl/ZnCl2 as the activator, a series of NLPPC-y (y signifies the mass ratio of the mixed salt to LPC) materials were successfully synthesized. Among them, NLPPC-2 exhibited the optimal electrochemical performance, characterized by a high specific capacitance of 346.4 F center dot g- 1, good rate capability, and long-term cyclic stability. Compared to undoped carbon materials (254.5 F center dot g- 1), the heteroatom doping significantly improved the capacitive performance of the material, with NLPPC-2 demonstrating an increased capacitance of 91.9 F center dot g- 1 (36.1 %). This study not only provides a novel method for the preparation of heteroatom-doped carbon materials but also lays a solid foundation for the development of high-performance supercapacitors, showcasing broad application prospects.