Biomass-derived carbon electrode for high capacity and stable lithium-ion batteries

The utilization of agricultural waste to convert it into high-performance energy storage materials can be considered a step toward sustainable progress into the next generation lithium-ion batteries. In this study, the activated carbon was obtained from betel palm shells using a ZnCl 2 -impregnated chemical activation process and subsequent high-temperature treatments under a nitrogen atmosphere. Comprehensive analysis using XRD, Raman and FTIR techniques as well as XPS, BET and TGA studies revealed a highly disordered carbon structure with partial graphitization. The material has a high level of oxygen functionalities (8.71 at%) which displays a hierarchical micro/mesoporous network structure with a surface area and pore volume of 25.91 m 2 g −1 and 0.08 cm 3 g −1 , respectively. Upon evaluating this as an electrode material in lithium half-cell using 1 M LiPF 6 in EC/DMC, the AC-ZnCl 2 -5h-900℃ sample achieved remarkable average specific capacity of 360.64 mAh g −1 and delivered a high-capacity retention rate of 98.6 % over 100 cycles with approximately 100 % coulombic efficiency. The exceptional operation is enabled by a rapid hybrid lithium storage mechanism involving an electric-double layer adsorption, pseudocapacitive surface redox and minimal intercalation, all contributing to fast ionic transport and structural durability. The study demonstrates a sustainable and high-quality strategy for the synthesis of biomass-derived carbons with excellent properties, paving the way to their wide application as electrodes in Li-ion batteries, and other emerging energy-storage technologies. • Activation with ZnCl 2 turns biomass into high-performance Li-ion electrodes. • XPS/FTIR confirm stable oxygen functionalities and stabilized carbon structure. • Optimized ZnCl 2 activation delivers 1.19 S cm −1 electrical conductivity. • 5h-900℃ carbon provides a specific capacity of 360.64 mAh g −1 with retention rate of 98.6 %. • Fast Li + transport and high-rate performance are achieved by hierarchical pores.