Ratio-optimized NiCo scaffolding integration with biomass-derived carbon for efficient lithium-ion battery performance

Abstract

Biomass-derived carbon-supported transition-metal hydroxides are promising anode materials for high-performance lithium-ion batteries (LIBs). Optimizing the morphology and transition-metal molar ratio of layered double hydroxide (LDH) enhances sustainability, redox activity, and charge transport during energy storage. In this study, a highly porous, and large surface area (∼1700 m 2 /g) activated carbon derived from mandarin peel (AC bio ) was integrated with different Ni/Co molar ratio layered double hydroxide nanosheets through a facile solvothermal strategy to construct NiCo-LDH/AC bio hybrid anodes. Structural topological analyses confirmed the successful formation of crystalline NiCo-LDH with distinct nanosheets morphology mixed with the amorphous porous carbon scaffold. Strategically, the AC bio provide abundant anchoring sites, conductive pathways, and interconnected channels for electrolyte penetration. The optimized NiCo-LDH/AC bio composite exhibits a well-coupled LDH/carbon architecture, homogeneous distributions of Ni, Co, C, and O, and a clear lattice spacing of 0.234 nm assigned to the (015) plane of NiCo-LDH. Owing to synergistic interaction between the Ni-rich LDH nanosheets and conductive AC bio , the NiCo-LDH/AC bio (3:1) electrode delivered a high first-cycle discharge capacity of 1658.80 mAh/g and a charge capacity of 810.53 mAh/g at 200 mA/g. After 150 cycles at this current density, it maintained the highest reversible capacity of 410.05 mAh/g. It also exhibited excellent rate capability, with ∼99% coulombic efficiency at high current densities, maintaining a capacity above 250 mAh/g after 1200 cycles at 1000 mA/g. This improved performance stems from numerous Ni/Co redox-active sites, enhanced electronic conductivity, rapid Li + diffusion, and the structural buffering provided by the porous carbon matrix. This study presents a sustainable method for converting biomass waste into advanced, carbon-supported LDH anodes suitable for durable LIB devices.