Design of Chitin Partial Dissolution System for Construction of High-Efficiency Energy Storage Porous Carbon

Abstract

Chitin is a cost-effective and abundant resource, enriched with nitrogen and oxygen elements, making it an ideal precursor for carbon-based materials. However, traditional methods for preparing activated carbon from chitin often require substantial amounts of activators and complex carbonization processes, leading to suboptimal energy storage efficiency. This study presents a partial dissolution system achieved by modulating the mass ratio of chitin to activators (KOH and urea) and optimizing freeze-thaw cycles. When chitin/KOH/urea is mixed at a 1:1:1.5 mass ratio and subjected to three freeze-thaw cycles, the resulting porous carbon demonstrates a high specific surface area of 1783 m² g⁻¹ with significant N (4.75%) and O (11.16%) doping. The electrode achieves a specific capacitance of 309.1 F g⁻¹ at 0.5 A g⁻¹ in a three-electrode system with 6 m KOH as the electrolyte. After 5000 charge–discharge cycles at 5 A g⁻¹, the capacitance retention rate remains at 91.08%, indicating excellent cycling stability. When assembled into a symmetrical supercapacitor, it exhibits an energy density of 5.69 Wh kg⁻¹ at a power density of 4996.1 W kg⁻¹, demonstrating remarkable energy storage performance. This work introduces a novel method for preparing chitin-derived porous carbon materials.