Templated Freeze-Casting for Porous Organic Battery Electrodes with High-Rate Capabilities

Redox-active polymer (RAP)-based organic electrodes offer versatile energy storage solutions across various battery systems. However, effective dispersion of polymer active materials with conductive additives remains challenging, limiting active site accessibility and material utilization. This study introduces camphene (CAMP), a bio-derived solvent, to fabricate porous organic electrodes through templated freeze casting. Compared to conventional N-methyl-2-pyrrolidone (NMP)-cast electrodes, CAMP-cast electrodes exhibit superior ion diffusion, lower charge transfer resistance, and enhanced reaction kinetics across three different RAPs. This results in excellent rate capabilities and significant capacity retention even at 20 A g⁻¹ current density. At higher mass loadings (>1.0 mg cm⁻²), CAMP-cast electrodes achieve areal capacities of ≈0.15 mAh cm⁻² at 0.5 A g⁻¹ over 1000 cycles and maintain more than 80% capacity retention after 500 cycles at 2 A g⁻¹. These findings demonstrate CAMP's potential as an eco-friendly alternative to NMP for producing high-performance organic electrodes, offering a sustainable approach to advanced energy storage solutions.