Porous carbon materials prepared via thermally-induced phase separation for supercapacitors

Abstract

Thermoplastic polyurethane (TPU) is an extensively used polymer that has caused environmental pollution. TPU-derived carbon has potential economic value for waste utilization as electrodes for supercapacitors, but transforming TPU into porous carbon materials with high specific surface area, suitable pore size distribution and good conductivity remains a difficult problem. Herein, three-dimensional porous TPU composite monomers with a macroporous structure were synthesized by a green and environmentally friendly thermal phase separation method, where the TPU skeleton was strategically broken and reconnected. An optimal TPU-derived porous carbon material pre‑carbonized at 350 °C (TPU-350) was successfully obtained. Benefiting from its effective chemical activation and ion accessibility due to phase separation-induced interconnected skeleton, the TPU-350 exhibits a specific gravimetric capacitance of 376.9 F g⁻¹ a current density of 1 A g⁻¹ in a 1 M H₂SO₄ electrolyte. Notably, a two-electrode device based on TPU-350 could generate the high energy density of 10.39 Kh kg⁻¹ at a power density of 50 W kg⁻¹ and maintain 91.12 % of its initial capacitance at the end of 10,000 cycles.