Efficient and eco-friendly preparation of N/P/O co-doped porous carbon electrode for zinc-ion hybrid supercapacitors by laser carbonization

Abstract

The incorporation of heteroatoms into carbon materials confers advantages in the development of electrode materials for zinc-ion supercapacitors with superior electrochemical performance. However, the conventional carbonization process requires a large thermal power input and is characterized by complexity, high costs, and lengthy reaction times. In this work, the phytic acid-doped polypyrrole (P-PPy) was carbonized via laser irradiation to synthesize N, P, O co-doped porous carbon (P-NOPC), wherein phytic acid served as the source of phosphorus and oxygen, while PPy served as the porous carbon precursor and nitrogen source. The formation of porous carbon can provide a large specific surface area for ion adsorption. The doping of heteroatoms improves the hydrophilicity of porous carbon electrodes and also improves the chemisorption capacity of carbon materials. The aqueous zinc-ion hybrid supercapacitor (ZHSC) based on 0.6P-NOPC9 positive electrode and zinc foil negative electrode has a discharge capacity of 148.0 mAh g−1 in a voltage window of 0.2–1.8 V at 0.1 A g−1, a high energy density (118.2 Wh kg−1) and long cycle life (capacity retention of 98.5% after 10,000 cycles). In addition, the capacity retention of the flexible quasi-solid-state ZHSC is 97.8% after 10,000 cycles. This study can provide a reference for the feasible design of porous carbon electrodes with high performance.