Dual-Salt-Induced Hierarchical Porous Structure in a Carbon Sheet for High Performance Supercapacitors
Xia Feng, Mengjiao Xu, Nannan Guo, Rui Ma, Lihua Yan, Leiming Cai, Dianzeng Jia, Lili Ai, Luxiang Wang
Abstract
Porous carbon, one of the characteristic materials for electrochemical energy storage devices, has been paid wide-ranging attention. However, balancing the reconcilable mesopore volume with a large specific surface area (SSA) was still a challenge. Herein, a dual-salt-induced activation strategy was developed to obtain a porous carbon sheet with ultrahigh SSA (3082 m 2 g –1 ), desirable mesopore volume (0.66 cm 3 g –1 ), nanosheet morphology, and high surface O (7.87%) and S (4.0%) content. Hence, as a supercapacitor electrode, the optimal sample possessed a high specific capacitance (351 F g –1 at 1 A g –1 ) and excellent rate performance (holding capacitance up to 72.2% at 50 A g –1 ). Furthermore, the assembled zinc-ion hybrid supercapacitor also exhibited superior reversible capacity (142.7 mAh g –1 at 0.2 A g –1 ) and highly stable cycling (71.2 mAh g –1 at 5 A g –1 after 10,000 cycles with retention of 98.9%). This work was delivered a new possibility for the development of coal resources for the preparation of high performance porous carbon materials.