Facile fabrication of N-self-doped porous carbons from green solid waste for supercapacitors with high cycling stability and flexibility. (December 2022)

• Record Type: Journal Article
• Authors: Hao, Ruonan; Ma, Ruining; Cao, Yali; Zhou, Wanyong; Chai, Hui
• Is Part Of: Materials today communications. Volume 33(2022)
• Publication Date: 2022-12
• Subjects: Biomass -- Self-doped -- Porous carbon materials -- All-solid-state symmetrical supercapacitors; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2022.104911
• Languages: English
• ISSNs: 2352-4928

Abstract

Abstract: Carbon has become a commercial electrode material for supercapacitors. From the viewpoint of sustainable development, biochar is a superior electrode material for supercapacitors. Therefore, the synthesis of supercapacitor layered interconnected porous carbon materials with excellent electrochemical performance from biomass solid wastes has become a research hotspot. This paper reports the preparation of sunflower straw-based porous carbon (SSPC) materials with good pore size distribution, self-doped nitrogen and oxygen, and microporous/mesoporous structure using HCOOK as a new-type activator. In the three-electrode system, the capacitance of the optimal sample SSPC600–4 was maintained at 230 F g −1 under a high current density of 100 A g −1 . The symmetrical supercapacitor had the highest energy density of 25 Wh kg −1 (500 W kg −1 ) and excellent cycle stability (96.21% capacity after 20, 000 cycles). In addition, the all-solid-state symmetrical supercapacitors showed flexibility and successfully powered five 3 V bulbs when connected in series, thus confirming their potential applications in portable and wearable devices. Graphical Abstract: Using waste sunflower straw as raw material, potassium formate (HCOOK) as a new non-toxic activator, nitrogen and oxygen self-doped layered porous carbon material was prepared by one-step activation carbonization method. The electrochemical measurements demonstrate that nitrogen and oxygen self-doped layered porous carbon material have excellent electrochemical performance for supercapacitor. ga1 Highlights: High-performance nitrogen and oxygen self-doped porous activated carbon are prepared with sunflower straw as precursor. Excellent electrochemical properties of nitrogen and oxygen self-doped porous activated carbon are achieved with optimum specific capacitance of 346 F g -1 at the current density of 1 A g -1 . The all-solid-state symmetrical supercapacitors device shows high flexibility and high energy density.