Tailoring performance of hybrid supercapacitors by fluorine-rich block copolymer-derived carbon coated mixed-phase TiO2 nanoparticles
Journal of Alloys and Compounds(2023)
摘要
Hybrid supercapacitors can function as both batteries and supercapacitors owing to their high specific energy and capacitive power, respectively. Transition metal oxide-based electrodes exhibit a high theoretical specific capacitance, but their large-scale application in charge storage devices is limited by their low conductivity and electrical stability. To address this problem, we introduced a highly conductive carbon coating over mixed-phase titanium dioxide (C/TiO2) using a novel carbon-rich polyacrylonitrile block copolymer containing an active pentafluorophenyl acrylate ester block (PAN-b-PFPA). The LiFePO4 (LFP) positrode and C/TiO2 negatrode assembled hybrid LFP║C/TiO2 @ 800 supercapacitor exhibited a high specific capacitance of 227 F/g (current density of 1 A/g), power density of 500 W/kg, and energy density of 32 W h/kg. Importantly, higher specific capacitance (∼84%) and Coulombic efficiency (∼96%) were maintained over 5000 charge–discharge cycles. The improved performance of hybrid LFP║C/TiO2 @ 800 supercapacitor is attributable to (1) selectively mixed anatase–rutile TiO2 phases that led to additional Ti3+ oxidation state formation, (2) firm porous carbon coating resulting from the surface anchoring of PAN-b-PFPA copolymer, and (3) fluorine/sulfur impurities from pyrolysis residues. The carbon coating of transition metal oxides from the pyrolysis of PAN-b-PFPA copolymers can facilitate the large-scale development of energy storage materials.
更多查看译文
关键词
hybrid supercapacitors,nanoparticles,tio2,fluorine-rich,copolymer-derived,mixed-phase
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要