960化工网
Structure-guided Capacitance Relationships in Oxidized Graphene Porous Materials Based Supercapacitors
SrinivasGadipelli,HaniehAkbari,JuntaoLi,ChristopherA.Howard,HongZhang,PaulR.Shearing,DanJ.L.Brett
Energy & Environmental Materials Pub Date : 05/17/2023 00:00:00 , DOI:10.1002/eem2.12637
Abstract
Supercapacitors formed from porous carbon and graphene-oxide (GO) materials are usually dominated by either electric double-layer capacitance, pseudo-capacitance, or both. Due to these combined features, reduced GO materials have been shown to offer superior capacitance over typical nanoporous carbon materials; however, there is a significant variation in reported values, ranging between 25 and 350 F g−1. This undermines the structure (e.g., oxygen functionality and/or surface area)-performance relationships for optimization of cost and scalable factors. This work demonstrates important structure-controlled charge storage relationships. For this, a series of exfoliated graphene (EG) derivatives are produced via thermal-shock exfoliation of GO precursors and following controlled graphitization of EG (GEG) generates materials with varied amounts of porosity, redox-active oxygen groups and graphitic components. Experimental results show significantly varied capacitance values between 30 and 250 F g−1 at 1.0 A g−1 in GEG structures; this suggests that for a given specific surface area the redox-active and hydrophilic oxygen content can boost the capacitance to 250–300% higher compared to typical mesoporous carbon materials. GEGs with identical oxygen functionality show a surface area governed capacitance. This allows to establish direct structure-performance relationships between 1) redox-active oxygen functional concentration and capacitance and 2) surface area and capacitance.
平台客服
平台客服
平台在线客服