期刊
Battery Energy
标题
Density and porosity optimization of graphene monoliths with high mass-loading for high-volumetric-capacitance electrodes
作者
Dongliang Wang, Lizhi Sheng, Meihui Jiang, Xin Jin, Xinru Lin, Sang-Young Lee, Junyou Shi, Wenshuai Chen
摘要
Improving the volumetric capacitance of graphene materials for supercapacitors without sacrificing their rate capability, especially at high mass-loading, is a challenge because of the sluggish electrochemical kinetics of compact graphene electrodes. Here, a compact graphene monolith (dense graphene ribbons [DGRs]-0.6) was fabricated by using graphene oxide ribbons as building blocks and deliberately harmonizing the graphene primitive unit structure and interlayer spacing. The DGRs-0.6 contained abundant oxygen-containing functional groups and a highly interconnected pore structure, resulting in a large ion-accessible surface area, a high packing density, and fast electron/ion transport pathways. The DGRs-0.6 electrode exhibited a volumetric capacitance of 316 F cm–3, a rate capability of 220 F cm–3 at 100 A g–1, and ultralong cycling stability. For a mass loading of 11 mg cm−2, the DGRs-0.6 delivered volumetric capacitances of 150 F cm−3 at 1 A g−1 and 109 F cm−3 at 50 A g−1. The good rate capability and volumetric capacitance of DGRs-0.6 under high mass loading demonstrate its potential as a supercapacitor electrode for practical applications.
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