Synthesis of activated carbon nanospheres with hierarchical porous structure for high volumetric performance supercapacitors

• DOI: 10.1016/j.electacta.2015.10.016
• Publication Date: 2015-10-20T00:58:29Z
• Authors: Xiaoliang Yu; Jiamin Lu; Changzhen Zhan; Ruitao Lv; Qinghua Liang; Zheng-Hong Huang; Wanci Shen; Feiyu Kang
• Keywords: Gravimetric analysis; Carbon fibers; Horizontal scan rate; Power density

Abstract Activated carbon nanospheres (ACNS) with hierarchical porosity have been synthesized via a low-concentration hydrothermal reaction with phenolic resin as a carbon source and block copolymer F127 as a soft template, followed by subsequent KOH activation. As-obtained ACNS material integrates several advantages, such as a nanoscale particle size, a hierarchical porosity, abundant oxygen-containing functional groups and a high mass density (0.81 g cm−3). The electrochemical tests in KOH aqueous electrolyte shows superior capacitive performances, i.e. both high gravimetric and volumetric capacitance of 243 F g−1 and 198 F cm−3, a large areal capacitance of 25.5 μF cm−2, an excellent rate capability as well as a superior long-term cycling stability (96.1% capacitance retention over 10000 cycles). Moreover, symmetric supercapacitors based on ACNS electrodes achieve a high volumetric energy density of 6.0 Wh L−1, which maintains 3.7 Wh L−1 even at a high power density of 6.6 kW L−1. Such ACNS thus shows great potential as a promising porous carbon material for high volumetric performance supercapacitors.