writer：Fen Ran* Xuanxuan Zhang, Yongtao Tan, Lingbin Kong,Long Kang, Changan Xu and Shaowei Chen*
keywords：carbon microcapsules, supercapacitor
source：期刊
specific source：RSC Advances
Issue time：2015年

Remarkable supercapacitor electrodes with a high specific supercapacitance and a super long cycle life

were achieved by using hierarchical porous hollow carbon microcapsules (HPHCMs) as active materials.

HPHCMs were prepared by a facile chemical route based on pyrolysis of a soft sacrificial template

involving a non-crosslinked core of poly(styrene-r-methylacrylic acid) and a crosslinked shell of

poly(styrene-r-divinylbenzene-r-methylacrylic acid), which were synthesized by using traditional radical

polymerization and emulsion polymerization. The results of scanning electron microscopy, transmission

electron microscopy and Brunauer–Emmett–Teller characterizations revealed that HPHCM possessed

the desired pore structure with apparent macro-/meso- and micropores, which not only provided

a continuous electron-transfer pathway to ensure good electrical contact, but also facilitated ion

transport by shortening diffusion pathways. As electrode materials for supercapacitor, a high specific

capacitance of 278.0 F g
1 was obtained at the current density of 5 mA cm
2. Importantly, after 5000

potential cycles in 2 M KOH electrolyte at the discharge current density of 20 mA cm
2, the capacitance

actually increased from 125 to 160 F g
1 and then remained 151 F g
1, corresponding to a capacitance

retention of 120%, likely due to electrochemical self-activation