A rational template carbonization method for producing highly porous carbon for supercapacitor application

A rational template carbonization method has been implemented to produce nanoporous carbon as high performance supercapacitor electrode material. Sodium carboxymethyl cellulose (NaCMC) acts as carbon source, and inexpensive Mg(OAc)2·4H2O and Zn(OAc)2·2H2O as templates. It reveals that the carbonization temperature and the mass ratio of NaCMC, Mg(OAc)2·4H2O and Zn(OAc)2·2H2O are crucial for determining the carbon structure. The NaCMC-Mg-Zn-1:5:0.5 sample displays highly porous structure with large surface area (1596m2g−1), pore volume (5.93cm3g−1) and hierarchical pore size distribution. The carbon sample is measured in a two/three-electrode system, respectively. It has a high specific capacitance of 428.4Fg−1 at 1Ag−1, together with nice cycling durability. A high energy density up to 68.6Whkg−1 can be achieved as the power density of 1.5kWkg−1. The templates used in this work are cheap, commercially available and this template carbonization method, especially without any activation process, can be readily extended to prepare other kinds of nanoporous carbon.