Hierarchical cellulose-derived carbon nanocomposites for electrostatic energy storage

The prob­lem of ener­gy stor­age and its con­tin­u­ous deliv­ery on demand needs new effec­tive solu­tions. Super­ca­pac­i­tors are viewed as essen­tial devices for solv­ing this prob­lem since they can quick­ly pro­vide high pow­er basi­cal­ly count­less num­ber of times. The per­for­mance of super­ca­pac­i­tors is most­ly depen­dent on the prop­er­ties of elec­trode mate­ri­als used for elec­tro­sta­t­ic charge accu­mu­la­tion, i.e. ener­gy stor­age. This study presents new sus­tain­able cel­lu­lose-derived mate­ri­als that can be used as elec­trodes for super­ca­pac­i­tors. Nanofi­brous car­bon nanofiber (CNF) mats were cov­ered with vapor-grown car­bon nan­otubes (CNTs) in order to get com­pos­ite CNF/​CNT elec­trode mate­r­i­al. The result­ing com­pos­ite mate­r­i­al had sig­nif­i­cant­ly high­er sur­face area and was much more con­duc­tive than pure CNF mate­r­i­al. The per­for­mance of the CNF/​CNT elec­trodes was eval­u­at­ed by var­i­ous analy­sis meth­ods such as cyclic voltam­me­try, gal­vano­s­ta­t­ic charge-dis­charge, elec­tro­chem­i­cal imped­ance spec­troscopy and cyclic sta­bil­i­ty. The results showed that the cel­lu­lose-derived com­pos­ite elec­trodes have fair­ly high val­ues of spe­cif­ic capac­i­tance and pow­er den­si­ty and can retain excel­lent per­for­mance over at least 2,000 cycles. There­fore it can be stat­ed that sus­tain­able cel­lu­lose-derived CNF/​CNT com­pos­ites are prospec­tive mate­ri­als for super­ca­pac­i­tor electrodes.