RESUMO
Multilayer nanospheres with alternating 2H-MoS2 and C layers were studied as a cathode base for lithium power sources. Interesting hierarchical structure, synergetic effect, and the presence of defects as supplementary active sites, introduced by the additional annealing at 773 K in Ar atmosphere, have determined the conductivity, referred to symmetric hopping or random barrier model, and led to achieve the high values of specific capacity of 3700, 1390, and 790 A h kg(-1) at currents 0.1, 0.3, and 0.5 C. Such unusual result was never reported before and could be explained by combining of the faradaic and non-faradaic accumulation processes within electrode material.
RESUMO
The results of electrochemical studies of nanoporous carbon as electrode material for electrochemical capacitors (EC) are presented in this work. Nanoporous carbon material (NCM) was obtained from the raw materials of plant origin by carbonization and subsequent activation in potassium hydroxide. It is established that there is an optimal ratio of 1:1 between content of KOH and carbon material at chemical activation, while the maximum specific capacity of NCM is 180 F/g. An equivalent electrical circuit, which allows modeling of the impedance spectra in the frequency range of 10(-2) to 10(5) Hz, is proposed, and a physical interpretation of each element of the electrical circuit is presented.
