ali rinaldi

Abstract: Hierarchical porous carbon anode and metal oxide cathode are promising for supercapacitor with both high energy density and high power density. This Letter uses NiO and commercial carbon nanotubes (CNTs) as electrode materials for electrochemical capacitors with high energy storage capacities. Experimental results show that the specific capacitance of the electrode materials for 10%, 30% and 50% CNTs are 279, 242 and 112 F/g, respectively in an aqueous 1 M KOH electrolyte at a charge rate of 0.56 A/g. The maximum specific capacitance is 328 F/g at a charge rate of 0.33 A/g.

Abstract: The Li-O2 system has been recognized as one of the candidates for next generation batteries. Several groups have reported Li-O2 cells with high capacity and good cycle stability [1-3]. However, there are also concerns about chemical and electrochemical reactions that occur during discharge and charge in different solvents and electrolytes [4-5]. In particular, the gradual formation of organic deposits as a result of the side reactions by the reactive superoxide radical O2.- and Li2O2 with the solvents can impede the discharge and charge reactions. The rates of both the main cathode reaction and the side reactions are influenced by composition and morphology of the cathode surface. The overall energy density of a Li-O2 cell is limited by the amount of solid Li2O2 formed at the cathode during discharge. Hence, it is important to understand if that amount only depends on structure and composition of the permanent cathode backbone (here: carbon), or if also its own growth history is relevant. In this work, we will demonstrate that the morphology of Li2O2 layers formed on carbon cathodes at the beginning of discharge vary in roughness when grown at increasing kinetically relevant overpotentials.

Abstract: Li-oxygen battery is expected to be the key player for powering electric vehicle. Experimental works have been performed to understand the mechanism and thus improve the performance of the oxygen reduction and the reverse reaction. However only small proportion in the literature are focused in the chemistry of the carbon cathode. In this presentation, the microstructure and surface properties of carbon cathode are investigated. The defect density of the bulk and surface of carbon materials were varied to test the performance of Li-Oxygen battery. The introduction of more defects on the carbon surface influence the performance of the Li-oxygen battery. More results will be shown at the meeting.