One-Pot Synthesized Amorphous Cobalt Sulfide With Enhanced Electrochemical Performance as Anodes for Lithium-Ion Batteries

In order to solve the poor cycle stability and the pulverization of cobalt sulfides electrodes, a series of amorphous and crystalline cobalt sulfides were prepared by one-pot solvothermal synthesis through controlling the reaction temperatures. Compared to the crystalline cobalt sulfide electrodes, the amorphous cobalt sulfide electrodes exhibited superior electrochemical performance. The high initial discharge and charge capacities of 2,132 mAh/g and 1,443 mAh/g at 200 mA/g were obtained. The reversible capacity was 1,245 mAh/g after 200 cycles, which is much higher than the theoretical capacity. The specific capability was 815 mAh/g at 800 mA/g and increased to 1,047 mAh/g when back to 100 mA/g, indicating the excellent rate capability. The outstanding electrochemical performance of the amorphous cobalt sulfide electrodes could result from the unique characteristics of more defects, isotropic nature, and the absence of grain boundaries for amorphous nanostructures, indicating the potential application of amorphous cobalt sulfide as anodes for lithium-ion batteries.

A Facile Synthesis of PbS-G QDs Nanocomposite as Electrode Material With Enhanced Energy Density for High Performance Supercapattery Application

Bare PbS QDs and PbS-GQDs nanocomposite were prepared by chemical methods for supercapattery application and characterized by suitable analytical techniques confirming the formation of PbS-GQDs nanocomposite. The electrochemical performance of the fabricated electrodes showed that the PbS-GQDs nanocomposite exhibited high specific capacity, energy and power densities of 577.94 C g-1 , 166.45 Wh kg-1 and 576.01 W kg-1 respectively at 2 A g-1 compared to that of bare PbS QDs. The enhanced electrochemical performance of PbS-GQDs can be associated with the conductive platform provided by synergistic effect of GQDs. The nonlinearity in charge and discharge curves confirms the supercapattery behaviour of the nanocomposite. Also, PbS-G QDs nanocomposite electrode showed highly cyclic stability compared to bare PbS QDs after 5000 cycles. The results emphasize the potential of PbS-G QDs nanocomposite as a stable active electrode material for energy storage application.