Figure 5: Electrochemical properties of the G–SeHMs as cathode materials for applications in lithium–selenium batteries.

(a) Cyclic voltammograms at a scan rate of 0.1 mV s−1. Galvanostatic charge/discharge profiles of the G–SeHMs (top; black), Se–RGO–CB physical mixture (middle; blue) and Se–CB physical mixture (bottom; red) as control samples for comparison at a current density of 67.5 mA g−1, corresponding to a rate of 0.1 C. (c) Comparative study of cycling performance and Coulombic efficiencies of the G–SeHMs (black), Se–RGO–CB physical mixture (blue) and Se–CB physical mixture (red) after 100 cycles at 0.1 C. (d) Rate capabilities of the G–SeHMs at rates of 0.1–5 C.