High Energy Density and Stable Three-Dimensionally Structured Se-Loaded Bicontinuous Porous Carbon Battery Electrodes

3D-structured Se-loaded bicontinuous porous carbon (BPC) electrodes are fabricated through colloidal templating of BPC followed by pulsed-voltage Se electrodeposition. The resultant electrodes are found to deliver a specific capacity of 665 mAh g⁻¹ at a rate of 0.1 C, near the theoretical value for Se. When a vinylene carbonate (VC) containing electrolyte is utilized, the capacity fade over 500 cycles at 1 C rate is as small as a few percent. Impedance measurements and physical characterization of cycled electrodes indicate the exceptionally stable cycling performance is possibly due to VC resulting in the formation of a stable solid electrolyte interface (SEI) during cycling. Along with the cycling stability, the rate performance of the 3D Se/BPC electrodes is also good. Due to the bicontinuous structure of carbonaceous current collector at rates as high as 5 C, the deliverable capacity is about 300 mAh g⁻¹.