Porous carbon derived from Sunflower as a host matrix for ultra-stable lithium-selenium battery.

A novel porous carbon material using the spongy tissue of sunflower as raw material is reported for the first time. The obtained porous carbon has an extremely high surface area of 2493.0m2 g-1 , which is beneficial to focus on encapsulating selenium in it and have an inhibiting effect about diffusion of polyselenides over the charge/discharge processes used as the host matrix for Li-Se battery. The porous carbon/Se composite electrode with 63wt% selenium delivers a high specific capacitance of 319mAhg-1 of the initial capacity, and maintains 290mAhg-1 , representing an extremely high capacity retention of 90.9% after 840 cycles with the rate of 1C.