Heteroatom-doped Ginkgo Folium porous carbon modified separator for high-capacity and long-cycle lithium-sulfur batteries

Alleviating the shuttle effect is the core issue to realizing the practical application of lithium-sulfur battery (Li-S battery). In this study, heteroatom-doped Ginkgo Folium porous carbon (HDGF) was synthesized. The HDGF has micro-mesoporous composite structure, super large specific surface area, and excellent electrical conductivity. Attractively, HDGF-modified separator forms a unique 3D porous structure, which improves the affinity with electrolyte and accelerates the transport of Li+. Coupled with the strong chemical adsorption of polysulfides by heteroatoms, the battery exhibits excellent performance. The battery with the HDGF separator can reach discharge capacity of 1150 mAh/g at 0.5C and with only 0.094 % attenuation rate of capacity per cycle after 500 cycles. Even at high sulfur loading (3.32 mg cm−2), the discharge capacity is 860.6 mAh/g after cycling 120 cycles at a current density of 0.5C. Furthermore, using in-situ Raman tests, the evolution and shuttle mechanism of polysulfides were probed, and the efficient limitation of polysulfides by HDGF was demonstrated. This work enriches the exploration of biomass carbon in separators and provides an inexpensive solution for the practical application of Li-S batteries.