Incomplete TiO2 coating assisted hosts to achieve multifunctional S-cathodes for lithium-sulfur battery.

To limit the shuttle effect in lithium-sulfur batteries (LSBs), a porous carbon microsphere with high specific surface area is prepared as sulfur hosts with an additional TiO 2 coating on the exterior of the host. The average thickness of the coating is about 4.4 nm, but some areas are too thin to fully cover the sulfur. With the progress of the charging and discharging, sulfur inside the shell will spill out of the shell but confined on the surface. Cracks on the electrode surface did not increase significantly after long cycles. And no obvious damage to the spherical structure of the active material can be observed. Benefiting from high stability and strong adsorption of TiO 2 coating, the electrode shows a high initial capacity of 888.16 mA h g−1 at 0.5 C, and 443.63 mA h g−1 after 1000 cycles. Even at charge-discharge rate of 1 C, it also delivers a high initial capacity of 691.32 mA h g−1, and 369.25 mA h g−1 after 1000 cycles. [ABSTRACT FROM AUTHOR]