Mesoporous N-incorporated carbon with Ti single atom-regulated electronic structure as high performance cathodes for Li-S batteries

Lithium-sulfur (Li-S) batteries are considered as strong competitors for next-generation energy storage because of their high theoretical energy density. However, some challenges, such as shuttle effect of lithium polysulfides (LiPSs), volume expansion of sulfur during charge/discharge process and poor conductivity of the cathode, hindered their commercial application. In this paper, an excellent sulfur host material, the titanium single atom (TiSA)-anchored mesoporous N-incorporated carbon (TiSA-NC) was successfully obtained. The introduction of TiSAs onto the NC textures optimized their electronic structures including the charge distribution between the constituent atoms and the total density of states (TDOS) near the Fermi level. Consequently, the button battery constructed by TiSA-NC delivered impressive energy storage performance: a high reversible capacity of 1077 mAh·g⁻¹ at 0.1 C; an outstanding rate capacity of 541 mAh·g⁻¹ at 3 C; a superior long-term stability with a capacity fading rate of 0.053% per cycle for 500 cycles at 0.5 C. This work provided an effective strategy for manufacturing high performance Li-S batteries by designing and constructing single atom catalysts.