In-situ embedding CoTe catalyst into 1D–2D nitrogen-doped carbon to didirectionally regulate lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have been widely investigated attributed to their advantages of high energy density and cost effectiveness. However, it is still limited by the uncontrolled shuttle effect of the sulfur cathode and the promiscuous dendrite growth over the lithium anode. To handle the above issues, the highly conductive CoTe catalyst is precisely loaded onto nitrogen-doped nanotube and graphene-like carbon (CoTe⊂NCGs), which is employed as a bi-functionally integrated host. On the lithium anode, the CoTe⊂NCGs with excellent lithiophilic property effectively regulate the uniform deposition of lithium and achieve the effect of suppressing the disorderly growth of lithium dendrites. On the sulfur cathode, the electrochemical conversion of lithium polysulfides (LiPSs) is catalyzed to mitigate the notorious shuttle effect. In view of the bifunctionality of CoTe⊂NCGs, the assembled full cell can be steadily stable even for 800 cycles at a high rate of 2 C, and the capacity decay rate is only 0.05% per cycle. The areal capacity of 6.0 mAh·cm−2 is well retained after 50 cycles under the conditions of high sulfur loading, poor electrolyte (a low electrolyte-to-sulfur ratio, E/S = 4.2), and low negative to positive capacity ratio (N/P=1.6:1).