Ultra-stable lithium-sulfur batteries using nitrogen-doped porous carbon nanosheets implanted with both Fe and Ni

The major problem with lithium-sulfur (Li-S) batteries is their poor cycling stability because of slow redox kinetics in the cathode and the growth of lithium dendrites on the anode. We report the production of 2D porous carbon nanosheets doped with both Fe and Ni (Fe/Ni-N-PCNSs) by an easy and template-free approach that solve this problem. Because of their ultrathin porous 2D structure and uniform distribution of Fe and Ni dopants, they capture polysulfides, speed up the sulfur redox reaction, and improve the material’s lithiophilicity, greatly suppressing the shuttling of polysulfides and dendrite growth on the lithium anode. As a result, it has an exceptional performance as a stable host for elemental sulfur and metallic lithium, producing a record long life of 1000 cycles with a very small capacity decay of 0.00025% per cycle in a Li-S battery and an excellent cycling stability of over 850 h with a small overpotential of >72 mV in a lithium metal battery. This work suggests the use of multifunctional-based 2D porous carbon nanosheets as a stable host for both elemental sulfur and metallic lithium to improve the Li-S battery performance.