Electron-injection-induced tensile lattice strain in hierarchically porous Ni@O-doped carbon nanocage/CNTs sponge for enhanced electrocatalytic reduction of Li2S2 to Li2S

This effectively reduces the energy barrier for the Li2S2 → Li2S conversion, with an apparent activation energy of 24.69 kJ mol-1 for the reduction reaction on Ni@OCN, which is 39.97 kJ mol-1 lower than that of pure carbon. Benefiting from this kinetic acceleration mechanism, the cell assembled with Ni@OCN/OCNTS delivers a high initial specific capacity of 1574.6 mAh g-1 at 0.2 C. Even under a sulfur loading of 3.9 mg cm-2 and a high rate of 1 C, an initial specific capacity of 812 mAh g-1 can still be achieved.

This work elucidates the synergistic catalytic mechanism between transition metal nanoparticles and heteroatom-doped carbon carriers from the perspective of “lattice strain catalysis”, providing a new theoretical basis and material paradigm for designing high-performance catalysts for practical lithium-sulfur batteries.