The aprotic lithium-oxygen (Li-O2) battery has triggered tremendous efforts for advanced energy storage due to the high energy density. However, realizing toroid-like Li2O2 deposition in low-donor-number (DN) solvents is still the intractable obstruction. Herein, a heterostructured NiS2/ZnIn2S4 is elaborately developed and investigated as a promising catalyst to regulate the Li2O2 deposition in low-DN solvents. The as-developed NiS2/ZnIn2S4 promotes interfacial electron transfer, regulates the adsorption energy of the reaction intermediates, and accelerates O-O bond cleavage, which are convincingly evidenced experimentally and theoretically. As a result, the toroid-like Li2O2 product is achieved in a Li-O2 battery with low-DN solvents via the solvation-mediated pathway, which demonstrates superb cyclability over 490 cycles and a high output capacity of 3682 mA h g-1. The interface engineering of heterostructure catalysts offers more possibilities for the realization of toroid-like Li2O2 in low-DN solvents, holding great promise in achieving practical applications of Li-O2 batteries as well as enlightening the material design in catalytic systems.
Keywords: Li−O2 batteries; cathode catalysts; electron transfer; heterostructure engineering; intermediate solubility.