Synthesis of C/MoS2-CoMo2S4 for application in Li-O2 batteries

High efficiency electrocatalyst is the key factor to achieve high charge-discharge specific capacity and long cycle life of Li-O2 batteries (LOBs). In this work, the C/MoS2CoMo2S4 was successfully prepared by calcining the hybrid of ZIF-67 and C/MoS2 at 800 °C. The composite materials have three advantages for oxygen reduction and evolution reaction (ORR/OER) of LOBs, including highly efficient catalysis of CoMo2S4, abundant porous network and a surface conducive to Li2O2 precipitation. The LOBs with acid-pickled C/MoS2CoMo2S4–800 showed a high discharge specific capacity (17,551 mAh g−1) and an excellent cycle stability of 336 cycles at a current density of 500 mA g−1 and capacity limit of 1000 mAh g−1. Interestingly, the catalytic activity of C/MoS2CoMo2S4 can be improved by acid pickling or the increasement of calcination temperature from 700 to 800 °C.