Nano-Mg0.6Ni0.4O and mesoporous carbon composites for cycle-stability enhancement of lithium-sulfur batteries

A nano-magnesium nickel oxide-mesoporous carbon/sulfur composites (Mg0.6Ni0.4O-MPC/S) was designed and prepared for lithium-sulfur (Li-S) batteries. With a specific surface area as high as 1001.2 m2 g−1 and a unique porous structure, MPC in the composites can not only absorb the polysulfides generated during charge-discharge process to slow down the shuttle effect, but provide Li+ with a transmission channel. Nano-Mg0.6Ni0.4O (40 nm) particles, as an additive fabricated by self-propagating high temperature synthesis, can promote chemical bond dissociation with polysulfides and accelerate the electrochemical reaction rate. The composites loaded with 59 wt% sulfur exhibit a high initial capacity of 1360 mAh g−1 at 0.1 C and 695 mAh g−1 after 100 cycles, proving that the synergistic effect between MPC and nano-Mg0.6Ni0.4O leads to good cycle stability of the batteries.