Effect of nanosized Mg0.6Ni0.4O prepared by self-propagating high temperature synthesis on sulfur cathode performance in Li/S batteries

Nanostructured magnesium nickel oxide Mg0.6Ni0.4O was successfully synthesized by self-propagating high temperature synthesis (SHS) followed by heat treatment. The effect of the precursor composition and calcination temperature on the Mg0.6Ni0.4O powder properties was investigated. These particles were used as an additive to prepare S/Mg0.6Ni0.4O composite via ball-milling with sulfur. The composite preparation conditions were optimized to achieve the higher specific surface area without compromising the sample crystallinity. The SEM observation revealed that the sulfur morphology was drastically changed by the Mg0.6Ni0.4O addition, from smooth to rough agglomerated particles. This change has enhanced the electrochemical performance of the composite cathode. Cyclic voltammetry and charge–discharge tests demonstrated enhanced reversibility and high sulfur utilization in a Li/S cell with S/Mg0.6Ni0.4O cathode, delivering about 850 mAh g− 1 of reversible capacity at the initial cycle. The effect of the Mg0.6Ni0.4O heat treatment temperature on the S/Mg0.6Ni0.4O cycling performance was also investigated. The cathode with Mg0.6Ni0.4O calcined at 700 °C exhibited enhanced capacity retention which could be due to its high specific surface area and nanosized structure.

Morphology difference between sulfur and sulfur/Mg0.6Ni0.4O leads to the difference in their electrochemical performance. The sulfur/Mg0.6Ni0.4O composite surface is rough and consists of agglomerated nanosized primary particles, which could be favorable for the cathode reactivity due to the active surface area increase.Figure optionsDownload as PowerPoint slideHighlights
► Mg0.6Ni0.4O was synthesized by self-propagating high temperature synthesis.
► Sulfur/Mg0.6Ni0.4O composite was prepared via ball milling.
► Novel morphology of the composite was achieved via Mg0.6Ni0.4O dispersion.
► Mg0.6Ni0.4O enhanced electrochemical performance of the lithium-sulfur batteries.