Indium-based MOFs and carbon nanotube embedded efficient cathodes for high-performance lithium-sulfur batteries

Metal–organic frameworks (MOFs) exhibit great potential for lithium-sulfur (Li–S) batteries because of their unique characteristics such as the high surface area, the precise structure, and the tunable porous environment. However, their low binding energy with sulfur and poor absorbability of polysulfides leads to the “shuttle effect,” reducing the stability of MOFs. With strong bonding ability to sulfur, indium-based MOFs, in which the indium (In) shows the Lewis acid character, can form the stable chemical bonds of In-S. Based on it, we used the indium-based MOF-CPM-200 as a carrier, combined with the conductive multi-walled carbon nanotubes (CNT) and sulfur to construct the composite cathode material of CPM-200/CNT@S. The unique composite structure for cathode materials of Li–S batteries can inhibit the “shuttle effect” and enhance conductivity. The initial discharge capacity of the CPM-200/CNT@S can reach as high as 1400 mAh∙g−1 and maintain a capacity of about 840 mAh∙g−1 after 100 charge–discharge cycles at 0.1 C, the coulombic efficiency approaches 100%. This work offers a new strategy for constructing the MOFs-based cathode materials for Li–S batteries with high performance.