Layered double hydroxides used as the sulfur hosts for lithium-sulfur batteries and the influence of metal composition on their performance

The development of lithium-sulfur (Li–S) batteries is limited by the performance of the sulfur positive electrode. Using high-performance sulfur host materials such as layered double hydroxides (LDHs) to load sulfur is an effective way to improve the performance of the sulfur positive electrode. In this work, three popular LDHs (NiFe-LDH, NiAl-LDH, and ZnAl-LDH) with similar morphology and particle size are prepared and used as the sulfur hosts to evaluate their performance for loading of sulfur. It is found that the electrochemical performance of sulfur is enhanced to varying degrees after loading of sulfur on various LDHs. The metal composition of LDHs has a great influence on the electrochemical performance of sulfur on LDHs. NiFe-LDH shows better performance than other two LDHs after loading of sulfur because of the stronger interaction between Ni&Fe atoms and lithium polysulfides. In addition, NiFe-LDH shows good catalytic activity for the conversion of lithium polysulfides, which is also conductive to improve the electrochemical performance of sulfur. This study shows that the performance of LDHs used as the sulfur hosts can be further optimized by tuning their metal composition. Graphical Abstract