In Situ Phosphorization for Constructing Ni₅P₂‐Ni Heterostructure Derived from Bimetallic MOF for Li–S Batteries

Heterostructured materials commonly consist of bifunctions due to the different ingredients. For host material in the sulfur cathode of lithium‐sulfur (Li‐S) batteries, the chemical adsorption and catalytic activity for lithium polysulfides (LiPS) are important. This work obtains a Ni₅P₂‐Ni nanoparticle (Ni₅P₂‐NiNPs) heterostructure through a confined self‐reduction method followed by an in situ phosphorization process using Al/Ni‐MOF as precursors. The Ni₅P₂‐Ni heterostructure not only has strong chemical adsorption, but also can effectively catalyze LiPS conversion. Furthermore, the synthetic route can keep Ni₅P₂‐NiNPs inside of the nanocomposites, which have structural stability, high conductivity, and efficient adsorption/catalysis in LiPS conversion. These advantages make the assembled Li–S battery deliver a reversible specific capacity of 619.7 mAh g⁻¹ at 0.5 C after 200 cycles. The in situ ultraviolet‐visible technique proves the catalytic effect of Ni₅P₂‐Ni heterostructure on LiPS conversion during the discharge process.