Carbon Nanotubes and CoNiO Nanoparticle-Modified Porous Metal Oxide as an Efficient Sulfur Host for Advanced Lithium–Sulfur Batteries

Abstract

Rational design of a porous sulfur host material is important to mitigate the lithium polysulfide (LiPS) shuttle effect in lithium–sulfur (Li–S) batteries. In this study, a three-dimensionally ordered macropore N-doped TiO₂ embedded with dense carbon nanotubes and CoNiO nanoparticles (CNT/CoNiO@N–TiO₂) is prepared as a sulfur host material. This porous structured metal oxide N–TiO₂ framework offers good structural stability and polarity toward LiPS accommodation and adsorption. The in situ-grown CNT within the porous N–TiO₂ provides a physical barrier for the LiPS migration and benefits the conductivity of the host material. Furthermore, the embedded CoNiO nanoparticles have high synergistic catalytic activity for the LiPS conversion. Accordingly, the sulfur-loaded CNT/CoNiO@N–TiO₂ host achieves a high initial capacity of 1004 mA h g^–1 at 0.2 C and excellent cycling performance with a capacity decay of 0.047% per cycle in 500 cycling test at 1.0 C. This work provides an effective strategy for the design of metal oxide-based sulfur host materials in Li–S batteries.