Heteroelectrocatalyst for optimizing polysulfides in high-efficiency LiS batteries

Lithium‑sulfur (Li S) batteries are viewed as leading contender for future energy storage technologies, thanks to impressive energy density, extremely high theoretical capacity, abundant sulfur availability, and the inherently low reduction potential of lithium metal. These attributes make Li S batteries highly appealing for advanced energy storage applications. Nonetheless, despite their promising potential, the real-world application of Li S batteries is confronted with substantial obstacles. Foremost among these are the persistent shuttle effect of lithium polysulfides (LiPSs) at the sulfur cathode and the slow kinetics of sulfur reduction reactions, which together lead to poor rate performance and limited cycling stability. These issues significantly hinder their overall performance and commercial feasibility. Herein, a three-dimensional (3D) titanium-based heterostructure aerogel (MX-TiO 2 ) was prepared using a low-temperature hydrothermal method to serve as a sulfur host. Combining the adsorptive properties of TiO 2 with the catalytic capabilities of MXene, the MX-TiO 2 heteroelectrocatalyst facilitates seamless adsorption, diffusion, and conversion of polysulfides. When the heteroelectrocatalyst is used in the cathode, the corresponding Li S cell maintains a discharge capacity retention of approximately 63 % over 150 cycles at 0.5C. Notably, MX-TiO 2 as the cathode material with an augmented sulfur loading of 5.42 mg cm −2 , the S/MX-TiO 2 cathode exhibits a notable initial capacity of 6.23 mAh cm −2 at 0.2C. This work presents a method for designing high-performance 3D heteroelectrocatalyst that simultaneously boost the catalytic conversion of polysulfides while mitigating the shuttle effect, approaching as a promising strategy for working out the fundamental challenges regarding lithium‑sulfur batteries.