Advanced lithium-sulfur battery leveraging carbonized MoO3/T-CNF Composite Aerogels

Lithium-sulfur (Li-S) battery is one of the most promising high energy density energy storage systems due to its high theoretical energy density (2600 W h kg^{− 1}) and specific capacity (1675 mA h g^{− 1}). However, the poor conductivity of elemental sulfur and discharge final products Li₂S₂/Li₂S, and the shuttle effect of lithium polysulfide are still important reasons for the capacity degradation of lithium-sulfur batteries. Herein, we propose to prepare MoO₃/T-CNF composite aerogel materials by compounding TEMPO-oxidized cellulose nanofibers (T-CNF) and molybdenum trioxide (MoO₃) nanosheets through ultrasonic dispersion, directional freeze drying and high-temperature carbonization processes. When used as the cathode material for lithium-sulfur batteries, the aerogel material offers high electrical conductivity, a well-developed pore structure, and a large specific surface area. These properties enable it to effectively adsorb polysulfides, suppress their shuttle effect, and alleviate the volume expansion of electrode materials during charge and discharge cycles. Among them, the highest specific discharge capacity of MoO₃/T-CNF-3 at 0.1C was 1721.8 mA h g^{− 1}, and the coulombic efficiency of 99.6% can still be maintained after 200 cycle. This demonstrates the benefits of the three-dimensional composite aerogel structure for Li-S battery cathode material applications, suggesting that the structural design of the material can enhance cycle stability while optimizing the specific capacity and multiplicative performance of Li-S batteries.