High-performance lithium–sulfur battery based on carbonized 3D MXene/T-CNF aerogel composite membrane

Lithium–sulfur batteries with high theoretical energy density are attracting more and more attention as candidate materials for next-generation energy storage systems. However, the insulating properties and poor shuttle effect of sulfur are still the main challenges faced by high-performance lithium–sulfur batteries. For this reason, we developed 3D MXene/T-CNF (three-dimensional Ti3C2Tx MXene/TEMPO-oxidized cellulose nanofibers) aerogel composite membrane by freeze-drying and high-temperature carbonization, which proved to be a good material for high-performance lithium–sulfur batteries. The MXene is a two-dimensional layered structure with high specific surface area and abundant active sites, which can provide electrodes with good conductivity and chemical stability as a supporting framework. Moreover, the addition of one-dimensional T-CNF strengthens the MXene structure and prevents it from collapsing while forming a three-dimensional conductive network, ensuring sufficient electron diffusion and electrolyte ion transportation channels. The material exhibits excellent electrochemical properties based on rational design. The 3D MXene/T-CNF-3 has an admirable reversible discharge specific capacity of 1119.6 mAh g−1 at the current density of 0.1 C, which is nearly 3 times as much as pure MXene. The Li–S battery exhibits good conductivity, rate performance, and cycle performance with the capacity retention of 99.4% after 200 cycles. This work offers a novel delicate design strategy for functional materials to achieve high-performance lithium–sulfur batteries.