Rational design of three-dimensional MXene-based aerogel for high-performance lithium–sulfur batteries

Lithium–sulfur (Li–S) battery with high energy density is attracting more and more attention as a candidate battery for high-energy power supply in the coming new energy era. However, several defects, such as the insulation properties and shuttle effect of sulfur species, greatly hinder its application. Herein, we rationally design a three-dimensional MXene-based aerogel with a surface area of 221 m 2 g –1 and use it as a sulfur host and functional separator for Li–S battery. In the preparation strategy of MXene-based aerogel, Ti 3 C 2 T x and melamine–formaldehyde resin are integrated into a three-dimensional interconnected porous network structure. As the sulfur host, MXene-based aerogel-derived sulfur cathode shows a highly reversible specific capacity of 1042 mA h g –1 at 0.1 C, excellent rate capability, and long-term cycling stability. Furthermore, the modified separator made by coating MXene-based aerogel on the commercial separator has been applied to Li–S battery. Compared with MXene modified separator, the rate capability and cycling performance of Li–S battery with the MXene-based aerogel modified separator are largely enhanced. Graphical abstract