Porous hybrid aerogels with ultrahigh sulfur loading for lithium–sulfur batteries

Abstract

Owing to the outstanding superiority in energy density, lithium–sulfur (Li–S) batteries have great potential to become next-generation electrochemical energy storage systems. However, their practical applications are seriously limited by low utilization of active materials, rapid capacity attenuation, and poor rate performance. Herein, porous reduced graphene oxide and sulfur hybrid aerogel (RGA@S) cathode materials with various sulfur loadings (4.2 to 22.2 mg cm⁻²) have been designed and fabricated with a facile assembly strategy for Li–S batteries. Benefitting from the highly uniform distribution of sulfur, an ultrahigh mass specific capacitance (1386 mA h g⁻¹) and a superior areal specific capacitance of 25.86 (mA h cm⁻²) were achieved. In addition, with the employment of the stable interconnected porous structure of RGA@S electrodes, the redox reaction kinetics were efficiently modified, resulting in an improved rate performance. More importantly, the plentiful free spaces in RGA@S electrodes facilitate the adsorption of intermediate polysulfides within the cathode, realizing a long cycle life Li–S battery with an ultralow capacity fading upon 2000 cycles (0.013% per cycle).