Uniform Mesoporous MnO₂ Nanospheres as a Surface Chemical Adsorption and Physical Confinement Polysulfide Mediator for Lithium–Sulfur Batteries

Abstract

The actual implementation of lithium-sulfur batteries is hindered by inferior cyclic stability and poor coulombic efficiency stemming from the notorious shuttling of soluble polysulfide intermediates. Herein, uniform mesoporous MnO₂ nanospheres were prepared using a facile self-assembly and room-temperature reaction method. As a sulfur carrier of sulfur cathodes, the versatile architecture of MnO₂ not only provides powerful chemical adsorption to anchor polysulfide intermediates on the large polar surface area but also restrains them within the nanopores by physical confinement. The mesoporous MnO₂-stabilized sulfur cathode demonstrates a high initial reversible capacity of 1349.3 mA h g^-1 and a capacity fading rate of 0.073% at 1.0 C over 500 cycles. Furthermore, a reversible areal capacity of 2.5 mA h cm^-2 was achieved with stable cycling performance at a sulfur content of 80.7%. Our work offers a facile method to build efficient sulfur cathodes for high performance lithium-sulfur batteries.