A labyrinth-like network electrode design for lithium–sulfur batteries

Abstract

The volume expansion of sulfur and the dissolution of polysulfides into the electrolyte are the key issues to be solved in the development of lithium–sulfur batteries. In this work, a labyrinth electrode material design is presented to overcome these difficulties in lithium–sulfur batteries. The shell of NiO–Co₃O₄ hollow spheres as the “wall” to prevent the polysulfide dissolution cross-links into a labyrinth network as a sulfur host. The 3D labyrinth network not only provides enough inner space to load sulfur but also adapts to its large volume expansion during lithiation and delithiation. In addition, the polar NiO–Co₃O₄ shells can promote the chemical adsorption of polysulfides, while NiO–Co₃O₄ shells can promote the conversion of polysulfides into Li₂S. With this unique design, the 3D labyrinth-like NiO–Co₃O₄@S electrode presents a good electrochemical performance, delivering high capacity with a stable cycling life of up to 200 cycles at 1C and the attenuation rate of each cycle is only 0.1%.