Chlorine bridge bond-enabled binuclear copper complex for electrocatalyzing lithium–sulfur reactions

Abstract

Engineering atom-scale sites are crucial to the mitigation of polysulfide shuttle, promotion of sulfur redox, and regulation of lithium deposition in lithium–sulfur batteries. Herein, a homonuclear copper dual-atom catalyst with a proximal distance of 3.5 Å is developed for lithium–sulfur batteries, wherein two adjacent copper atoms are linked by a pair of symmetrical chlorine bridge bonds. Benefiting from the proximal copper atoms and their unique coordination, the copper dual-atom catalyst with the increased active interface concentration synchronously guide the evolutions of sulfur and lithium species. Such a delicate design breaks through the activity limitation of mononuclear metal center and represents a catalyst concept for lithium–sulfur battery realm. Therefore, a remarkable areal capacity of 7.8 mA h cm−2 is achieved under the scenario of sulfur content of 60 wt.%, mass loading of 7.7 mg cm−2 and electrolyte dosage of 4.8 μL mg−1.