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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.

Abstract The viability of lithium‐sulfur (Li–S) batteries toward real implementation directly correlates with unlocking lithium polysulfide (LiPS) evolution reactions. Along this line, designing promotors with the function of synchronously relieving LiPS shuttle and promoting sulfur conversion is critical. Herein, the nitrogen evolution on hierarchical and atomistic Ni–N–C electrocatalyst, mainly pertaining to the essential subtraction, reservation and coordination of nitrogen atoms, is manipulated to attain favorable Li–S pouch cell performances. Such rational evolution behavior realizes the “nitrogen balance” in simultaneously regulating the Ni–N coordination environment, Ni single atom loading, abundant vacancy defects, active nitrogen and electron conductivity, and maximizing the electrocatalytic activity elevation of Ni–N–C system. With such merit, the cathode harvests favorable performances in a soft‐packaged pouch cell prototype even under high sulfur mass loading and lean electrolyte usage. A specific energy density up to 405.1 Wh kg−1 is harvested by the 0.5‐Ah‐level pouch cell.

Abstract The lithium polysulfides (LiPS) dissolution into electrolyte as well as consequent shuttle behavior seriously exacerbate the electrochemical performance of lithium–sulfur batteries. Herein, the intrinsic defect of graphene has been tailored by using plasma irradiation. The topological defective carbon structure is demystified into monovacancy and divacancy which effectively promote Li–S redox kinetics by selectively decelerating the generation of soluble high‐order LiPSs and passingly promoting the conversion to final solid products. Theoretical prediction uncovers the selective manipulation of Li–S redox kinetics by defective graphene, facilitating the reduced overpotential effect and uniform deposition of Li2S. Moreover, the divacancy presents a higher activity for Li–S chemistry in contrast with monovacancy. Therefore, the battery achieves superior cyclability with a capacity retention of 88.6% at 1.0 C over 300 cycles. Furthermore, it yields an areal capacity up to 8.5 mAh cm−2 with a sulfur loading of 13.3 mg cm−2.

Adding silica nanofiller in silicone rubber can toughen the matrix 3 orders in terms of fracture energy, which is far larger than most other nanofiller-rubber systems. To unveil the astonishing toughening mechanism, we employ in situ synchrotron radiation X-ray nanocomputed tomography (Nano-CT) technique with high spatial resolution (64 nm) to study the structural evolution of silica nanofiller in silicone rubber matrix at different strains. The imaging results show that silica nanofiller forms three-dimensional connected network, which couples with silicone chain network to construct a double-network structure. Stress-induced phase separation between silica nanofiller and silicone polymer chain networks is observed during tensile deformation. Unexpectedly, though the spatial position and morphology of nanofiller network changes greatly at large strains, the connectivity of nanofiller network shows negligible reduction. This indicates that nanofiller network undergoes destruction and reconstruction simultaneously, during which silica nanofiller serves as reversible high functionality cross-linker. The reversible bonding between silica nanofiller and silicone rubber or between nanofiller particles can dissipate mechanical energy effectively, which may account for the 3 orders enhancement of toughness. [ABSTRACT FROM AUTHOR]