Electrocatalytic Mechanism and Sabatier Principle in CN-Supported Atomically Dispersed Catalysts for the Sulfur Reduction Reaction in Lithium-Sulfur Batteries.

The sluggish kinetics of the sulfur reduction reaction (SRR) impedes the practical application of lithium-sulfur batteries (LSBs). Electrocatalysts are necessary to expedite the conversion of polysulfides. Here, we systematically investigate the chemical mechanisms and size dependence of catalytic activities toward the SRR from LiS to LiS on single-, double-, and triple-atom catalysts supported on CN (M@CN, where M is a 3d transitional metal and = 1-3) as model systems by using first-principles calculations and a comprehensive electrocatalytic model.

Revisiting the Role of Physical Confinement and Chemical Regulation of 3D Hosts for Dendrite-Free Li Metal Anode.

Lithium metal anode has been demonstrated as the most promising anode for lithium batteries because of its high theoretical capacity, but infinite volume change and dendritic growth during Li electrodeposition have prevented its practical applications. Both physical morphology confinement and chemical adsorption/diffusion regulation are two crucial approaches to designing lithiophilic materials to alleviate dendrite of Li metal anode. However, their roles in suppressing dendrite growth for long-life Li anode are not fully understood yet.

Role of the Metal Atom in a Carbon-Based Single-Atom Electrocatalyst for LiS Redox Reactions.

Carbon-based single metal atom catalysts (SACs) are being extensively investigated to improve the kinetics of the Li-S redox reaction, which is greatly important for batteries with cell-level energy densities >500 W h kg . However, there are contradictory reports regarding the electrocatalytic activities of the different metal atoms and the role of the metal atom in LiS chemistry still remains unclear. This is due to the complex relationship between the catalytic behavior and the structure of carbon-based SACs.

Cobalt in Nitrogen-Doped Graphene as Single-Atom Catalyst for High-Sulfur Content Lithium-Sulfur Batteries.

Because of their high theoretical energy density and low cost, lithium-sulfur (Li-S) batteries are promising next-generation energy storage devices. The electrochemical performance of Li-S batteries largely depends on the efficient reversible conversion of Li polysulfides to LiS in discharge and to elemental S during charging. Here, we report on our discovery that monodisperse cobalt atoms embedded in nitrogen-doped graphene (Co-N/G) can trigger the surface-mediated reaction of Li polysulfides.