Solid-state Li-O
2
batteries (SSLOBs) have attracted considerable attention because of their high energy density and superior safety. However, their sluggish kinetics have severely impeded their practical application. Despite efforts to design highly efficient catalysts, efficient oxygen reaction evolution at gas-solid interfaces and fast transport pathways in solid-state electrodes remain challenging. Here, we develop a dual electronic-ionic microenvironment to substantially enhance oxygen electrolysis in solid-state batteries. By designing a lithium-decorative catalyst with an engineering crystal structure, the coordinatively unsaturated sites and high concentration of defects alleviate the limitations of electronic-ionic transport in solid interfaces and create a balanced gas-solid microenvironment for solid-state oxygen electrolysis. This strategy facilitates oxygen reduction reaction, mediates the transport of reaction species, and promotes the decomposition of the discharge products, contributing to a high specific capacity with a stable cycling life. Our work provides previously unknown insight into structure-property relationships in solid-state electrolysis for SSLOBs.
Solid‐state lithium‐oxygen batteries (SSLOBs) offer high energy density with enhanced safety. However, the challenge of energy loss induced by the high polarization of the solid‐state air electrode has become a major bottleneck for its further development. Here, a homonuclear Fe‐Fe catalyst (Fe2‐N‐C) matched to reactants (Li2‐xO2, 0 ≤ x ≤ 2) size to alleviate the redox polarization in solid‐state electrodes is designed. Atomically resolved transmission electron microscopy reveals that the spatial size of Fe‐Fe clusters (1.5–2 Å) is commensurate with Li2‐xO2 (1.2–2.2 Å), which can overcome the challenges associated with catalyst/reactant size mismatch. In‐depth theoretical analyses show that orbital coupling and spin state jumping between Fe‐Fe sites allows the Fe centers to exhibit d‐orbital delocalization and high electronic spin states. These features enhance the activation of paramagnetic oxygen species, optimize the binding strength to LiO2 and reduce the charge/discharge voltage gap. Meanwhile, the size‐matching effect induces the ductile growth of the discharge product into a highly reversible film‐like morphology. The Fe2‐N‐C cathode with low overpotential exhibits significantly improved round‐trip efficiency (84.9%). The concept of this work opens up new opportunities for designing high‐performance SSLOBs.
A laboratory scale closed-loop cycle system for the complete regeneration of sodium persulfate/sulfuric acid etching solution (SPS) has been developed by anode oxidation of sulfate paired to cathode reduction of copper.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.