Atomic-Scale Cryo-TEM Studies of the Electrochemistry of Redox Mediator in Li-O Batteries.

Rechargeable aprotic lithium (Li)-oxygen battery (LOB) is a potential next-generation energy storage technology because of its high theoretical specific energy. However, the role of redox mediator on the oxide electrochemistry remains unclear. This is partly due to the intrinsic complexity of the battery chemistry and the lack of in-depth studies of oxygen electrodes at the atomic level by reliable techniques.

Room Temperature Halide-Eutectic Solid Electrolytes with Viscous Feature and Ultrahigh Ionic Conductivity.

A viscous feature is beneficial for a solid electrolyte with respect to assembling solid-state batteries, which can change the solid-solid contacts from point to face. Here, novel halide-based deep eutectic solid electrolytes (DESEs) prepared by a facile ball milling method is reported. The mixture of halides triggers the deep eutectic phenomena by intermolecular interactions, leading to diverse morphologies and viscous statuses in terms of composition.

Enabling Long Cycle Life and High Rate Iron Difluoride Based Lithium Batteries by In Situ Cathode Surface Modification.

Metals fluorides (MFs) are potential conversion cathodes to replace commercial intercalation cathodes. However, the application of MFs is impeded by their poor electronic/ionic conductivity and severe decomposition of electrolyte. Here, a composite cathode of FeF and polymer-derived carbon (FeF @PDC) with excellent cycling performance is reported.

Promoting favorable interfacial properties in lithium-based batteries using chlorine-rich sulfide inorganic solid-state electrolytes.

The use of inorganic solid-state electrolytes is considered a viable strategy for developing high-energy Li-based metal batteries. However, suppression of parasitic interfacial reactions and growth of unfavorable Li metal depositions upon cycling are challenging aspects and not yet fully addressed. Here, to better understand these phenomena, we investigate various sulfide inorganic solid electrolytes (SEs), i.

Size-Dependent Chemomechanical Failure of Sulfide Solid Electrolyte Particles during Electrochemical Reaction with Lithium.

The very high ionic conductivity of LiGePS (LGPS) solid electrolyte (SE) makes it a promising candidate SE for solid-state batteries in electrical vehicles. However, chemomechanical failure, whose mechanism remains unclear, has plagued its widespread applications. Here, we report imaging lithiation-induced failure of LGPS SE.

In situ observation of cracking and self-healing of solid electrolyte interphases during lithium deposition.

The growth of lithium (Li) whiskers is detrimental to Li batteries. However, it remains a challenge to directly track Li whisker growth. Here we report in situ observations of electrochemically induced Li deposition under a CO atmosphere inside an environmental transmission electron microscope.

Ultrastable Anode/Electrolyte Interface in Solid-State Lithium-Metal Batteries Using LiCu Nanowire Network Host.

High interfacial resistance and uncontrollable lithium (Li) dendrite are major challenges in solid-state Li-metal batteries (SSLMBs), as they lead to premature short-circuiting and failure of SSLMBs. Here, we report the synthesis of a composite anode comprising a three-dimensional LiCu nanowire network host infiltrated with Li (Li* anode) with low interfacial impedance and superior electrochemical performance. The Li* anode is fabricated by dissolving Cu foil into molten Li followed by solidification.

In situ imaging electrocatalytic CO reduction and evolution reactions in all-solid-state Li-CO nanobatteries.

Li-CO batteries are promising energy storage devices owing to their high energy density and possible applications for CO capture. However, still some critical issues, such as high charging overpotential and poor cycling stability caused by the sluggish decomposition of LiCO discharge products, need to be addressed before the practical applications of Li-CO batteries. Exploring highly efficient catalysts and understanding their catalytic mechanisms for the CO reduction reaction (CORR) and evolution reaction (COER) are critical for the application of Li-CO batteries.

Unraveling the Reaction Mechanism of FeS as a Li-Ion Battery Cathode.

Iron pyrite (FeS) is a promising lithium-ion battery cathode material because of its low cost and ultrahigh energy density (1671 Wh kg). However, its reaction mechanisms are still controversial. In this work, we find that different from the conventional belief that an intermediate phase LiFeS is formed followed by Fe/LiS composites at the initial discharge, it undergoes a one-step reaction (FeS → Fe + LiS) or a two-step reaction (FeS → FeS + LiS → Fe + LiS), which depends on the current rate and temperature.