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Doped ceria electrolytes are the state of the art low‐temperature solid oxide electrolytes because of their high ionic conductivity and good material compatibility. However, cerium tends to reduce once exposed to reducing environments, leading to an increase in electronic conduction and a decrease in efficiency. Here, the leakage current is mitigated in ceria‐based electrolytes by controlling the defect chemistry through an engineered cathode side microstructure. This functional layer effectively addresses the problematic electronic conduction issue in ceria‐based electrolytes without adding significant ohmic resistance and increases the ionic transference tO2−$t_{{{\mathrm{O}}}^{2 - }}$ number to over 0.93 in a thin 20 µm ceria‐based electrolyte at 500 °C, compared to a tO2−$t_{{{\mathrm{O}}}^{2 - }}$ of 0.8 for an unmodified one. Based on this design, solid oxide fuel cells (SOFCs) are further demonstrated with the remarkable peak power density of 550 mW at 500 °C and excellent stability for over 2000 h. This approach enables a potential breakthrough in the development of ceria‐based low‐temperature solid oxide electrolytes. [ABSTRACT FROM AUTHOR]

Utilizing tape casting–laminating–sintering technique, we developed a three‐dimensional (3D) porous–dense–porous trilayered Li–garnet framework that enables symmetric cycling lithium metal under high current densities for long time (∼3–10 mA/cm2 for over ∼500 h). To address the reasons that such 3D Li–garnet framework can withhold high current density and long‐term cycling, both experiments (nanoindentation and bending) and simulations (finite element analysis [FEA]) regarding mechanical properties on such 3D framework were employed. The results indicate that (1) the dense layer has high and uniform elastic modulus and hardness so can efficiently prevent lithium penetration and dendrites growth; (2) the porous layer, including the grains and the necking regions, has high nanomechanical properties to withhold the lithium penetration stress; (3) the spherical pores in the porous layer can withhold higher lithium penetration forces/stress compared with rectangular/regular pores based on FEA. The flexural strength of the whole structure was also characterized using the three‐point bending method to demonstrate the high strength (∼30.8–42.1 MPa) of the 3D framework. A rule‐of‐mixtures model was developed, which can be used to estimate the flexural strength of the trilayered framework based on the microstructures. Correlations between the mechanical properties and the high‐rate cycling are further discussed. [ABSTRACT FROM AUTHOR]

The full electrification of transportation will require batteries with both 3–5× higher energy densities and a lower cost than what is available in the market today. Energy densities of >1000 W h kg−1 will enable electrification of air transport and are among the very few technologies capable of achieving this energy density. Limetal–O2 or Limetal–air are theoretically able to achieve this energy density and are also capable of reducing the cost of batteries by replacing expensive supply chain constrained cathode materials with "free" air. However, the utilization of liquid electrolytes in the Limetal–O2/Limetal–air battery has presented many obstacles to the optimum performance of this battery including oxidation of the liquid electrolyte and the Limetal anode. In this paper a path towards the development of a Limetal–air battery using a cubic garnet Li7La3Zr2O12 (LLZ) solid-state ceramic electrolyte in a 3D architecture is described including initial cycling results of a Limetal–O2 battery using a recently developed mixed ionic and electronic (MIEC) LLZ in that 3D architecture. This 3D architecture with porous MIEC structures for the O2/air cathode is essentially the same as a solid oxide fuel cell (SOFC) indicating the importance of leveraging SOFC technology in the development of solid-state Limetal–O2/air batteries. [ABSTRACT FROM AUTHOR]

This document is a discussion from the journal Faraday Discussions on the topic of metal anodes and protected interfaces in lithium-oxygen batteries. The participants discuss various aspects of battery performance, including the use of lithium peroxide in the anode, the stability of materials against water and carbon dioxide, the deposition of lithium on copper electrodes, and the impact of depth of discharge and current density. They also discuss the fabrication of pinhole-free LLZO membranes and the use of ceramic electrolytes. The researchers have made observations on metal ion migration, short circuit formation, and the compatibility of LLZO with different liquid electrolytes. They have disclosed their conflicts of interest. [Extracted from the article]

This document is a discussion from the journal Faraday Discussions about materials for stable metal-oxygen battery cathodes. The discussion covers various topics such as the role of oxygen crossover in creating the solid electrolyte interface, the redox reactions of the iodide/triiodide couple, the effect of electrolyte composition on redox processes, the source of side reactions in the battery, the role of ionic liquids in changing product morphology, and the importance of water content in electrode reactions. The authors also discuss the stability of sodium salts in solvents and the stability of the battery with the addition of an ionic liquid. The document concludes with a discussion on the deposition of lithium superoxide and its dissolution into the electrolyte solution. The text discusses the experimental observations and calculations related to the growth and stabilization of LiO2 discharge products in lithium-oxygen batteries. The authors note that the epitaxial interfacial energy provides sufficient stabilization energy for LiO2 growth. The text also mentions the solubility of LiO2 in electrolytes and addresses questions about strain, template stabilization, and the conductivity of LiIr3 alloy. Experimental evidence for LiO2 and its disproportionation is mentioned, as well as the potential for using single crystal approaches to test these ideas. The text discusses various aspects of lithium-oxygen (Li-O2) and potassium-oxygen (K-O2) battery systems. It mentions the use of Ir nanoparticles to stabilize LiO2 as a discharge product and the lattice [Extracted from the article]