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Silicon is widely recognized as the most promising upgrade for graphite anodes due to its much higher capacity, natural abundance, and ability to be directly applied in the slurry-based, roll-to-roll production lines. However, in addition to the fast capacity decay, silicon anodes also suffer from inferior calendar life in practical applications due to the unstable solid-electrode interface (SEI). Until now, strategies to effectively improve the calendar life by tailored SEIs remain largely unclear, especially in high-Si content, zero-graphite anodes. Here, silicon anodes with superior calendar life are developed by adding small concentrations of multivalent salts into the baseline electrolyte. The Ca additive reacts with the F ions in the electrolyte, forming a layer of nanocrystalline CaF2 that is closely coated around the silicon particles. The CaF2-enabled new SEI is strong and dense, which effectively protects the silicon core from side reactions, leading to lower capacity decay after calendar aging at high voltage. More importantly, the Ca additive is effective universally for all available commercial silicon or SiO sources. This study provides a feasible and low-cost solution for developing silicon anodes with long calendar life, paving the way towards commercially viable silicon anodes.

The protonic ceramic electrochemical cell (PCEC) is an emerging and attractive technology that converts energy between power and hydrogen using solid oxide proton conductors at intermediate temperatures. To achieve efficient electrochemical hydrogen and power production with stable operation, highly robust and durable electrodes are urgently desired to facilitate water oxidation and oxygen reduction reactions, which are the critical steps for both electrolysis and fuel cell operation, especially at reduced temperatures. In this study, a triple conducting oxide of PrNi0.5Co0.5O3-δ perovskite is developed as an oxygen electrode, presenting superior electrochemical performance at 400~600 °C. More importantly, the self-sustainable and reversible operation is successfully demonstrated by converting the generated hydrogen in electrolysis mode to electricity without any hydrogen addition. The excellent electrocatalytic activity is attributed to the considerable proton conduction, as confirmed by hydrogen permeation experiment, remarkable hydration behavior and computations.

Flexible crystalline solids exhibit unique properties in response to external stimuli like heat and light. However, challenges exist in developing crystalline solids that have similar degrees of flexibility as in solution. Herein, we report the preparation of the new flexible crystalline metal complex [Cd(CF3SO3)2(4‐spy)4] (4‐spy=4‐styrylpyridine), which contains photoreactive 4‐spy ligand. Unlike traditional solids, this metal complex displays solution state‐like [2+2] photocycloaddition reactivity. Specifically, UV irradiation of the crystalline material leads to formation of the same diverse array of dimers and cis isomer that are generated by photoreaction in the solution state. In addition, the photoresponsive flexibility of the solid leads to a photosalient effect and photo‐induced formation of pores. The origin of the solution state‐like photoreactivity of the solid is related to properties of the Cd(II) cation and fluorinated CF3SO3 anion, and the multi‐orientational arrangement of the 4‐spy ligands. [ABSTRACT FROM AUTHOR]

The article discusses various research articles published in the journal Angewandte Chemie International Edition. One article explores the challenges of developing flexible crystalline solids that mimic the flexibility of solutions. Another article focuses on the importance of phosphorescence lifetime in enhancing the imaging quality of phosphorescence materials for bioimaging. Additionally, the article mentions research on self-assembled chiral polymers with amplified circularly polarized electroluminescence, a method for screening organic/ferromagnetic interfaces using X-ray spectroscopies, and a strategy for fabricating high-quality hydrogen-bonded organic framework membranes for gas separation. [Extracted from the article]

The article discusses various research findings in the field of chemistry. One study focuses on the development of flexible crystalline solids that exhibit similar flexibility to solutions. Another study explores the importance of phosphorescence lifetime in enhancing the imaging quality of phosphorescence materials for bioimaging. Additionally, the article mentions research on self-assembled chiral polymers with amplified circularly polarized electroluminescence, a method for screening organic/ferromagnetic interfaces using X-ray spectroscopies, and a strategy for fabricating high-quality gas separation membranes. [Extracted from the article]