Effect of Electrode/Electrolyte Coupling on Birnessite (δ-MnO) Mechanical Response and Degradation.

Understanding the deformation of energy storage electrodes at a local scale and its correlation to electrochemical performance is crucial for designing effective electrode architectures. In this work, the effect of electrolyte cation and electrode morphology on birnessite (δ-MnO) deformation during charge storage in aqueous electrolytes was investigated using a mechanical cyclic voltammetry approach via atomic force microscopy (AFM) and molecular dynamics (MD) simulation. In both KSO and LiSO electrolytes, the δ-MnO host electrode underwent expansion during cation intercalation, but with different potential dependencies.

Understanding the Water-in-Salt to Salt-in-Water Characteristics across the Zinc Chloride : Water Phase Diagram.

Using a series of time- and temperature-resolved synchrotron diffraction experiments, the relationship between multiple polymorphs of ZnCl and its respective hydrates is established. The δ-phase is found to be the pure anhydrous phase, while the α, β, and γ phases result from partial hydration. Diffraction, gravimetric, and calorimetric measurements across the entire ZnCl· HO, 0 > > ∞ composition range using ultrapure, doubly sublimed ZnCl establish the ZnCl : HO phase diagram.