Electrochemical Thermodynamics, Kinetics, and Hysteresis in Ener-gy Materials: Focusing on the Solid Side

Abstract

Bulk electrochemical phase transitions (EPTs) are the cornerstone of most modern electro-chemical technologies, underlying many energy storage and electrocatalytic systems. Nonetheless, the fundamental mechanisms governing EPTs in solid-to-solid systems re-main only partially understood because they involve complex interactions between phase transitions and electrochemical reactions. This mini-review introduces the thermodynam-ics of EPTs based on the general framework of phase transitions and mixtures, followed by a discussion of electrochemical hysteresis and kinetics in EPTs. Finally, using recent insights into the EPTS in Ni(OH)2, LiFePO4, and MnO2 materials, the importance of Cyclic Voltamme-try (CV) modelling in discerning underlying reaction mechanisms is highlighted. This mini-review inspires fundamental research into solid-to-solid EPTs for improving the perfor-mance of current energy storage materials.