| Abstract Scope |
Batteries are an excellent solution to implement grid-level renewable energy storage. Existing batteries rely on intercalation cathodes that lack large charge capacities needed for grid storage, because of their single-electron redox per metal cation. Conversion cathodes, which undergo multi-electron redox reactions, represent an exciting opportunity to instead use more abundant and environmentally friendly materials at a lower cost. Unfortunately, conversion electrodes exhibit poor reversibility, in large part due to changes in crystal structure and local bonding. These reaction pathways appear to be dependent on cathode composition and crystal structures in relationships that are not well understood. We aim to further our understanding of the mechanism of the structural changes by exploring phase nucleation, transformations, and growth in several case studies of representative materials. We correlate these features to cycling stability and reaction reversibility. With this understanding, we can take the next step towards commercializing these batteries for high energy-density applications. |