The objectives of the project are to understand how reactions are controlled by the evolved electrical conductivity of the conversion electrodes upon phase separation and recombination processes in high-energy-density conversion electrodes.  Conversion materials promised high capacity and high energy density but suffered from poor reversibility due to the complex phase separation and recombination processes. The complexities arise from the formation of several new phases of conversion products, resulting in the formation of heterogeneous solid mixtures. These mixtures of conversion products often form a metal-insulator matrix that reconstructs the original ionic and electrical conduction pathways, and the consequences and effects are not well studied and understood.  Given these complexities, the reversibility between phase separation and recombination processes is difficult of achieve, and the understanding of conversion materials is restrained.   Spatially resolved electrical measurement, elemental composition quantifications, and structural determination will be used as means to reveal the reaction propagation, reaction rates, and reaction dynamics.