With the increasing global demand for sustainable energy and the pressing challenges posed by fossil fuel dependence, the development of efficient and environmentally friendly energy storage systems has become a critical priority. This thesis explores novel organic and metal-organic cathode materials constructed from hexa-anionic building blocks, designed to overcome solubility limitations and enhance key energy metrics. By addressing fundamental material bottlenecks, it advances high-performance, practical battery chemistries and demonstrates rare mixed proton-electron conductivity in three-dimensional metal-organic frameworks. This work paves the way for a rich landscape of materials with tunable electrochemical and structural properties, offering new opportunities for the design of next-generation energy storage technologies.