The commercialization of high energy density systems has the potential to radically improve cost ($/kWh) and adoption in both the automotive and grid energy spaces. A hybrid cell concept in which separate electrolytes are used with the cathode and anode of a single cell allows the cathode electrolyte (catholyte) to be selected for oxidative stability with a high voltage cathode, and the anode electrolyte (anolyte) to be selected for reductive stability with a high capacity anode (e.g., silicon-carbon or Li metal). The combination enables cells of exceptional energy density while retaining stability and life heretofore only available at much lower cell voltages. This approach is ideally suited for use with semi-solid electrodes of 24M’s proprietary design, made by an innovative manufacturing process in which the electrolyte also serves the function of a processing solvent, being directly mixed with active materials and conductive additives prior to forming. Electrode drying, calendaring, and the use of binder are eliminated. Since the semi-solid cathode and anode are independently processed, a different electrolyte composition can be selected for each. 24M’s “unit cell” architecture, in which thick electrodes and high areal capacities are used to create high energy density cell products with reduced inactive materials content has the potential to revolutionize next-generation battery performance.