The use of key parameters of the SiO$_x$/graphite electrode formulation, and their critical values, makes it possible, without any trial-and-error type experimentation, to identify optimal electrode formulations for different SiO$_x$/graphite mass ratios ranging up to 40:60. From the first attempt, electrodes presenting good cyclability at high surface capacity of 5.2 mA h cm$^{−2}$ were formulated, reaching for example more than 93% capacity retention after 60 cycles in a full cell, with an electrolyte rich in FEC and EC-free, however with a prelithiation strategy. With a positive electrode based on NMC 811 , the gains in volumetric energy and power density are + 18 and + 28% compared to graphite, considering only the electrode volumes. The principle of using the key electrode formulation parameters introduced here is expected to accelerate and facilitate the optimization of electrode formulations.