From Fundamental Understanding to Engineering Design of High‐Performance Thick Electrodes for Scalable Energy‐Storage Systems

Abstract The ever‐growing needs for renewable energy demand the pursuit of batteries with higher energy/power output. A thick electrode design is considered as a promising solution for high‐energy batteries due to the minimized inactive material ratio at the device level. Most of the current research focuses on pushing the electrode thickness to a maximum limit; however, very few of them thoroughly analyze the effect of electrode thickness on cell‐level energy densities as well as the balance between energy and power density. Here, a realistic assessment of the combined effect of electrode thickness with other key design parameters is provided, such as active material fraction and electrode porosity, which affect the cell‐level energy/power densities of lithium–LiNi 0.6 Mn 0.2 Co 0.2 O 2 (Li–NMC622) and lithium–sulfur (Li–S) cells as two model battery systems, is provided. Based on the state‐of‐the‐art lithium batteries, key research targets are quantified to achieve 500 Wh kg –1 /800 Wh L –1 cell‐level energy densities and strategies are elaborated to simultaneously enhance energy/power output. Furthermore, the remaining challenges are highlighted toward realizing scalable high‐energy/power energy‐storage systems.