Multiscale Design Concepts for High‐Areal‐Capacity Cathodes Toward Practical Lithium Batteries

A promising strategy for achieving high-energy-density involves implementing high-areal-capacity cathodes, which minimize the proportion of inactive components within the battery. However, high-areal-capacity cathodes are fundamentally hindered by multiscale limitations, including microscopic issues associated with the chemo-mechanical properties of conventional binders and macroscopic constraints arising from increased tortuosity in thick electrodes. This review article explores two representative approaches to realizing high-areal-capacity cathodes. The review begins with a quantitative analysis illustrating how an increase in electrode thickness results in improved energy density. The subsequent section outlines the analytical methodologies used to diagnose the key limitations of high-areal-capacity electrodes and to verify the effectiveness of strategies developed to overcome these challenges. Building on these analytical insights, the following section discusses the critical properties required of polymer binders to address these technical issues, followed by practical examples that demonstrate successful binder designs. The review then introduces electrode architectural engineering strategies, highlighting how continuous and durable pathways can be constructed within electrodes to enhance both ionic/electronic conductivity, as well as overall structural integrity. Overall, this discussion provides a comprehensive design perspective that bridges material-level and structural-level considerations, offering general guidelines for the development of practical high-energy-density batteries enabled by high-areal-capacity electrode technology.