Unlocking Zero‐Carbon Buildings via Solid‐State Energy Storage Wallboards Enabled by Superionic Oriented Layered Magnesia‐Cement Electrolytes

ABSTRACT Cement occupies a significant proportion in construction, serving as the primary material for components such as bricks and walls. However, its role is largely limited to load‐bearing functions, with little exploration of additional applications. Simultaneously, buildings remain a major contributor to global energy consumption, accounting for 40% of total energy use. Here, we for the first time endow cement with energy storage functionality by developing cement‐based solid‐state energy storage wallboards (CSESWs), which can utilize the ample idle surface areas of building walls to seamlessly store renewable energy from distributed photovoltaics without compromising building safety or requiring additional space. Owing to unprecedented microstructures and composition interactions, these CSESWs not only achieve a superionic conductivity of 101.1 mS cm −1 but also demonstrate multifunctionality, such as significant toughness, thermal insulation, lightweight, and adhesion. When integrated with asymmetrical electrodes, the CSESWs exhibit a remarkable capacitance (2778.9 mF cm −2 ) and high areal energy density (10.8 mWh cm −2 ). Moreover, existing residential buildings renovated with our CSESWs can supply 98% of daily electricity needs, demonstrating their outstanding potential for realizing zero‐carbon buildings. This study pioneers the use of cement in energy storage, providing a scalable and cost‐effective pathway for sustainable construction.