Operando interlayer expansion of curved graphene for dense supercapacitors (www.nature.com)

Researchers have developed a new type of multiscale graphene structure aimed at enhancing the performance of supercapacitors, addressing limitations in volumetric energy density. By utilizing a two-step rapid thermal annealing process, they created curved turbostratic graphene crystallites interwoven with disordered domains in micron-scale particles. This innovative design facilitates rapid ion transport and improves the matching of pore sizes to electrolyte ions, enabling a remarkable surface-area-normalized capacitance of up to 85 µF/cm² in organic electrolytes and 135 µF/cm² in ionic liquids. The significance of this advancement lies in its potential to revolutionize energy storage technologies, crucial for the growth of compact, high-performance electronic devices. The resulting pouch cells demonstrated impressive volumetric energy densities of 99.5 Wh/L with ionic liquids and 49.2 Wh/L in organic electrolytes, accompanied by high power densities of up to 69.2 kW/L. This breakthrough not only highlights the role of multiscale design in optimizing supercapacitor performance but also poses important questions about the limitations of conventional graphite structures, promoting further investigation into optimizing graphene's unique properties for enhanced energy storage applications.