In a battery system, electrodes containing porous graphene scaffolding offer a substantial improvement in both the retention and transport of energy, a new study reveals. Usually, techniques to improve the density of stored charge conflict with those that aim to improve the speed at which ions can move through a material. Nanostructured materials have shown extraordinary promise for electrochemical energy storage, but these materials are usually limited to laboratory cells with ultrathin electrodes and very low mass loadings. Hongtao Sun et al. overcome this obstacle by incorporating holey graphene into a niobium pentoxide electrode. The nanopores facilitate rapid ion transport. By "fine-tuning" the size of the nanopores, the researchers were able to achieve high mass loading and improved power capability, while still maintaining the higher charge transport. In a related Perspective, Hui-Ming Cheng and Feng Li write, "An unprecedented combination of high areal capacity and current density at practical mass loadings (10 to 20 mg cm-2) marks a critical step toward the use of high-performance electrode materials in commercial cells."
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Science