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The electrochemical properties and performances of lithium-ion batteries are primarily governed by their constituent electrode materials, whose intrinsic thermodynamic and kinetic properties are understood as the determining factor. As a part of complementing the intrinsic material properties, the strategy of nanosizing has been widely applied to electrodes to improve battery performance. It has been revealed that this not only improves the kinetics of the electrode materials but is also capable of regulating their thermodynamic properties, taking advantage of nanoscale phenomena regarding the changes in redox potential, solid-state solubility of the intercalation compounds, and reaction paths. In addition, the nanosizing of materials has recently enabled the discovery of new energy storage mechanisms, through which unexplored classes of electrodes could be introduced. Herein, we review the nanoscale phenomena discovered or exploited in lithium-ion battery chemistry thus far and discuss their potential implications, providing opportunities to further unveil uncharted electrode materials and chemistries. Finally, we discuss the limitations of the nanoscale phenomena presently employed in battery applications and suggest strategies to overcome these limitations.

A highly soluble and multi-redox phenazine-based molecule, BMEPZ, is redesigned through bio-inspiratioin as high-performance catholyte material for NORFBs. A full-flow RFB based on BMEPZ/FL redox couple exhibits cell voltage of 1.2 and 2.0 V and stable cycling. The highest energy density among NORFBs is attained based on the multi-redox capability and high solubility.

A spatial confinement effect of copper nanoparticles in an ordered mesoporous γ-Al2O3, which is synthesized by an evaporation induced self-assembly (EISA) method, was investigated to verify the enhanced catalytic activity and stability with less aggregation of copper crystallites during direct synthesis of dimethyl ether (DME) from syngas. The surface acidity of the mesoporous Al2O3 and the metallic copper surface area significantly altered catalytic activity and stability. The ordered mesopore structures of Al2O3 were effective to suppress the aggregation of copper nanoparticles even under reductive CO hydrogenation conditions through the spatial confinement effect of the ordered mesopores of Al2O3 as well as the formation of strongly interacted copper nanoparticles with the mesoporous Al2O3 surfaces by partial formation of the interfacial CuAl2O4 species. The aggregation of copper nanoparticles on the bifunctional Cu/meso-Al2O3 having an ordered mesoporous structure was effectively suppressed due to the partial formation of the thermally stable spinel copper aluminate phases, which can further generate new acid sites for dehydration of methanol intermediate to DME.

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The use of lithium metal either in an anode or anode-free configuration is envisaged as the most promising way to boost the energy density of the current lithium-ion battery system. Nevertheless, the uncontrolled lithium dendritic growth inhibits practical utilization of lithium metal as an anode due to safety concerns and low Coulombic efficiency. In this work, we show that when a high-dielectric SEI is coated on a current collector, it can effectively promote a uniform lithium deposition by decreasing the overpotential between the surfaces, lowering the local current density and suppressing lithium protrusions. Using a PVDF (polyvinylidene difluoride)-based dielectric medium, it is demonstrated that varying the dielectric properties of PVDF by crystallinity control can regulate the lithium deposition mechanisms. Moreover, when the dielectric properties of PVDF film are tailored by the inclusion of dielectric nanoparticles, a selective formation of high-dielectric β-PVDF phase is induced during its film formation (LiF@PVDF), which synergistically promotes uniform lithium deposition/stripping in an anode-free half-cell setup.

To meet the ever-increasing energy demands and sustainability requirements, next-generation battery systems must provide superior energy densities while employing eco-friendly components. Transition metal oxide-based materials have served as important high-energy-density battery electrodes over the past few decades; however, their further development is challenging as we approach the theoretical limits arising from their crystal structures and constituting elements. Exploiting materials from biological systems, or bio-inspiration, offers an alternative strategy to overcome the conventional energy storage mechanism through the chemical diversity, highly efficient biochemistry, sustainability, and natural abundance provided by these materials. Here, we overview recent progress in biomimetic research focused on novel electrode material design for rechargeable batteries, exploiting redox-active molecules involved in the biometabolism and diverse bioderived materials with various morphologies. Successful demonstrations of energy storage using biomimetic materials that simultaneously exhibit outstanding performance and sustainability would provide insight toward the development of an eco-friendly and highefficiency energy storage system.

Phylogenomic tree reconstruction has recently become a routine and critical task to elucidate the evolutionary relationships among bacterial species. The most widely used method utilizes the concatenated core genes, universally present in a single-copy throughout the bacterial domain. In our previous study, a bioinformatics pipeline termed Up-to-date Bacterial Core Genes (UBCG) was developed with a set of bacterial core genes selected from 1,429 species covering 28 phyla. In this study, we revised a new bacterial core gene set, named UBCG2, that was selected from the more extensive genome sequence set belonging to 3,508 species spanning 43 phyla. UBCG2 comprises 81 genes with nine Clusters of Orthologous Groups of proteins (COGs) functional categories. The new gene set and complete pipeline are available at http://leb.snu.ac.kr/ubcg2.