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The oxygen stacking of O3-type layered sodium transition metal oxides (O3-NaTMO2) changes dynamically upon topotactic Na extraction and reinsertion. While the phase transition from octahedral to prismatic Na coordination that occurs at intermediate desodiation by transition metal slab gliding is well understood, the structural evolution at high desodiation, crucial to achieve high reversible capacity, remains mostly uncharted. In this work, the phase transitions of O3-type layered NaTMO2 at high voltage are investigated by combining experimental and computational approaches. An OP2-type phase that consists of alternating octahedral and prismatic Na layers is directly observed by in situ X-ray diffraction and high-resolution scanning transmission electron microscopy. The origin of this peculiar phase is explained by atomic interactions involving Jahn–Teller active Fe4+ and distortion tolerant Ti4+ that stabilize the local Na environment. The path-dependent desodiation and resodiation pathways are also rationalized in this material through the different kinetics of the prismatic and octahedral layers, presenting a comprehensive picture about the structural stability of the layered materials upon Na intercalation.

Over the last decade, Na-ion batteries have been extensively studied as low-cost alternatives to Li-ion batteries for large-scale grid storage applications; however, the development of high-energy positive electrodes remains a major challenge. Materials with a polyanionic framework, such as Na superionic conductor (NASICON)-structured cathodes with formula NaxM2(PO4)3, have attracted considerable attention because of their stable 3D crystal structure and high operating potential. Herein, a novel NASICON-type compound, Na4MnCr(PO4)3, is reported as a promising cathode material for Na-ion batteries that deliver a high specific capacity of 130 mAh g−1 during discharge utilizing high-voltage Mn2+/3+ (3.5 V), Mn3+/4+ (4.0 V), and Cr3+/4+ (4.35 V) transition metal redox. In addition, Na4MnCr(PO4)3 exhibits a high rate capability (97 mAh g−1 at 5 C) and excellent all-temperature performance. In situ X-ray diffraction and synchrotron X-ray diffraction analyses reveal reversible structural evolution for both charge and discharge.

K-ion batteries are promising alternative energy storage systems for large-scale applications because of the globally abundant K reserves. K-ion batteries benefit from the lower standard redox potential of K/K+ than that of Na/Na+ and even Li/Li+, which can translate into a higher working voltage. Stable KC8 can also be formed via K intercalation into a graphite anode, which contrasts with the thermodynamically unfavorable Na intercalation into graphite, making graphite a readily available anode for K-ion battery technology. However, to construct practical rocking-chair K-ion batteries, an appropriate cathode material that can accommodate reversible K release and storage is still needed. We show that stoichiometric KCrO2 with a layered O3-type structure can function as a cathode for K-ion batteries and demonstrate a practical rocking-chair K-ion battery. In situ X-ray diffraction and electrochemical titration demonstrate that KxCrO2 is stable for a wide K content, allowing for topotactic K extraction and reinsertion. We further explain why stoichiometric KCrO2 is unique in forming the layered structure unlike other stoichiometric K-transition metal oxide compounds, which form nonlayered structures; this fundamental understanding provides insight for the future design of other layered cathodes for K-ion batteries.

The exploration of high-energy-density cathode materials is vital to the practical use of K-ion batteries. Layered K-metal oxides have too high a voltage slope due to their large K+–K+ interaction, resulting in low specific capacity and average voltage. In contrast, the 3D arrangement of K+, with polyanions separating them, reduces the strength of the effective K+-K+ repulsion, which in turn increases specific capacity and voltage. Here, stoichiometric KVPO4F for use as a high-energy-density K-ion cathode is developed. The KVPO4F cathode delivers a reversible capacity of ≈105 mAh g−1 with an average voltage of ≈4.3 V (vs K/K+), resulting in a gravimetric energy density of ≈450 Wh kg−1. During electrochemical cycling, the KxVPO4F cathode goes through various intermediate phases at x = 0.75, 0.625, and 0.5 upon K extraction and reinsertion, as determined by ex situ X-ray diffraction characterization and ab initio calculations. This work further explains the role of oxygen substitution in KVPO4+xF1−x: the oxygenation of KVPO4F leads to an anion-disordered structure which prevents the formation of K+/vacancy orderings without electrochemical plateaus and hence to a smoother voltage profile.

The development of rechargeable batteries using K ions as charge carriers has recently attracted considerable attention in the search for cost-effective and large-scale energy storage systems. In light of this trend, various materials for positive and negative electrodes are proposed and evaluated for application in K-ion batteries. Here, a comprehensive review of ongoing materials research on nonaqueous K-ion batteries is offered. Information on the status of new materials discovery and insights to help understand the K-storage mechanisms are provided. In addition, strategies to enhance the electrochemical properties of K-ion batteries and computational approaches to better understand their thermodynamic properties are included. Finally, K-ion batteries are compared to competing Li and Na systems and pragmatic opportunities and future research directions are discussed.

Triplite-type LiFeSO4F has attracted considerable attention as a promising cathode for next-generation lithium-ion batteries because of its high redox potential based on earth-abundant Fe2+/3+. However, successful extraction/reinsertion of all the lithium ions in triplite host is challenging even at a low current rate, resulting in a low specific capacity. These experimental findings contrast with previous theoretical works that predicted that the triplite structure would be a fast ionic conductor with low activation barriers for lithium-ion hopping. Origin of this discrepancy is elusive to date. Herein, combined first-principles calculations and high-angle annular dark-field scanning transmission electron microscopy analyses reveal that typical triplite structure is composed of nanodomains consisting of corner-shared FeO4F2 octahedra, whereas their domain boundaries are regions of mixed corner/edge-shared FeO4F2 octahedra. More importantly, these locally disordered domain boundaries significantly reduce the overall lithium diffusivity of the materials. Inspired by these findings, this study redesigns triplite structure with sufficiently small sizes to avoid local bottlenecks arising from the domain boundaries, successfully achieving nearly full lithium extraction/reinsertion with high power and energy density. This work represents the first direct observation of the presence of domain boundaries within a crystalline structure playing a critical role in governing the lithium diffusivity in a battery electrode.

The electrochemical properties of NaNi0.5Co0.5O2 and NaNi0.5Fe0.5O2 and their structural transitions as a function of Na extraction associated with redox reactions are investigated in this work. Synthesized in the O3-type layered structure, both materials show reasonable electrochemical activities at room temperature, delivering approximately 0.5 Na per formula unit at C/10 discharge. More Na can be reversibly cycled in NaNi0.5Co0.5O2 at elevated temperature and/or in an extended voltage window, while NaNi0.5Fe0.5O2 shows significant capacity fading at a high voltage cutoff which is likely due to Fe4+ migration. In situ X-ray diffraction shows that the structural changes in the two materials upon desodiation are very different. NaNi0.5Co0.5O2 goes through many different two-phase reactions including three different O3-type and three different P3-type structures during cycling, producing a voltage profile with multiple plateau-like features. In contrast, NaNi0.5Fe0.5O2 has a smooth voltage profile and shows the typical O3-P3 phase transition without lattice distortion seen in other materials. This different structural evolution upon desodiation and re-sodiation can be explained by the electronic structure of the mixed transition metals and how it perturbs the ordering between Na ions differently.

Recent successes with disordered Li-excess materials and applications of percolation theory have highlighted cation-disordered oxides as high capacity and energy density cathode materials. In this work, we present a new class of high capacity cation-disordered oxides, lithium-excess nickel titanium molybdenum oxides, which deliver capacities up to 250 mA h g-1. These materials were designed from percolation theory which predicts lithium diffusion to become facile in cation-disordered oxides as the lithium-excess level increases (x > 1.09 in LixTM2-xO2). The reversible capacity and rate capability in these compounds are shown to considerably improve with lithium excess. In particular, Li1.2Ni1/3Ti1/3Mo2/15O2 delivers up to 250 mA h g-1 and 750 W h kg-1 (∼3080 W h l-1) at 10 mA g-1. Combining in situ X-ray diffraction, X-ray absorption near edge spectroscopy, electron energy loss spectroscopy, and electrochemistry, we propose that first charging Li1.2Ni1/3Ti1/3Mo2/15O2 to 4.8 V occurs with Ni2+/Ni∼3+ oxidation, oxygen loss, and oxygen oxidation in this sequence, after which Mo6+ and Ti4+ can be reduced upon discharge. Furthermore, we discuss how oxygen loss with lattice densification can affect lithium diffusion in the material by decreasing the Li-excess level. From this understanding, strategies for further improvements are proposed, setting new guidelines for the design of high performance cation-disordered oxides for rechargeable lithium batteries.

Kiyoung Lee,1,2 Ie Byung Park,1,2 Seung Hee Yu,2 Soo-Kyung Kim,3 So Hun Kim,4 Da Hea Seo,4 Seongbin Hong,4 Ja Young Jeon,5 Dae Jung Kim,5 Soo Wan Kim,6 Cheol Soo Choi,1,2 Dae Ho Lee1,21Department of Internal Medicine, Gachon University College of Medicine, Incheon, Republic of Korea; 2Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea; 3Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea; 4Department of Internal Medicine, Inha University School of Medicine, Incheon, Republic of Korea; 5Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Republic of Korea; 6Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of KoreaAim: We aimed to evaluate the clinical utility of blood ketone measurement and to test the performance of the diagnostic criteria for diabetic ketoacidosis (DKA) issued by the American Diabetes Association, the Joint British Diabetes Societies, and the American Association of Clinical Endocrinologists and the American College of Endocrinology.Methods: This retrospective analysis included 278 patients with suspected DKA who were hospitalized at 4 university hospitals and aged ≥16 years with a blood glucose level of >200 mg/dL and a blood ketone level of ≥1.0 mmol/L as well as other biochemical data. The patients were categorized into four subgroups (ketosis, typical DKA, atypical DKA, and DKA + lactic acidosis). Atypical DKA in each analysis was defined by our supplementary criteria if the biochemical data did not meet each set of diagnostic criteria from the aforementioned societies.Results: Blood ketone levels in patients with diabetic ketosis and those with DKA varied widely, 1.05–5.13 mmol/L and 1.02–15.9 mmol/L, respectively. Additionally, there were significant discrepancies between the guidelines in the diagnosis of DKA. Thus, the proportion of patients with atypical DKA ranged from 16.5% to 42.4%. Notably, the in-hospital mortality was comparable between patients with typical and atypical DKA, with a very high mortality in patients with DKA + lactic acidosis (blood lactate >5 mmol/L).Conclusions: Our results showed that considering variable presentations of DKA, blood ketone data need to be interpreted cautiously along with other biochemical data and suggested that a new system is required to better characterize DKA.Keywords: Diabetic ketoacidosis, ketone bodies, diagnosis, lactic acidosis, acid base imbalance

Seung Rim Hwang,1 Dong-Hyun Seo,2 Youngro Byun,3 Jin Woo Park4 1Department of Pharmacy, College of Pharmacy, Chosun University, Gwangju, 2Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, Gangwon, 3Department of Molecular Medicine and Biopharmaceutical Science, Graduate School of Convergence Science and Technology, College of Pharmacy, Seoul National University, Seoul, 4Department of Pharmacy, College of Pharmacy and Natural Medicine Research Institute, Mokpo National University, Muan-gun, Jeonnam, Republic of Korea Abstract: The N-terminal 34-amino-acid peptide fragment of human parathyroid hormone PTH (1-34), is used clinically to treat osteoporosis; however, it is currently administered by a once-daily subcutaneous injection, resulting in poor patient compliance. We have developed enteric microcapsules containing an ionic nanocomplex between PTH (1-34) and lysine-linked deoxycholic acid (LysDOCA) for the oral delivery of PTH (1-34). We measured the particle size of the PTH/LysDOCA complex and assessed its biological activity by determining the cAMP content in MC3T3-E1 cells. We also assessed its permeability across a Caco-2 cell monolayer and the bioavailability of the intrajejunally administered PTH/LysDOCA complex compared with PTH (1-34) in rats. In addition, the antiosteoporotic activity of the PTH/LysDOCA complex, encapsulated in an enteric carrier by coaxial ultrasonic atomization, was evaluated after it was orally administered to ovariectomized (OVX) rats. The formation of an ionic complex between PTH (1-34) and LysDOCA produced nanoparticles of diameter 33.0±3.36 nm, and the bioactivity of the complex was comparable with that of PTH (1-34). The Caco-2 cell permeability and AUClast value of the PTH/LysDOCA (1:10) nanocomplex increased by 2.87- and 16.3-fold, respectively, compared with PTH (1-34) alone. Furthermore, the OVX rats treated with oral PTH/LysDOCA-loaded enteric microcapsules showed an increase in bone mineral density (159%), bone volume fraction (175%), and trabecular number (174%) compared with those in the OVX control group. Therefore, the PTH/LysDOCA nanocomplex oral delivery system is a promising treatment modality for osteoporosis because it improves osteogenesis and trabecular connectivity. Keywords: oral delivery, parathyroid hormone, nanocomplex, deoxycholic acid, coaxial ultrasonic atomization, osteoporosis

The study aimed to develop an efficient bioprocess for the discovery and synthesis of theanderose by using amylosucrase from Deinococcus deserti ( Dd AS). An unknown trisaccharide produced by Dd AS was detected by high-performance anion-exchange chromatography-pulsed amperometric detection and high-performance liquid chromatography-evaporative light scattering detection, purified using medium-pressure liquid chromatography, and identified as theanderose (α-d-glucopyranosyl-(1→6)-α-d-glucopyranosyl-(1→2)-β-d-fructofuranoside) through nuclear magnetic resonance and mass spectrometry. Dd AS synthesized theanderose with a 25.4% yield (174.1 g/L) using 2.0 M sucrose at 40 °C for 96 h. In an in vitro digestion model, theanderose showed a 6.5% hydrolysis rate over 16 h. Prebiotic efficacy tests confirmed that theanderose significantly enhanced the proliferation of selected Bifidobacterium strains in the culturing medium with theanderose as the main carbon source. Subsequently, fecal fermentation was performed by adding theanderose to the feces of 20 individuals of varying ages to assess its effect on the gut microbiota. Theanderose increased the relative abundance of Bifidobacteriaceae and Prevotellaceae while decreasing the population ratio of Lachnospiraceae and Ruminococcaceae . Conclusively, theanderose displayed excellent prebiotic potential when judged by low digestibility and selective growth of beneficial microbes over harmful microbes.

Characterizing the spatial distribution of the electromagnetic fields of a plasmonic nanoparticle is crucial for exploiting its strong light-matter interaction for optoelectronic and catalytic applications. However, observing the near-fields in three dimensions with a high spatial resolution is still challenging. To realize efficient three-dimensional (3D) nanoscale mapping of the plasmonic fields of nanoparticles with complex shapes, this work established autoencoder-embedded electron energy loss spectroscopy (EELS) tomography. A 432-symmetric chiral gold nanoparticle, a nanoparticle with a high optical dissymmetry factor, was analyzed to relate its geometrical features to its exotic optical properties. Our deep-learning-based feature extraction method discriminated plasmons with different energies in the EEL spectra of the nanoparticle in which signals from multiple plasmons were intermixed; this component was key for acceptable 3D visualization of each plasmonic field separately using EELS tomography. With this methodology, the electric field of the plasmon that induces far-field circular dichroism was observed in 3D. The field linked to this chiroptical property was strong along the swirling edges of the particle, as predicted by a numerical calculation. This study provides insight into the correlation between structural and optical chiralities through direct 3D observation of the plasmonic fields. Furthermore, the strategy of implementing an autoencoder for EELS tomography can be generalized to achieve competent 3D analysis of other features, including the optical properties of the dielectrics and chemical states.

All-solid-state batteries (ASSBs) possess the advantage of ensuring safety while simultaneously maximizing energy density, making them suitable for next-generation battery models. In particular, sulfide solid electrolytes (SSEs) are viewed as promising candidates for ASSB electrolytes due to their excellent ionic conductivity. However, a limitation exists in the form of interfacial side reactions occurring between the SSEs and cathode active materials (CAMs), as well as the generation of sulfide-based gases within the SSE. These issues lead to a reduction in the capacity of CAMs and an increase in internal resistance within the cell. To address these challenges, cathode composite materials incorporating zinc oxide (ZnO) are fabricated, effectively reducing various side reactions occurring in CAMs. Acting as a semiconductor, ZnO helps mitigate the rapid oxidation of the solid electrolyte facilitated by an electronic pathway, thereby minimizing side reactions, while maintaining electron pathways to the active material. Additionally, it absorbs sulfide-based gases, thus protecting the lithium ions within CAMs. In this study, the mass spectrometer is employed to observe gas generation phenomena within the ASSB cell. Furthermore, a clear elucidation of the side reactions occurring at the cathode and the causes of capacity reduction in ASSB are provided through density functional theory calculations., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

Turanose (α-d-glucopyranosyl-(1→3)-α-d-fructose) is a rare disaccharide that is a potential low-calorigenic sweetener. This novel sucrose isomer has been efficiently synthesized by the amylosucrase from Bifidobacterium thermophilum (BtAS). In this study, we aimed to enhance turanose biosynthesis by designing a BtAS variant (BtAS-G374S) with improved thermal stability. The BtAS variant was immobilized on porosity-controlled silica carrier, and its enzymatic properties were thoroughly investigated. Using response surface methodology with central composite design, optimal immobilization conditions were determined to significantly boost the biosynthetic efficiency. The BtAS-G374S showed 1.6-fold higher specific activity (2.2 U/mg) than the wild-type enzyme (1.4 U/mg). Additionally, the turanose production yield of BtAS-G374S was significantly enhanced, reaching 65 %, compared to 25 % for the wild-type enzyme when reacting with 2 M sucrose. Immobilization of BtAS-G374S was optimized on controlled porosity carrier (CPC) silica carrier using Response Surface Methodology, achieving an enzyme activity of 7.89 U and an immobilization efficiency of 68.98 % under optimal conditions. Immobilization of BtAS-G374S on CPC silica carriers enhanced its pH and thermal stability. The immobilized enzyme showed a half-life of 50.23 h at 55 °C and retained 68 % of its initial biosynthetic yield after 10 reuses. These properties suggest its potential for efficient industrial turanose production., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier B.V.)

The lithium-mediated nitrogen reduction reaction (Li-NRR) is a promising green alternative to the Haber-Bosch process for ammonia synthesis. The solid electrolyte interphase (SEI) is crucial for high efficiency and stability, as it regulates reactant diffusion and suppresses side reactions. The SEI properties are greatly influenced by the Li + ion solvation structure, which is controllable through electrolyte engineering. Although anion-derived SEI enhances selectivity and stability, it has typically been engineered using high-concentration electrolytes (HCEs), which face mass transfer, viscosity, and cost issues. In this study, a localized high-concentration electrolyte (LHCE) in the Li-NRR is first introduced, enabling the formation of anion-derived SEI in a low-concentration electrolyte (LCE) by enhancing the Li-anion coordination using an antisolvent. Among various antisolvents, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) achieves the highest ammonia Faradaic efficiency (73.6 ± 2.5%), more than double that of the LCE (34.3 ± 2.8%) and exceeding the HCE (56.0 ± 2.8%). Systematic calculations and experimental analyses show that the LHCE exhibits anion-rich solvation structures and forms thin, inorganic SEI. Moreover, the LHCE has advantages of low viscosity and high N 2 solubility, which facilitate mass transport. This study suggests the application of LHCE as an effective electrolyte engineering strategy to enhance the Li-NRR efficiency., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Kinetic energy harvesting has significant potential, but current methods, such as friction and deformation-based systems, require high-frequency inputs and highly durable materials. We report an electrochemical system using a two-phase immiscible liquid electrolyte and Prussian blue analogue electrodes for harvesting low-frequency kinetic energy. This system converts translational kinetic energy from the displacement of electrodes between electrolyte phases into electrical energy, achieving a peak power of 6.4 ± 0.08 μW cm -2 , with a peak voltage of 96 mV and peak current density of 183 μA cm -2 using a 300 Ω load. This load is several thousand times smaller than those typically employed in conventional methods. The charge density reaches 2.73 mC cm -2 , while the energy density is 116 μJ cm -2 during a harvesting cycle. Also, the system provides a continuous current flow of approximately 5 μA cm -2 at 0.005 Hz for 23 cycles without performance decay. The driving force behind voltage generation is the difference in solvation Gibbs free energy between the two electrolyte phases. Additionally, we demonstrate the system's functionality in a microfluidic harvester, generating a maximum power density of 200 nW cm -2 by converting the kinetic energy to propel the electrolyte through the microfluidic channel into electricity., (© 2024. The Author(s).)