A5021169211- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Supercapacitor Materials and Fabrication
- Advanced Battery Technologies Research
- Magnetic and transport properties of perovskites and related materials
- Conducting polymers and applications
- Extraction and Separation Processes
- Thermal Expansion and Ionic Conductivity
- Anodic Oxide Films and Nanostructures
- Environmental Toxicology and Ecotoxicology
- Aerogels and thermal insulation
- Microbial Fuel Cells and Bioremediation
- Microbial Community Ecology and Physiology
- Electrospun Nanofibers in Biomedical Applications
- Interconnection Networks and Systems
- Analytical chemistry methods development
- Nuclear materials and radiation effects
- Layered Double Hydroxides Synthesis and Applications
- Pesticide and Herbicide Environmental Studies
- Anaerobic Digestion and Biogas Production
- Advanced battery technologies research
- Microwave Dielectric Ceramics Synthesis
- Fuel Cells and Related Materials
Tokyo University of Agriculture and Technology
2013-2024
Kanagawa University
2012-2015
Material (Belgium)
2015
Tokyo Institute of Technology
2013
Anisotropically grown Li3V2(PO4)3 nanocrystals, which are highly dispersed and directly impregnated on the surface of a carbon nanofiber (CNF), were successfully synthesized via two-step synthesis process: i) precipitation nanoplated V2O3 precursors (20–200 nm); ii) transformation precursor into nanoplates without size change. The direct attachment nanocrystals to improves electronic conductivity Li+ diffusivity entire Li3V2(PO4)3/CNF composite, simultaneously producing mesoporous network...
Electrochemical capacitors are known for their high power density and cyclability, various redox reactions can be utilized to improve energy density. A great variety of materials have been investigated recently use in electrochemical capacitors, not only transition metal oxides, which studied many years. In this review, we provide a comprehensive explanation capacitors. Manganese oxides ruthenium typical exhibiting pseudocapacitance, first discussed. Nickel used hybrid also covered. Various...
Rechargeable batteries using multivalent metals are among the most promising next-generation battery systems due to their high capacity, safety, and low cost compared with lithium-ion batteries. However, strong cation–anion interaction degrades diffusion in solid cathodes, an effect that must be mitigated yield practical metal We show a highly defective iron phosphate–carbon composite prepared by ultracentrifugation serves as reversible insertion/deinsertion for magnesium ions with, operates...
Mg2+ secondary batteries are remarkably safe, resourceful, and exhibit high energy density. However, the excessively slow reaction kinetics at Mg2+-battery cathode materials results in charge–discharge over 10–60 h room temperature, hindering performance evaluation mechanistic analysis of electrode materials. In this study, we developed a dual-salt electrolyte comprising conventional magnesium salt, bis(trifluoromethanesulfonyl)imide [Mg(TFSA)2], quaternary ammonium...
Factors affecting the cyclability of Fe-substituted LiCoPO4 (LiCo0.8Fe0.2PO4, LCFP) material were elucidated, including both structural and electrode/electrolyte stability. Electrochemical characterization synthesized LCFP nanoparticles lends clear evidence for improved electrochemical stability LCP, as well enhanced rate capability, with Fe3+ substitution. Surface analysis using X-ray photoelectron spectroscopy (XPS) electron energy loss (EELS) suggest that Fe enrichment on surface occurs...
Nanocrystalline γ-Li 3.2 V 0.8 Si 0.2 O 4 /carbon composites with a unique double capsule structure were prepared by spray-drying and annealing processes using an ultra-dilute dispersion as feed solution, exhibiting remarkable performance for lithium-ion storage.
Electrical energy storage (EES) devices are at the core of environmental technologies that highly influential in advancing our life a future society. Among different EES technologies, electric double layer capacitors (EDLCs) considered as promising due to their high-power, safe and long-lived characteristics. One approaches further enhance cell voltage density EDLCs while maintaining high power is replace activated carbon with ultrafast lithium ion battery materials. Increasing contribute...
Full cells consisting of nanocrystalline Li3V2(PO4)3 (LVP) positive and standard commercial Li4Ti5O12 (LTO) negative electrodes demonstrated outstanding cyclability: capacity retention 77% over 10,000 cycles. We achieved this stable cycle performance by electrochemical preconditioning LTO with Li prior to full-cell cycling. The strategy not only allows adjustment the state charge (SOC) between electrodes, but also gives rise formation a protective covering layer on surface. As we show, plays...
The substitution of Ti 4+ into LVP increased the electron density V–O bonds and modified surface morphology, resulting in suppressed vanadium dissolution longer cyclability over 10 000 cycles for cathode-based full cells.
Highly-dispersed 10 wt% FePO4 (FP)-coated LiCo0.90Ti0.05PO4 (LCTP) was successfully synthesized within a multiwalled carbon nanotube matrix via our original ultracentrifugation process. FP-coated LCTP sample showed higher discharge capacity of 116 mA h g-1 together with stable cycle performance over 99% retention at the 100th in high voltage. A combination TEM, XRD, XPS, and XAFS analyses suggests that (i) Ti4+-substitution increases utilization Co redox (capacity increase) LCP crystals by...
Nano-V 2 (PO 4 ) 3 /KB cathodes demonstrated an ultrafast cathode reaction with Mg 2+ insertion/extraction at ambient temperature through a solid-solution reaction.
Highly-dispersed Li3V1.8Al0.2(PO4)3 nanoparticles which are directly impregnated onto the surface of multi-walled carbon nanotubes (MWCNT) were successfully synthesized via a unique two-step process using an ultracentrifugation at 75,000 g. The synthetic procedure Li3V1.8Al0.2(PO4)3/MWCNT composite involves following two steps: i) precipitation V1.8Al0.2O3 (10–100 nm) on MWCNT, and ii) subsequent transformation into without any change their shape dimensions. 10% Al-doping brought out...
LaLnO3 (Ln = Dy, Ho, Y, Er, and Yb) La(Ln, Ln')O3 (Ln, Ln' systems were synthesized by solid state reaction method characterized X-ray diffraction. When Ln Er or Yb which has smaller ionic radius than that of Y3+ (0.900 Å), the showed an orthorhombic perovskite structure, while when Dy Ho larger Y3+, it a monoclinic B-type rare earth structure. Next, solution system LaHoxYb1-xO3 was investigated in order to clarify crystallochemical factor affecting structural transformation. The XRD...
本研究では，フミン酸と銅の結合を考慮し，銅の藻類の生長阻害性のフミン酸の影響を定量的に調べた。まず，水素イオンと銅イオンのフミン酸への結合をNICA（non-ideal competitive adsorption）-Donnan Modelによって解析した。構築したモデルを用いて様々なpHにおけるフミン酸への銅の結合を予測し，次に，構築したモデルを用いて銅の藻類生長阻害性に対するフミン酸の影響を検証した。多摩川底質由来のフミン酸と市販のフミン酸とで銅の藻類の生長阻害性に対する影響が異なった。これは，多摩川底質のフミン酸がフルボ酸の性質に近く，市販のフミン酸と性質が異なっていることが考えられた。特に，フミン酸のカルボキシル基，フェノール基，ドナン相由来の3つの結合サイトの銅の結合量の総和に対し，結合力の強いフェノール基に結合した銅による藻類の生長阻害性への寄与は大きいと考えられた。
This study explores the complex relationship between soil electricity generating capacity, bacterial community dynamics, and chemical physical properties across diverse regions of Japan. First, samples were systematically collected analyzed. Subsequent investigations evaluated microbial biomass carbon, dissolved organic carbon (DOC), total dissolvable iron (DFeT) concentrations. In experiments, underwent a rigorous 60-day fuel cell trial, wherein power density energy output measured....
Stable high-voltage operation of LiCoPO4 (LCP) was successfully achieved via crystal-structure-matched surface coating using FePO4 (FP) with an identical olivine structure to the LCP. The efficient formation Fe3+-rich together partial dissolution Fe3+ into LCP matrix yielded excellent cycle performance 99% capacity retention at 100th cycle, a minimized dosage compared methods previously reported. This work confirms that existence on is important factor bring about stability...
LaLnO3 (Ln = Dy, Ho, Y, Er, and Yb) La(Ln, Ln')O3 (Ln, Ln' systems were synthesized by solid state reaction method characterized X-ray diffraction Rietveld analysis. In order to investigate the size effect of Ln site ion in ABO3-type compound, phase relationship system. When Er or Yb which has smaller ionic radius than that Y3+ (0.900 Å), showed an orthorhombic perovskite-type structure, while when Dy Ho larger Y3+, it a monoclinic B-type rare earth structure. Next, solution system...
1. Introduction Monoclinic Li 3 V 2 (PO 4 ) has promising features as a positive electrode for hybrid supercapacitors, such high thermal stabilities, three-dimensional path rapid ionic diffusion and potential of 3.9 vs . Li/Li + with decent capacity (131 mAh g -1 compared other polyanion-type materials olivine-type LiFePO (one-dimensional lithium ion diffusion, 3.4 ,170 ). One the challenges associated use cathodes is circumventing limitation their intrinsically low electronic conductivity....
1. Introduction Lithium cobalt phosphate (LiCoPO 4 ) with olivine structure has attracted much attention as a new positive electrode material for lithium ion batteries because of its high potential (4.8V vs. Li/Li + ), theoretical capacity (167 mAh g -1 and thermal stability due to the P-O covalent bonding. However, practical use LiCoPO been limited by fading during cycling electrolyte oxidation irreversible changes such amorphization anti-site defects charge discharge 1) . Besides, it...
This study explains the charge/discharge mechanism transformation from two-phase to a solid-solution reaction at over 4.5 V vs. Li/Li+ for monoclinic Li3V2(PO4)3 (LVP). An electrochemical characterization that combines galvanostatic cycling and intermittent titration technique confirms this occurs in LVP not only discharge (lithiation) as previously reported but also charge (delithiation), starting gradually within initial 10 cycles. A similar type of Li3V1.5Al0.5(PO4)3 (LVAP) indicates...
Electrical energy storage (EES) devices, in conjunction with technologies such as electric vehicles and renewable power sources, are crucial tools for efficient utilization of sustainable societies. Among different EES electrochemical capacitors, specifically supercapacitors (SCs), considered promising thanks to its high-power, safe long-lived characteristics. In order enhance the voltage density SCs while maintaining high power, a synthesis nanocomposites active materials homogeneous...
1. Introduction One promising strategy of increasing the energy density electric double layer capacitors (EDLCs) is design hybrid supercapacitors, which combine an activated carbon (AC) electrode with made from a high-capacity faradic (or pseudocapacitive) material such as lithium titanate (Li 4 Ti 5 O 12 , LTO). We have previously reported LTO//AC capacitor system—called Nanohybrid Capacitor —shows 3-fold (30 Wh L -1 ) EDLC, while attaining high power (6,000 W comparative to EDLC. 1) To...