10 results on '"Kia Chai Phuah"'
Search Results
2. Anion Control of the Electrolyte Na3–xSbS4–xBrx Extends Cycle Life in Solid-State Sodium Batteries
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Stefan Adams, Kia Chai Phuah, and Xin Zhang
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Materials science ,chemistry ,General Chemical Engineering ,Sodium ,Inorganic chemistry ,Materials Chemistry ,Fast ion conductor ,Solid-state ,Ionic conductivity ,chemistry.chemical_element ,General Chemistry ,Electrolyte ,Ion - Abstract
Among the solid electrolytes studied for all-solid-state sodium batteries (ASSBs), Na3SbS4 (NAS) appears particularly promising due to its unique combination of high ionic conductivity and compatib...
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- 2021
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3. Bond Valence Pathway Analyzer—An Automatic Rapid Screening Tool for Fast Ion Conductors within softBV
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Lee Loong Wong, Ruoyu Dai, Stefan Adams, Kia Chai Phuah, Wee Chew, and Haomin Chen
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Spectrum analyzer ,Materials science ,Valence (chemistry) ,business.industry ,General Chemical Engineering ,Ionic bonding ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Materials Chemistry ,Fast ion conductor ,Optoelectronics ,Screening tool ,0210 nano-technology ,business ,Electrical conductor - Abstract
Solid-state fast ionic conductors are of great interest due to their application potential enabling the development of safer high-performance energy and conversion systems ranging from batteries th...
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- 2021
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4. Round-Trip Efficiency Enhancement of Hybrid Li-Air Battery Enables Efficient Power Generation from Low-Grade Waste Heat
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Kia Chai Phuah, Stefan Adams, Dongxiao Ji, Seeram Ramakrishna, and Dorsasadat Safanama
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Battery (electricity) ,Electricity generation ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,Waste heat ,Energy density ,Environmental Chemistry ,Environmental science ,General Chemistry ,Energy storage ,Automotive engineering ,Efficient energy use ,Power (physics) - Abstract
The superior energy density renders hybrid Li-air batteries (HLABs) promising candidate energy storage systems to enhance the sustainability of power grids. Nevertheless, HLABs operated at ambient ...
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- 2020
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5. Mechanochemical synthesis of fast sodium ion conductor Na11Sn2PSe12enables first sodium–selenium all-solid-state battery
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Kia Chai Phuah, R. Prasada Rao, Stefan Adams, and Xin Zhang
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Materials science ,Renewable Energy, Sustainability and the Environment ,Annealing (metallurgy) ,Sodium ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Electrolyte ,021001 nanoscience & nanotechnology ,chemistry.chemical_compound ,chemistry ,Selenide ,Ionic conductivity ,General Materials Science ,0210 nano-technology ,Tin ,Ball mill ,Current density - Abstract
Fast sodium ion conducting Na11Sn2PSe12 solid electrolyte was prepared by a mechanochemical method. This is the first tin based selenide prepared by room temperature ball milling instead of conventional synthesis in a sealed quartz tube under vacuum. Our approach is safe and easy to scale up. Samples were synthesized systematically using various intervals of ball milling and annealing time to maximise phase purity and ionic conductivity. The highest room temperature bulk ionic conductivity of the mechanochemically synthesized Na11Sn2PSe12 was 1.0 mS cm−1 observed for a sample prepared by ball milling for 15 h followed by 6 h annealing at 550 °C. This fast-ion conducting Na11Sn2PSe12 allowed to demonstrate the first Na–Se all-solid-state batteries Na/Na11Sn2PSe12/C–Se and Na3Sn/Na11Sn2PSe12/C–Se with specific initial discharge capacities of 430 mA h g−1 or 400 mA h g−1, respectively at a current density 0.08 mA cm−2. The Na3Sn/Na11Sn2PSe12/C–Se battery could be cycled 500 times with a capacity that decreased gradually to 50 mA h g−1.
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- 2019
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6. Enhanced Li
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Guang, Yang, Dorsasadat, Safanama, Kia Chai, Phuah, and Stefan, Adams
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equipment and supplies ,Article - Abstract
NASICON-type Li1+xAlxGe2–x(PO4)3 (LAGP) is a promising electrolyte with high ionic conductivity (>10–4 S cm–1), excellent oxidation stability, and moderate sintering temperature. However, preparing dense LAGP pellets with high ionic conductivity is still challenging because of the hazards of dopant loss and partial decomposition on conventional sintering. Here, spark plasma sintering (SPS) of LAGP membranes is explored as a promising ultrarapid manufacturing technique, yielding dense electrolyte membranes. Optimizing the SPS temperature is important to achieve desirable density and hence ionic conductance. Our results show that LAGP samples spark plasma-sintered at 750 °C exhibit the highest total ionic conductivity of 3.9 × 10–4 S cm–1 with a compactness of 97% and nearly single-crystalline particles. Our solid-state NMR results, X-ray diffraction studies, and scanning electron microscopy micrographs confirm that the achievable ionic conductivity is controlled by the retention of the Al dopant within the LAGP phase, necking between particles, and the minimization of grain boundaries between crystallites within a particle. To benchmark the performance of our spark plasma-sintered solid electrolyte membranes over conventionally prepared LAGP, we demonstrate their favorable performance in hybrid Li–air batteries. The highest energy efficiency is achieved for the fastest ion-conducting membrane sintered at 750 °C.
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- 2020
7. Determining Li+-Coupled Redox Targeting Reaction Kinetics of Battery Materials with Scanning Electrochemical Microscopy
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Thuan Nguyen Pham Truong, Qing Wang, Ruiting Yan, Hyacinthe Randriamahazaka, Jalal Ghilane, Stefan Adams, Kia Chai Phuah, Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS (UMR_7086)), Université Paris Diderot - Paris 7 (UPD7)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
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Battery (electricity) ,Materials science ,020209 energy ,Kinetics ,chemistry.chemical_element ,[CHIM.MATE]Chemical Sciences/Material chemistry ,02 engineering and technology ,Chronoamperometry ,Redox ,Chemical kinetics ,Scanning electrochemical microscopy ,Reaction rate constant ,Chemical engineering ,chemistry ,0202 electrical engineering, electronic engineering, information engineering ,[CHIM]Chemical Sciences ,General Materials Science ,Lithium ,Physical and Theoretical Chemistry ,ComputingMilieux_MISCELLANEOUS - Abstract
The redox targeting reaction of Li+-storage materials with redox mediators is the key process in redox flow lithium batteries, a promising technology for next-generation large-scale energy storage. The kinetics of the Li+-coupled heterogeneous charge transfer between the energy storage material and redox mediator dictates the performance of the device, while as a new type of charge transfer process it has been rarely studied. Here, scanning electrochemical microscopy (SECM) was employed for the first time to determine the interfacial charge transfer kinetics of LiFePO4/FePO4 upon delithiation and lithiation by a pair of redox shuttle molecules FcBr2+ and Fc. The effective rate constant keff was determined to be around 3.70–6.57 × 10–3 cm/s for the two-way pseudo-first-order reactions, which feature a linear dependence on the composition of LiFePO4, validating the kinetic process of interfacial charge transfer rather than bulk solid diffusion. In addition, in conjunction with chronoamperometry measurement,...
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- 2018
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8. (Keynote) An Automatic Rapid Screening Tool for Fast Ionic Conductors
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Kia Chai Phuah, Xin Zhang, Anastassia Sorkin, Ruoyu Dai, Stefan Adams, and Haomin Chen
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Phase transition ,Molecular dynamics ,Valence (chemistry) ,Fast ion conductor ,Ionic conductivity ,Ionic bonding ,Thermodynamics ,Characterization (materials science) ,Ion - Abstract
Identifying new materials that combine high ionic conductivity with structural and electrochemical stability so far remains a slow trial and error search process. To rationally accelerate materials design and exploit the opportunities in the materials genome a dependable rapid screening of materials is required that can pre-select structures that merit higher level computational as well as experimental characterization. Here we report on the progress of our “softBV” bond-valence site energy-based automated pathway analysis utilizing our new Bond Valence Pathway Analyzer (BVPA) – with fast bond valence site energy calculations to quickly obtain suggested candidate materials for fast ionic conduction. BVPA provides rapid and simplified visualization, in order to bridge the gap between experimentalists and simulation [1,2]. Calculation of ion transport pathways can be done extremely quickly on the order of seconds or minutes on desktop PCs providing a speedup factor of 3 to 5 orders of magnitude compared to DFT-based NEB methods. Combined with a graphical user interface our software suite (that can be downloaded from [2] and is free for academic use) should enable experimentalists to quickly identify candidate solid electrolyte materials. We also aim to integrate the pre-screening into an automated workflow for subsequent DFT characterization [3]. Results will be benchmarked against both experimental and DFT NEB migration barriers. Besides the migration barriers the approach now also comprises an AI-based dopant predictor utilizing bond-valence-based crystal chemical descriptors to assist experimentalists in exploring favorable substitutional doping strategies. We will also compare the predictability of absolute room temperature conductivities from static energy landscape analysis, bond-valence based empirical MD simulations and ab initio molecular dynamics (AIMD) simulations. While for small fast-ion conductor structures at sufficiently high temperatures AIMD appears to be the gold standard, the less reliable but computationally empirical approaches have an advantage in modelling complex disordered interfaces at low temperatures over longer periods. This eliminates the hazards involved in extrapolations down to room temperature properties for the frequent cases of order-disorder phase transitions at intermediate temperatures. As an example we will discuss lithium and sodium compounds containing multiple anions, in particular the combination of thiophosphate and halide anions or various MS4 polyanions. Based on computational screening using our bond valence site approach and DFT studies several thiophosphate halides along the A3PS4-LiX (Cl, Br, I; A = Li, Na) tie line [4] and the Ax(MS4)y(M’S4)z phase space [5] have been explored and their properties discussed based on BVSE pathway models and molecular dynamics simulations in combination with experimental (X-ray and neutron) diffraction, solid state NMR and electrochemical characterisation. MD simulations e.g. show that Li5(PS4)Cl2 is found to undergo an order-disorder phase transition and thus should, contrasting to earlier predictions, not be a fast Li+ ion conductor. The newly predicted thermodynamically stable cubic solid electrolyte Li15(PS4)4Cl3 was successfully prepared and characterized. Though its conductivity does not reach a superionic level, it demonstrates that the computational approach can successfully predict a completely new classes of solid electrolytes and can predict its optimization by doping. The simplicity of the approach also facilitates the study of homogeneity ranges as exemplified for the solid solution systems Li4-xPS4Ix (09+x(MS4)3-x(SnS4)x (M = P, Sb; x ≈ 2). References: [1] L.L. Wong, K.C. Phuah, H. Chen, W.S. Chew, R. Dai, S Adams; submitted. [2] http://www.dmse.nus.edu.sg/asn/software.html [2] B. He, S. Chi, A. Ye et al.; accepted in npj Scientific Data 2020. [3] R. Prasada Rao, H. Chen, S. Adams; Chemistry of Materials 31 (2019) 8649-8662. [4] A. Sorkin, S. Adams, accepted in Materials Advances 2020.
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- 2020
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9. Determining Li
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Ruiting, Yan, Jalal, Ghilane, Kia Chai, Phuah, Thuan Nguyen, Pham Truong, Stefan, Adams, Hyacinthe, Randriamahazaka, and Qing, Wang
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The redox targeting reaction of Li
- Published
- 2018
10. Enhanced Li1+xAlxGe2-x (PO4)3 Anode-Protecting Membranes for Hybrid Lithium-Air Batteries by Spark Plasma Sintering.
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Guang Yang, Dorsasadat Safanama, Kia Chai Phuah, and Adams, Stefan
- Published
- 2020
- Full Text
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