A5100458863- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Advanced Battery Technologies Research
- Semiconductor materials and devices
- Supercapacitor Materials and Fabrication
- Extraction and Separation Processes
- Electron and X-Ray Spectroscopy Techniques
- Advanced battery technologies research
- Transition Metal Oxide Nanomaterials
- Corrosion Behavior and Inhibition
- Ferroelectric and Piezoelectric Materials
- Electrochemical Analysis and Applications
- Machine Learning in Materials Science
- Catalytic Processes in Materials Science
- Boron and Carbon Nanomaterials Research
- Hydrogen embrittlement and corrosion behaviors in metals
- Oil Spill Detection and Mitigation
- Semiconductor Lasers and Optical Devices
- Electronic Packaging and Soldering Technologies
- Electrocatalysts for Energy Conversion
- Pickering emulsions and particle stabilization
- NMR spectroscopy and applications
- Advanced NMR Techniques and Applications
Binghamton University
2019-2025
Karlsruhe Institute of Technology
2022-2024
University of California, San Diego
2024
Tsinghua University
2024
Dalian Maritime University
2005-2023
Hefei University of Technology
2023
Wuhan University of Science and Technology
2023
Huawei Technologies (China)
2023
Jiaxing University
2022
Jinzhong University
2022
The absence of a phase transformation involving substantial structural rearrangements and large volume changes is generally considered to be key characteristic underpinning the high-rate capability any battery electrode material. In apparent contradiction, nanoparticulate LiFePO4, commercially important cathode material, displays exceptionally high rates, whereas its lithium-composition diagram indicates that it should react via kinetically limited, two-phase nucleation growth process....
Capacity fading has limited commercial layered Li-ion battery electrodes to <70% of their theoretical capacity. Higher capacities can be achieved initially by charging higher voltages, however, these gains are eroded a faster fade in Increasing lifetimes and reversible capacity contingent on identifying the origin this inform electrode design synthesis. We used operando X-ray diffraction observe how lithiation-delithiation reactions within LiNi0.8Co0.15Al0.05O2 (NCA) change after following...
Through operando synchrotron powder X-ray diffraction (XRD) analysis of layered transition metal oxide electrodes composition LiNi0.8Co0.15Al0.05O2 (NCA), we decouple the intrinsic bulk reaction mechanism from surface-induced effects. For identically prepared and cycled stored in different environments, demonstrate that for pristine NCA follows solid-solution mechanism, not a two-phase as suggested previously. By combining high resolution diffraction, diffuse reflectance infrared Fourier...
Solid-state batteries provide substantially increased safety and improved energy density when energy-dense alkali metal anodes are applied. However, most solid-state electrolytes react with metals, causing a continuous increase of the cell impedance. Here, we employ reactivity-driven strategy to improve interfacial stability between Na3SbS4 electrolyte sodium metal. First-principles calculations identify protective hydrate coating for that leads generation passivating decomposition products...
Nanosized, carbon-coated LiFePO4 (LFP) is a promising cathode for Li-ion batteries. However, nano-particles are problematic electrode design, optimized electrodes requiring high tap densities, good electronic wiring, and low tortuosity efficient Li diffusion in the electrolyte between solid particles, conditions that difficult to achieve simultaneously. Using situ energy-dispersive X-ray diffraction, we map evolution of inhomogeneous electrochemical reaction LFP-electrodes. On first cycle,...
Substituted Li-layered transition-metal oxide (LTMO) electrodes such as LixNiyMnzCo1–y–zO2 (NMC) and LixNiyCo1–y–zAlzO2 (NCA) show reduced first cycle Coulombic efficiency (90–87% under standard cycling conditions) in comparison with the archetypal LixCoO2 (LCO; ∼98% efficiency). Focusing on LixNi0.8Co0.15Al0.05O2 a model compound, we use operando synchrotron X-ray diffraction (XRD) nuclear magnetic resonance (NMR) spectroscopy to demonstrate that apparent first-cycle capacity loss is...
LiNi0.8Mn0.1Co0.1O2 (NMC811) is a promising cathode material for lithium-ion batteries (LIBs) in electric vehicle applications but faces severe capacity and voltage decay issues, especially when cycled at high voltages (>4.2 V) which essential to fully exploit its energy density. A portion of aged NMC811 becomes fatigued above 4.2 V, making further delithiation difficult limiting the charge window <74% lithium, contributes loss significant overpotential growth voltage. This fatigue...
The doping of Al into layered Li transition metal (TM) oxide cathode materials, LiTMO2, is known to improve the structural and thermal stability, although origin enhanced properties not well understood. effect aluminum on layer stabilization has been investigated using a combination techniques measure distribution in LiNi0.8Co0.15Al0.05O2 (NCA) over multiple length scales with 27Al 7Li MAS NMR, local electrode atom probe (APT) tomography, X-ray neutron diffraction, DFT, SQUID magnetic...
The emergence of oxidized oxygen RIXS features at high voltages for Ni-rich layered oxide cathodes.
In this work, we demonstrate the stable cycling of more than one Li in solid-state-synthesized ε-LiVOPO4 over 20 cycles for first time. Using a combination density functional theory (DFT) calculations, X-ray pair distribution function (PDF) analysis and absorption near edge structure (XANES) measurements, present comprehensive thermodynamics, kinetics, structural evolution ε-LixVOPO4 entire lithiation range. We identify two intermediate phases at x = 1.5 1.75 low-voltage regime using DFT...
Li–Fe antisite defects are commonly found in LiFePO4 particles and can impede or block Li diffusion the single-file channels. However, due to their low concentration (∼1%), effect of on has only been systematically investigated by theoretical approaches. In this work, exchange between solid (92.5% enriched with 6Li) liquid electrolyte solution (containing natural abundance Li, 7.6% 6Li 92.4% 7Li) was measured as a function time both ex situ solid-state nuclear magnetic resonance experiments....
In composite battery electrode architectures, local limitations in ionic and electronic transport can result nonuniform energy storage reactions. Understanding such reaction heterogeneity is important to optimizing performance, including rate capability mitigating degradation failure. Here, we use spatially resolved X-ray diffraction computed tomography map the a based on LiFePO4 active material as it undergoes charge discharge. Accelerated reactions at faces contact with either separator or...
We have demonstrated a molecular interface engineering strategy to address the design dilemma of low-temperature electrolytes for lithium metal batteries.
LiNi0.8Mn0.1Co0.1O2 (NMC811) is a popular cathode material for Li-ion batteries, yet degradation and side reactions at the cathode-electrolyte interface pose significant challenges to their long-term cycling stability. Coating LiNixMnyCo1-x-yO2 (NMC) with refractory materials has been widely used improve stability of interface, but mixed results have reported Al2O3 coatings Ni-rich NMC811 materials. To elucidate role effect coating, we coated commercial-grade electrodes by atomic layer...
Inhomogeneous Li intercalation and localized concentration reversal in nanoparticles are investigated on a nanometer scale.
Anisotropic disorder along the <italic>c</italic>-axis results from static disorder.
A tubular operando electrochemical cell has been developed to allow spatially resolved X-ray scattering and spectroscopic measurements of individual components, or regions thereof, during device operation. These are enabled by the geometry, wherein X-ray-transparent tube walls radial access for incident scattered/transmitted beam; probing different depths within electrode stack, transformation components can be resolved. The is compatible with a variety synchrotron-based scattering,...
Lithium transition metal oxides are an important class of electrode materials for lithium-ion batteries. Binary or ternary (transition) doping brings about new opportunities to improve the electrode's performance and often leads more complex stoichiometries atomic structures than archetypal LiCoO2. Rietveld structural analyses X-ray neutron diffraction data is a widely-used approach characterization crystalline materials. However, different models refinement approaches can lead differing...
The delithiation mechanisms occurring within the olivine-type class of cathode materials for Li-ion batteries have received considerable attention because good capacity retention at high rates LiFePO4. A comprehensive mechanistic study (de)lithiation reactions that occur when substituted LiFexCo1–xPO4 (x = 0, 0.05, 0.125, 0.25, 0.5, 0.75, 0.875, 0.95, 1) are electrochemically cycled is reported here using in situ X-ray diffraction (XRD) data and supporting ex 31P NMR spectra. On first...
A novel P2/tunnel/O3' composite Na0.7Bi0.01MnO2 cathode is developed via the Na+-site modification of Bi3+ in layer structure Na0.7MnO2 for first time. Superior electrochemical performance with a high capacity retention ∼86.5% after 300 cycles at 2C obtained. Moreover, tri-phase can also serve as model material, which intuitively evidences environmental structural stability order: tunnel > P2 O3'.
Atomic layer deposition (ALD) is a popular method of coating battery electrodes with metal oxides for improved cycling stability. While significant research has focused on the interaction between reactive alkyl precursor and electrode materials, little known about reactivity toward other components electrode, such as polymer binder. This study presents combined computational experimental investigation reaction polyvinylidene (PVDF) binder trimethylaluminum (TMA) commonly used Al2O3 by ALD....
The abundance of sodium makes Na-ion batteries a cheaper alternative to state-of-the-art Li-ion batteries. Similar batteries, operate by the intercalation Na ions in host lattice. Due larger ionic radius and higher effective charge ions, can often lead prominent ion-vacancy ordering significant structural transformation. While single-crystal diffraction would be ideal resolve these complex evolutions, large single crystals typically yield poor electrochemical behavior, thus not available...