A5091023967- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Hydrogen Storage and Materials
- Ammonia Synthesis and Nitrogen Reduction
- Semiconductor materials and interfaces
- Magnesium Alloys: Properties and Applications
- Superconductivity in MgB2 and Alloys
- Advanced Battery Technologies Research
- Extraction and Separation Processes
- Semiconductor materials and devices
- Supercapacitor Materials and Fabrication
- Thermal Expansion and Ionic Conductivity
- MXene and MAX Phase Materials
- Boron and Carbon Nanomaterials Research
- Rare-earth and actinide compounds
- Nanomaterials for catalytic reactions
- Magnetic Properties of Alloys
- Electrocatalysts for Energy Conversion
- Advancements in Solid Oxide Fuel Cells
- Hybrid Renewable Energy Systems
- Fuel Cells and Related Materials
- Fusion materials and technologies
- Advanced NMR Techniques and Applications
- Graphene research and applications
- Muon and positron interactions and applications
University of Alberta
2011-2022
National Institute for Nanotechnology
2010-2020
National Research Council Canada
2010-2020
University of British Columbia
2015
Eindhoven University of Technology
2005-2009
Banana peel pseudographite (BPPG) offers superb dual functionality for sodium ion battery (NIB) and lithium (LIB) anodes. The materials possess low surface areas (19-217 m(2) g(-1)) a relatively high electrode packing density (0.75 g cm(-3) vs ∼1 graphite). Tested against Na, BPPG delivers gravimetric (and volumetric) capacity of 355 mAh g(-1) (by active material ∼700 cm(-3), by volume ∼270 cm(-3)) after 10 cycles at 50 mA g(-1). A nearly flat ∼200 plateau that is below 0.1 V minimal...
Here we provide the first report on several compositions of ternary Sn–Ge–Sb thin film alloys for application as sodium ion battery (aka NIB, NaB or SIB) anodes, employing Sn50Ge50, Sb50Ge50, and pure Sn, Ge, Sb baselines. Sn33Ge33Sb33, Sn50Ge25Sb25, Sn60Ge20Sb20, Sn50Ge50 all demonstrate promising electrochemical behavior, with Sn50Ge25Sb25 being best overall. This alloy has an initial reversible specific capacity 833 mAhg–1 (at 85 mAg–1) 662 after 50 charge–discharge cycles. also shows...
A simple methodology is developed to directly synthesize three-dimensional (3D) electrochemically supercapacitive arrays, consisting of multiwalled carbon nanotubes conformally covered by nanocrystalline vanadium nitride, firmly anchored glassy or Inconel electrodes. These nanostructures demonstrate a respectable specific capacitance 289 F g–1, which achieved in 1 M KOH electrolyte at scan rate 20 mV s–1. The well-connected highly electrically conductive structures exhibit superb capability;...
The cycling stability of Sb-based anodes for sodium-ion batteries can be greatly improved by adding Sn and Bi atoms in a substitutional solid solution with the host Sb lattice.
Germanium is a promising sodium ion battery (NIB, NAB, SIB) anode material that held back by its extremely sluggish kinetics and poor cyclability. We are the first to demonstrate activation single lithiation-delithiation cycle leads dramatic improvement in practically achievable capacity, rate capability, cycling stability of Ge nanowires (GeNWs) thin film (GeTF). TEM TOF-SIMS analysis shows without activation, initially crystal GeNWs effectively Na inactive, while 100 nm amorphous GeTF...
β-SnSb is known to be a highly stable anode for sodium ion batteries during cycling, but its sodiation–desodiation alloying reactions are poorly understood. Combining in situ TEM with electroanalytical methods, we demonstrate that forms Na3Sb and Na15Sn4 sequence upon sodiation re-forms as desodiation. The negative enthalpy of mixing Sn Sb sufficient cause sequentially deposited bilayers Sn/Sb transform into β-SnSb, resulting comparable cycling stability. good stability results from the...
We investigated the effect of aluminum coating layers and support growth substrates on electrochemical performance silicon nanowires (SiNWs) used as negative electrodes in lithium ion battery half-cells. Extensive TEM SEM analysis was utilized to detail cycling induced morphology changes both Al-SiNW nanocomposites baseline SiNWs. observed an improved Si that were coated with 3 8 wt.% aluminum. After 50 cycles, bare Al retained 2600 mAh/g capacity. However beyond showed higher capacity well...
Silicon has a theoretical sodium-storage capacity of 954 mAh/g, which even exceeds that tin (847 mAh/g). However, this never been reached in practice. Antimony is one the best-performing Na-storage materials terms both and cycling stability. By combining silicon antimony, either by cosputtering or depositing multilayers with bilayer thickness down to 2 nm, we can achieve capacities exceeding Sb (660 Minor addition silicon, 7 at. % wt (25 %), increases measured reversible from 625 mAh/g for...
A series of hydrogen rich Mg6–7TMH14–16 (TM = Ti, Zr, Hf, V, Nb and Ta) hydrides have been synthesized at 600 °C in a high pressure anvil cell above 4 GPa. All structures based on fluorite type metal atom subcell lattice with ≈ 4.8 Å. The TM arrangements are, however, more ordered can best be described by superstructure where the Å FCC unit axis is doubled. full structure corresponds to Ca7Ge structure. This was also observed from electron diffraction patterns. atoms were found powder X-ray...
Silicon is recognized as a promising anode material for high-performance lithium ion batteries due to its high theoretical specific capacity and elemental abundance. Challenges related the low electrical conductivity of Si large volume changes during lithiation/delithiation cycles, well rate diffusion in silicon anodes, hinder practical applications. To provide fundamental insights into these issues, nanocrystal/graphene aerogel nanocomposites were synthesized by combining undecanoic...
Scientific literature shows a substantial study-to-study variation in the electrochemical lithiation performance of “1-D” nanomaterials such as Si and Ge nanowires or nanotubes.
Group IV of the periodic table is a promising column with respect to high capacity anode materials for sodium-ion batteries (SIBs). Unlike carbon which relies on interlayer defects, pores, and intercalation store sodium, its heavier cousins—silicon, germanium, tin—form binary alloys sodium. Alloying does lead formation high-capacity compounds, but they are, however, susceptible large volumetric changes upon expansion that results in pulverization electrodes poor cycling stability. Silicon...
Water uptake and swelling in a thin (∼15 nm) Nafion film on SiO2 native oxide Si wafer is studied as function of relative humidity (8-97%) at room temperature (25-60 °C) 97% by neutron reflectometry. This the first report behavior films elevated temperatures high humidity. Large hysteresis observed during cycle. The strain 60 °C 48% compared to as-deposited state, which far above any previously trend temperature. A small decrease average SLD suggests that part additional due thermal...
Silicon-based anodes for Li-ion batteries have been gaining a great deal of attention due to their high theoretical gravimetric energy density. Approaches overcoming the challenge pulverization associated with Si-based electrodes are required efficient, reversible, and stable operation such batteries. This study focuses on addressing source amorphous silicon films upon cycling, which is typically attributed formation c-Li3.75Si phase. Cross-sectional samples prepared by focused-ion beam...
Magnesium transition-metal alloys have a high hydrogen-storage capacity and show improved hydrogen-uptake -release kinetics compared to magnesium alone. In the present study we investigated structure of bulk magnesium-titanium deuteride ${\text{Mg}}_{0.65}{\text{Ti}}_{0.35}{\text{D}}_{x}$ prepared via mechanical alloying gas-phase deuterium absorption by combined use x-ray diffraction (XRD), neutron diffraction, magic-angle-spinning $^{2}\text{H}$ nuclear magnetic resonance (NMR). The...