Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials: Complicated Ceramics and Layered Nanomaterials
Sponsored by: ACerS Basic Science Division, ACerS Electronics Division, ACerS Engineering Ceramics Division
Program Organizers: Haitao Zhang, University of North Carolina at Charlotte; Gurpreet Singh, Kansas State University; Kathy Lu, Virginia Tech; Edward Gorzkowski, Naval Research Laboratory ; Jian Shi, Rensselaer Polytechnic Institute; Kejie Zhao, Purdue University ; Michael Naguib , Tulane University; Sanjay Mathur, University of Cologne
Monday 2:00 PM
November 2, 2020
Room: Virtual Meeting Room 26
Location: MS&T Virtual
Session Chair: Edward Gorzkowski, Naval Research Laboratory ; Michael Naguib, Tulane University
2:00 PM
Light Transmission Modulation in Ceramics through Mesoscale Modelling: Lukasz Kuna1; James Wollmershauser2; John Mangeri3; Boris Feigelson2; Edward Gorzkowski2; Serge Nakhmanson1; 1University of Connecticut; 2Naval Research Laboratory; 3Institute of Physics, Academy of Sciences of the Czech Republic
Mechanical property improvements by reducing the grain size is a well-known phenomenon called the Hall-Petch relationship. Advances in ceramic sintering processing has allowed the opportunity to explore the limits of those property improvements and re-evaluation of other grain size dependent phenomena, such as optical and dielectric properties. A novel modeling approach for simulating properties of polycrystalline ceramics with coupled optical, elastic and dielectric degrees of freedom has been developed at UConn, which allows for the determination of the dependency of optical properties on the microstructure, as well as temperature and action of externally applied electric fields and elastic strains. The computational approach can also predict the modulation of transmittance under applied stimuli, showing changes from full transparency to opacity in some cases. The results highlight a remarkable promise of functional nano- and micro-ceramics for a range of advanced engineering applications, including armor, multi-functional optics and metamaterials by design.
2:20 PM Invited
Chemical Pre-intercalation Synthesis and Exfoliation of Bilayered Vanadium Oxides for Energy Storage Applications: Ekaterina Pomerantseva1; 1Drexel University
Chemical pre-intercalation synthesis approach is based on low-temperature sol-gel process and it involves incorporation of inorganic or organic ions into the structure of the growing oxide phase prior to electrochemical cycling. In this presentation, I will show that chemical pre-intercalation is a versatile method that can be used for the synthesis of a wide family of new oxide phases with layered structures. I will present the effect of chemically preintercalated ions on electrochemical performance of these new electrode materials in intercalation batteries. Stabilization effect enabled by the insertion of electrochemically inactive ions will be discussed. Additionally, effect of low-temperature annealing on electrochemical stability and rate capability will be shown. I will also demonstrate the first exfoliation of bilayered vanadium oxide leading to the formation of free-standing films composed of ultrathin nanoflakes. The materials and methods developed in this work have the potential to enable next-generation energy storage technologies.
2:50 PM
d-Spacing Effect on the Electrochemical Performance of MXene in Organic and Room Temperature Ionic Liquids: Kun Liang1; Naresh Osti2; Eugene Mamontov2; Bishnu Thapaliya3; Sheng Dai2; Michael Naguib1; 1Tulane University; 2Oak Ridge National Laboratory; 3University of Tennessee
MXenes exhibit excellent capacitance at high rates in aqueous electrolytes specially in H2SO4 aqueous electrolyte, but in a narrow potential window, which limits the energy density. Moreover, oxidation of Ti3C2 under high anodic potentials in aqueous electrolytes further limits its use to cathodes of asymmetric devices. Organic electrolyte and room temperature ionic liquids (RTIL) can provide higher potential window, leading higher energy density and open circuit potential. In this work, different chain length alkylammonium cations were intercalated into Ti3C2Tz, producing different interlayer spacing (d-spacing). 1 M 1-ethly-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) in acetonitrile (ACN) and neat EMITFSI were employed as electrolytes to investigate the d-spacing effects on electrochemical performance for three-electrode system. As a result, alkylammonium cations intercalated Ti3C2Tz, AA-Ti3C2, provides much broad operating window, showing much higher specific capacitances, energy/power densities, and cycling stability than pristine Ti3C2Tz in 1 M EMITFSI/ACN organic electrolyte and neat EMITFSI RTIL electrolyte.
3:10 PM
Effect of Cation Pre-intercalation on the Electrochemical Performance of Multilayer Ti3C2 MXene in Aqueous Electrolyte: Kaitlyn Prenger1; Ameer Al-Temimy2; Kun Liang1; Simone Raoux2; Tristan Petit2; Michael Naguib1; 1Tulane University; 2Helmholz-Zentrum Berlin für Materialien und Energie GmbH
Electrically conductive 2D transition metal carbides/nitrides (MXenes) have enormous potential for electrochemical energy storage, as they can host ions and protons and possess high electrical conductivity. While delaminated Ti3C2 MXene paper has high capacitance, areal capacitance is limited. Multilayer Ti3C2 shows modest values overall. Herein, we present the electrochemical performance of multilayer Ti3C2 MXene pre-intercalated with cations (Na+, K+, Mg2+)in H2SO4. At 5 A/g, gravimetric capacitance of 325 F/g was achieved, comparable to delaminated Ti3C2 electrodes, but much higher than reported for multilayer MXene. Moreover, areal capacitance up to 2 F/cm2 was achieved. Intercalated multilayer Ti3C2 yields an easier avenue for making Ti3C2 supercapacitor electrodes with high areal capacitance. X-ray absorption spectroscopy shows that changing cations between layers alters the oxidation state of titanium atoms in Ti3C2, whereas dispersing Ti3C2 in H2SO4 resulted in reducing the surface titanium atoms. These results encourage further investigation into modifying Ti3C2 interlayer chemistry.