Materials for Sustainability and Energy

Conference: 2021: 71st ACA Annual Meeting
08/01/2021: 12:00 PM - 3:00 PM
1.2.2 
Oral Session 
Virtual  

Description

Crystallography lays the foundations for understanding the structure-property relationship of functional materials for energy and sustainability. Design and optimization of materials for energy conversion and storage technologies, such as batteries, fuel cell, thermoelectrics and solar cell, relies upon insight of the crystal structure. This session will cover the latest development in the cross disciplinary fields of crystallography and materials science, so as to provide a discussion on the recent advance in the structural studies.

Presentations

Crystal Structure and Structure-Property Relationship of Halide Superionic Conductors as Solid Electrolyte for All-Solid-State Batteries

All-Solid-State Batteries are a promising next-generation electrochemical energy storage technology that may replace current Li-ion batteries in the future, owing to their outstanding safety properties and high energy density. Currently its electrochemical performance and commercialization are majorly limited by the relative low performance of the solid electrolyte. Solid electrolytes with high ionic conductivity, low electronic conductivity, good chemically and elelectrochemically stability and low manufacture cost are much desired. In last two years, a group of lithium containing halides with a general formula Li3MX6 (M=Y, Sc, and In, etc.; X=Br or Cl) attracted much attention as they are more all-around candidate for solid electrolyte than existing oxide and sulfide electrolytes. They are more chemical and electrochemically stable than sulfides and are much easier to synthesize. They also showed much higher ionic conductivity than that of oxides. However, their room temperature ionic conductivity is still lower than state-of-the-art sulfide electrolytes by one order of magnitude. To improve their ionic conductivity, it is critically important to understand the structure-property relationship and find the ionic conductivity governing factors in this group of compounds. Here we will share our recent research results on elucidating the crystal structure of Li3YBr3Cl3 and related compounds with using synchrotron X-ray and neutron diffraction and pair distribution function analysis. We identified the existence of Li at the tetrahedral sites in the lattice, which were not reported previously. The existence of tetrahedral Li has significant impact on the energy landscape of the Li sublattice and the diffusion energy barriers in all three dimensions, which in part results in the very high room temperature ionic conductivity of 7.2 mS/cm and a very low diffusion energy barrier of 0.25 eV. The performance of all-solid-state batteries with using Li3YBr3Cl3 as the electrolyte and the design guidelines will also be discussed. 

View Abstract 694

Author

Hailong Chen

High entropy multication rock salt oxides for lithium ion batteries

High entropy oxides (HEOs) are solid state inorganic compounds in which entropy, rather than enthalpy, plays a dominant role in stabilizing a single-phase structure at high temperatures. This work has been motivated in part by prior studies of multicomponent alloys in which four or more cations occupy the same crystallographic site in equal proportions, known as high entropy alloys (HEAs), which have superior mechanical properties and high radiation tolerances due in part to high configurational entropy.[1] In the case of HEOs, the first example is the rock salt (Mg0.2Ni0.2Co0.2Cu0.2Zn0.2)O, which has generated a great deal of interest in this class of materials.[2,3] We have recently demonstrated that HEOs prepared by mechanochemical synthesis can be prepared in pure form, and may be useful for catalysis.[4,5] It has also been shown that HEOs are of interest for high ionic conductivity and electrochemical energy storage.[6,7] In this study, we have examined the electrochemical cycling of new high entropy rock salt phases versus lithium, and found an effect of composition on the cycling performance. Samples were prepared through high energy milling of starting binary oxides, which proceed to decompose and then reform pure compounds at high temperature. We have confirmed that entropy plays a role in this transformation for these rock salt HEOs, and that the precise composition has an impact on the temperature and kinetics of pure phase formation; investigations of the synthesis and subsequent decomposition have been conducted in our laboratory using high temperature in-situ X-ray diffraction on a Panalytical diffractometer equipped with an XRK900 stage. STEM/EDS studies on quenched ex-situ samples will be presented that show how elemental segregation occurs as a function of temperature. The results of this study will be highly impactful for the growing community of researchers investigating the design and synthesis of the new class of materials, the high entropy oxides.

[1] Y. Lu, et. al., Sci. Rep. 4, 6200 (2014); Y. F. Ye, et. al., Mater. Today 19 (6), 349 (2016); Zhang, Y., et. al., Nature Commun. 6, 8736 (2015); [2] C. M. Rost, et. al., Nature Commun. 6, 8485 (2015); [3] B. Jiang, et. al., Probing the Local Site Disorder and Distortion in Pyrochlore High-Entropy Oxides. Journal of the American Chemical Society 2021, 143, (11), 4193-4204; [4] H. Chen, et al., Mechanochemical Synthesis of High Entropy Oxide Materials under Ambient Conditions: Dispersion of Catalysts via Entropy Maximization, ACS Materials Lett. 2019, 1, 1, 83–88; [5] H. Chen, et. al., Entropy-stabilized metal oxide solid solutions as CO oxidation catalysts with high-temperature stability, J. Mater. Chem. A 2018, 6, 11129-11133; [6] Q. Wang, et. al., Multi-anionic and -cationic compounds: new high entropy materials for advanced Li-ion batteries, Energy Environ. Sci., 2019, 12, 2433; [7] D. Berardan, et. al., Room temperature lithium superionic conductivity in high entropy oxides, J. Mater. Chem. A, 2016, 4, 9536. 

View Abstract 653

Author

Craig Bridges, Oak Ridge National Laboratory Oak Ridge, TN 

Additional Author(s)

Bishnu Thapaliya, ORNL Oak Ridge, TN 
Sheng Dai, ORNL Oak Ridge, TN 
Albina Borisevich, ORNL Oak Ridge, TN 

Coffee Break


Probing Structural Attributes for Li-Argyrodite as a Fast Ion Conductor using Neutron Powder Diffraction

Driven by technological importance, the development of all-solid-state lithium-ion batteries has awakened the pursuit of solid electrolytes with superior Li+ conductivity. Li-Argyrodite is a unique player in the field of solid electrolytes because this sulfide-based material was shown to achieve an ionic conductivity of 24 mS/cm at room temperature. This record, which even outperforms the liquid electrolyte (~ 10 mS/cm at r.t.), calls for an understanding of the origin of fast ion conduction in Li-Argyrodite. In this work, we employ variable-temperature neutron diffraction and impedance spectroscopy to investigate the structural attributes for Li+ transport properties in Li-Argyrodite, Li6PS5X (X = Cl, Br, and I). Structural analyses based on the Rietveld refinements, maximum entropy method (MEM) analysis, and bond valence site energy (BVSE) reveal that Li+ has the potential to take an interstitial site 16e, enabling a cage-to-cage three-dimensional Li+ conduction via 48h–16e–48h pathway. In addition, we find that the anion site disorder between S2– and X, which is commonly perceived as the key factor to promote Li+ conductivity, is fundamentally correlated with the negative charge distribution over the anion 4a and 4c sites. Learned from this understanding, we further show that tuning the negative charge ratio of 4a and 4c to unity is an effective approach to realizing higher Li+ conductivity in Li5.7PS4.7ClBr0.3

View Abstract 537

Author

Po-Hsiu Chien Knoxville, TN 

Additional Author(s)

Xuyong Feng, The Walker Department of Mechanical Engineering, The University of Texas at Austin Austin, TX 
JUE LIU, Oak Ridge National Laboratory Oak Ridge, TN 

Exploring aliovalent substitutions in the lithium halide superionic conductor Li3-xIn1-xZrxCl6 (0 ≤ x ≤ 0.5)

Over the last years, the attention for the search of superionic materials shifted to the ternary rare-earth metal halides Li3MX6 (M = Y, Er, In; X = Cl, Br, I) because of their promising high room-temperature conductivities. To date, the influence of iso- or aliovalent substitutions within this material class is rarely understood due to the absence of substitution studies in the ternary halides which are a common tool to link changes in structure with the observed ionic transport. In this work, we investigate the impact of Zr substitution on the structure and ionic conductivity of Li3InCl6 (Li3-xIn1-xZrxCl6 with 0 ≤ x ≤ 0.5) using a combination of neutron diffraction, nuclear magnetic resonance and impedance spectroscopy. Analysis of high-resolution neutron diffraction data indicates a cation-site disorder as well as an additional tetrahedrally coordinated site, which has not been reported in Li3InCl6 yet. The newly introduced Li+ positions and the already known Li+ positions form a three-dimensional polyhedral network and therefore 3D diffusion is enabled. The Zr4+ substitution within Li3InCl6 induces non-uniform volume changes and increases the number of vacancies in the structure, all of which lead to an increasing ionic conductivity in this series of solid solutions. 

View Abstract 560

Author

Bianca Helm, University of Muenster Muenster

Additional Author(s)

Roman Schlem, University of Muenster Muenster
Björn Wankmiller, University of Muenster Muenster
Ananya Banik, University of Muenster Muenster
Ajay Gautam, Justus-Liebig-University of Giessen Giessen
Justine Ruhl, Justus-Liebig-University of Giessen Giessen
Cheng Li, Oak Ridge National Laboratory Oak Ridge, TN 
Michael Hansen, University of Muenster Muenster
Wolfgang Zeier, University of Muenster Muenster

Salt Effects on Li-ion Exchange Kinetics and Activation Energies – Systematic In Situ Synchrotron Diffraction Studies

Solid state ionic conduction plays a central role in the functionality of many energy materials, including the cathodes being used in the present generation of battery technologies and the solid state electrolytes being considered for the next generation of batteries. Solid state ion exchange of Li+ into Na2Mg2P3O9N was investigated using in situ synchrotron powder X-ray diffraction. By using a 2D area detector many samples were studied simultaneously in novel high throughput studies of ion exchange reactions. Kinetic rate constants were extracted from the time-dependent evolution of lattice parameters. Reactions were followed using a novel on-the-fly Rietveld refinement tool which enabled real time monitoring of reaction progress. The ion exchange rates were found to be limited by the ion transport in the salt rather than the host ceramic. From this data, it was seen that reaction rates substantially varied with salt concentration in a manner than appears to follow a universal scaling relationship. By carrying out experiments at different temperatures, activation energies for reactions could be precisely determined. The origin of the experimentally observed activation energies is being investigated through DFT studies. 

View Abstract 527

Author

Monty Cosby Stony Brook, NY 

Additional Author(s)

Christopher Bartel, University of California, Berkeley Berkeley, CA 
Adam Corrao, Stony Brook University Stony Brook, NY 
Andrey Yakovenko, Argonne National Laboratory Lemont, IL 
Leighanne Gallington, X-ray Science Division, Argonne National Lab Argonne, IL 
Gerard Mattei, Stony Brook University Stony Brook, NY 
Karena Chapman, Stony Brook University Stony Brook, NY 
Gerbrand Ceder, Lawrence Berkeley National Laboratory Berkeley, CA 
Peter Khalifah, Chemistry, Stony Brook Univ Stony Brook, NY 

Isoreticulation of Zwitterionic Metal-Organic Frameworks for Electrochromic Applications

Metal-organic frameworks (MOFs) are crystalline porous materials composed of metal ions or clusters connected by functionality-tunable polytopic organic linkers producing three-dimensional porous structures affording high surface area to mass ratios and large pore volumes rendering MOFs as the perfect platform for diverse host-guest chemistry. This work entails the design, synthesis, and characterization of a series of linear pyridinium and carboxylate based zwitterionic ligands with particular attention to the identities of the terminal coordinating functional groups, maintaining identical charges, built-in functional groups, and the location of the N+ atom of the pyridinium ring. Using these ligands, a series of isoreticular zwitterionic MOFs were synthesized through varying the identity of the metal salts and co-ligands used. Modern solid state analytical techniques were employed to obtain important structure-property relationship information of these MOFs with focus on their electrochromic and/or photochromic properties for smart window technologies, and selective gas adsorption properties for carbon capture. 

View Abstract 542

Author

John hadynski, Clarkson University Potsdam, NY 

Additional Author

Mario Wriedt, Clarkson University Potsdam, NY 

Understanding Selective Propane/Ethane Gas Adsorption using Neutron Diffraction

Metal organic frameworks (MOFs) offer considerable uses for gas uptake and storage due to their porous nature, chemical tunability, and flexibility. One particular MOF, MUF-16, has recently shown exceptionally high selectivity for carbon dioxide., allowing for potential decreases in energy cost for gas separations. In addition, this MOF also more readily adsorbs propane/propene over ethane/ethylene due to inherent structural flexibility, at STP conditions. We used a combination of in-situ synchrotron X-ray and Neutron diffraction to better understand the structural flexibility and gas interactions. Inelastic neutron scattering, along with calculations, was also conducted to understand the dynamics of the flexibility, highlighting that C3 molecules more effectively bridge across the framework, inhibiting some types of motion in the material. 

View Abstract 699

Author

Benjamin Trump, NIST Center for Neutron Diffraction Bethesda, MD 

Additional Author(s)

Omid Taheri, Postdoctoral Studen Palmerston North
Shane Telfer, Professor Palmerston North
Craig Brown, NIST Gaithersburg, MD