Energy Materials for Sustainable Development: Thermal Conversion
Sponsored by: ACerS Energy Materials and Systems Division
Program Organizers: Krista Carlson, University of Nevada, Reno; Armin Feldhoff, Leibniz University Hannover; Kyle Brinkman, Clemson University; Eva Hemmer, University of Ottawa; Nikola Kanas, BioSense Institute; Kjell Wiik, Norwegian University of Science and Technology; Lei Zuo, Virgina Tech; Joshua Tong, Clemson University ; Danielle Benetti, Institut National de la Recherche Scientifique; Katherine Develos-Bagarinao, National Institute of Advanced Industrial Science and Technology; Soumi Chatterjee, Aditya Birla Science & Technology Company, Ltd

Wednesday 2:00 PM
October 12, 2022
Room: 413
Location: David L. Lawrence Convention Center

Session Chair: Jianhua Tong, Clemson University ; Javier Garay, University of California San Diego


2:00 PM  
Thermoplastic Elastomers for High Performance Barocaloric Cooling: Naveen Weerasekera1; Kameswara Pavan Ajjarapu1; Kavish Sudan1; Gamini Sumanasekera1; Kunal Kate1; Bikram Bhatia1; 1University of Louisville
    Solid state refrigeration (SSR) represents a promising alternative to vapor compression refrigeration systems which have a high global warming potential. In comparison to other SSR technologies, systems based on the barocaloric effect – temperature/entropy change in response to hydrostatic pressure – remain relatively unexplored. Soft materials are attractive candidate materials for SSR due to their low cost, high compressibility and large barocaloric response. In this work we investigate the barocaloric performance of commercially available block copolymer thermoplastic elastomers. We experimentally characterize the mechanical, thermal and barocaloric properties of these materials, and evaluate their potential for SSR. We measured a normalized refrigeration capacity as high as 42 kJ K-1 GPa-1 for a 65℃ temperature span at relatively low pressures (<100 MPa), and a quasi-adiabatic temperature change of 28 oC (applied pressure: 434 MPa). These results demonstrate the superior barocaloric properties of thermoplastic elastomers and their promise for next generation SSR devices.

2:20 PM  Invited
Caloric Materials for New Heat-management Technologies: Dejvid Črešnar1; Matic Morgan1; Boštjan Zalar1; Samo Kralj2; Zdravko Kutnjak1; Gregor Skačej3; Brigita Rozic1; 1Jozef Stefan Institute; 2University of Maribor; 3University of Ljubljana
    With increased environmental awareness, the search for an environmentally friendlier heat- management device has been the topic of many scientific studies. Materials with large caloric effects, such as the electrocaloric (EC) and elastocaloric (eC) effects, have the promise of realizing new solid-state refrigeration techniques. A review of recent direct measurements of the large EC effect in liquid crystals (LCs) and large eC effect in liquid crystal elastomers (LCEs) will be given in this contribution [1], including the application aspect. In particular, in smectic LCs and mixtures of LCs with functionalized nanoparticles, the EC effect exceeds 8 K and the eC in main-chain (MC) LCEs [2] exceeds 1K. However, both soft materials can play a significant role as active cooling elements and parts of thermal diodes or regeneration material in developing new cooling devices.[1] D. Črešnar et al, Liq. Cryst. 48:405-411, 2021. [2] A. Rešetič et al, Nat Comm 7:13140,2016.

2:50 PM  Invited
Electronic Structure Calculations of Materials Converting Energy: Thermoelectrics and Ion Batteries: Janusz Tobola1; Michal Rybski1; Kamil Kutorasinski1; Janina Molenda1; 1AGH University of Science and Technology
     The efficiency of materials converting various forms of energy due to thermoelectric or electrochemical effects is related to peculiar electronic properties driving transport and electrochemical behaviors. The Korringa-Kohn-Rostoker method with coherent potential approximation (KKR-CPA) is implemented for electronic structure calculations to account for disorder in thermoelectric and ion-battery systems. The results on KKR-CPA computations combined with modeling of electron transport (Boltzmann approach) and electrochemical (electromotive force) properties in selected thermoelectric [1] and Li-/Na-ion battery [2,3] materials are presented. Noteworthy, unusual electronic structure features appearing in thermoelectric (band convergence, spin-orbit coupling) and ion-battery (step-like vs. continuous-like character of discharge curves), evidently determine their performance. KKR-CPA method is used to study the high-entropy oxides for Na-ion cathode [3]. [1] B. Wiendlocha et al., Scripta Mater. 111 (2016) 33. [2] J. Molenda et al., Phys. Stat. Sol. A 217 (2020) 1900951.[3] K. Walczak et al., Energy Storage Mater. 47 (2022) 500.

3:20 PM Break

3:40 PM  
The Development of a Machine Learning Guided Process for the Additive Manufacturing of Thermoelectric Materials: Connor Headley1; Roberto Herrera del Valle1; Ji Ma1; Prasanna Balachandran1; Vijayabarathi Ponnambalam2; Saniya LeBlanc2; Dylan Kirsch3; Joshua Martin3; 1University of Virginia; 2George Washington University; 3National Institute of Standards and Technology
    The implementation of additive manufacturing promises to create thermoelectric devices with increased efficiency and lowered production costs. However, the optimal additive manufacturing processing parameters for any thermoelectric material are currently unknown, and the development of an additive manufacturing process for a new material is traditionally an arduous task that requires numerous rounds of experimental trial-and-error. Through the integration of machine learning techniques alongside well-curated additive manufacturing experimentation, we quickly draw vital connections between processing parameters, melt pool geometries, and defects while significantly reducing experimental burden. We rapidly developed process parameters for laser powder bed fusion that created highly dense, geometrically complex bismuth telluride parts through additive manufacturing. A system of high throughput sample fabrication and characterization was devised to determine the relationship between processing conditions and resulting thermoelectric properties. These connections have allowed us to intentionally vary the character of these samples from n-type to p-type through processing parameter modifications.

4:00 PM  
Thermoelectric Properties of Additively Manufactured Fe3Al2Si3: Babak Alinejad1; Amir Mostafaei1; 1Illinois Institute of Technology
    A unique feature of thermoelectric materials is their ability to convert heat to electricity, thus enabling them to recycle wasted energy. The nontoxicity and abundance of raw materials make the Fe3Al2Si3 intermetallic compound an attractive candidate for room-temperature thermoelectric applications. Fe3Al2Si3 powder is synthesized by mechanical activation of Si nanoparticles together with micron-size Al and Fe. Powder with a size distribution of 50-100 µm is processed in laser powder bed fusion (LPBF) machine. We establish a process map for the production of defect-free, high-density and homogeneous Fe3Al2Si3 parts. Microstructure, composition and thermoelectric properties of the LPBF process parts are evaluated. The power factor is measured to be about 700 µW/mK2 for an n-type and about 600 µW/mK2 for a p-type Fe3Al2Si3 at 373 K.

4:20 PM  
Multi-layer Numerical Modeling of Selective Laser Melting Based Additive Manufacturing of Thermoelectric Powders : Jagannath Suresh1; Lei Zuo1; 1Virginia Tech
    Thermoelectric generators convert heat energy to electricity and can be used for waste heat recovery, enabling sustainable development. Selective laser melting (SLM) based additive manufacturing process is a scalable and flexible method to manufacture high efficiency compact thermoelectric materials. Analyzing the thermo-fluid model of the SLM process for multiple layers is essential to decide the laser scanning parameters. In this work, a single-layer numerical model is developed using the volume of fluid and finite volume method to study the fluid flow, solidification, and heat transfer in the SLM melt-pool. Physical flow behaviors like the Marangoni effect, buoyant force, surface tension, and drag force are considered. The developed model provided the effects of the process parameters on the melt-pool and helped decide the precise scanning parameters for efficient fabrication.

4:40 PM  Invited
Calcium Cobaltate Based Composite Ceramics for Thermoelectric Energy Harvesting: Armin Feldhoff1; Zhijun Zhao1; Mario Wolf1; Matthias Jakob2; Oliver Oeckler2; Richard Hinterding1; 1Leibniz University Hannover; 2University of Leipzig
    The p-type Ca3Co4-xO9+δ combines a high power factor with a low thermal conductivity. To enhance the thermoelectric properties, we investigated the influence of individually adding perovskite-related oxides such as the mixed ionic-electronic conductor La2NiO4+δ or the large bandgap semiconductor Na2Ca2Nb4O13 to obtain sintered composite ceramics. All three oxides are characterized by layered structures and therefore anisotropic transport properties. To benefit from a preferred orientation in a textured green body, gained by uniaxially pressing, the added oxides were synthesized as large anisotropic plate-like crystals in the size of several microns using molten-flux synthesis. Analyses of the composite ceramics revealed the influence of the added phases on the thermoelectric properties and enabled the identification of reaction products at heteromaterial interphases. Multiphase composite ceramics with enhanced thermoelectric properties resulted. Compared to pure Ca3Co4-xO9+δ, in the temperature range of 373 to 1073 K, the average thermoelectric figure could be improved by up to 28%.