ORALS

SESSION: AdvancedMaterialsTuePM2-R10	6th Intl. Symp. on New & Advanced Materials & Technologies for Energy, Environment, Health & Sustainable Development
Tue. 29 Nov. 2022 / Room: Saitong
Session Chairs: Inmaculada Ortiz; Session Monitor: TBA

16:45: [AdvancedMaterialsTuePM211] OS
A promising alternative for oxygen production – application of air-operating <i>R</i>MnO_3+δ oxides in low-temperature TSA
Kacper Cichy¹ ; Konrad Swierczek² ; Juliusz Dąbrowa³ ; ¹AGH University of Science and Technology, Krakow, Poland; ²AGH University of Science and Technology, Faculty of Energy and Fuels, Krakow, Poland; ³AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Kraków, Poland;
Paper Id: 205 [Abstract]

The oxygen demand for medical and industrial needs grows over 6% annually from 2015, and it is estimated that the oxygen market will grow from $27.7 billion in 2019 to even $ 36.5 billion in 2030 [1]. According to The Business Research Company, this growth will be also driven by COVID-19 and the medical needs it imposes [1].<br /> Today, most of the oxygen produced for large-scale industry needs is obtained by cryogenic distillation, which due to the high energy consumption of the liquefaction of gases from the air, is an expensive method [2]. A promising alternative to the cryogenic oxygen production technology is air separation by temperature-swing adsorption (TSA) where so-called oxygen storage materials (OSM) are used. OSMs can reversibly exchange a significant amount of oxygen between their structure and atmosphere.<br /> In the last 2 decades, renewed interest in <i>R</i>MnO_3+δ oxides appeared, in terms of their application as OSMs. Their main advantage (contrary to other groups of OSMs, [3]) is the ability to work in the temperature-swing mode at temperatures as low as 200-300 °C, which is promising from both, economical and construction points of view. However, until now most of those materials operated effectively only in pure O₂ atmosphere, which is not applicable for oxygen production.<br /> A significant breakthrough has come with the results of the recent research, as it was possible to design <i>R</i>MnO_3+δ materials able to operate in air practically as effectively as in O₂ atmosphere [4]. Also, some general rules were established in terms of designing such air-operating OSMs, like dependence of oxygen storage capacity (OSC) on ionic radius of R.<br /> Nd-substituted Y_1-xNd_xMnO_3+δ materials described in this work were synthesized via sol-gel auto-combustion method followed by several variations of annealing at elevated temperatures in different atmospheres. Crystal structure and phase composition of prepared powders were examined by means of X-ray diffractometry (XRD). Oxygen storage performance was evaluated using thermogravimetry. Structure and composition of oxidized samples were also investigated by XRD. Morphology of powders was examined by scanning electron microscopy.<br /> It was established that proper modification of the preparation route of the Nd-substituted Y_1-xNd_xMnO_3+δ can increase the OSC more than twice and greatly improve the rate of redox reactions. The laboratory-scale apparatus for oxygen separation from air via TSA was designed and constructed. Equipment was tested using the YMnO3+δ-based materials developed in this work.

References:
[1] The Business Research Company, Oxygen Global Market Opportunities And Strategies (2020)\n[2] O. Parkkima, YBaCo4O_7+δ and YMnO_3+δ Based Oxygen-Storage Materials, PhD Thesis, Aalto University, Aalto, Finland, 2014\n[3] T. Motohashi, Y. Hirano, Y. Masubuchi, K. Oshima, T. Setoyama, S. Kikkawa, Chem. Mater. 25 (2013) 372-377\n[4] K. Cichy, K. Świerczek, K. Jarosz, A. Klimkowicz, M. Marzec, M. Gajewska, B. Dabrowski, Acta Mater. 205 (2021) 116544

SESSION: AdvancedMaterialsTuePM3-R10	6th Intl. Symp. on New & Advanced Materials & Technologies for Energy, Environment, Health & Sustainable Development
Tue. 29 Nov. 2022 / Room: Saitong
Session Chairs: Keyun Li; Session Monitor: TBA

17:50: [AdvancedMaterialsTuePM313] OS
Evaluation of high-entropy oxides as candidate anode materials for Li-ion cells
Maciej Moździerz¹ ; Juliusz Dąbrowa² ; Konrad Swierczek³ ; ¹AGH University of Science and Technology, Faculty of Energy and Fuels, Kraków, Poland; ²AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Kraków, Poland; ³AGH University of Science and Technology, Faculty of Energy and Fuels, Krakow, Poland;
Paper Id: 188 [Abstract]

Nowadays, Li-ion batteries are dominating electrical energy storage systems for portable electronics, and become widespread in the fast developing electric vehicles market. Their further development is also essential for the so-called large-scale energy storage, enabling effective balancing of power grid. Consequently, there is a growing worldwide demand for the next generation of Li-ion cells, having higher energy density, higher power, improved safety, and extended lifespan. Up to date, many novel alternative materials have been proposed as substitution for those currently used in the commercial Li-ion cells, which are usually based on lithium metal oxide cathodes and graphite anodes [1,2]. Among new candidate anode materials, those working on a basis of different reaction mechanisms with lithium have been proposed, including conversion-type and alloying-type reactivity, as compared with intercalation-based electrochemical reaction occurring for commonly used graphite. While high capacity could be obtained for various studied compositions, there are still many unresolved issues, with the main one including fast capacity fading during charge-discharge cycles [2]. Most recently it has been found that application of the novel group of compounds, the multi-component high-entropy oxides, allows significantly improving stability during cycling, which is thanks to synergistic effects [3]. In the literature there is an ongoing debate about electrochemical mechanisms occurring for the high-entropy electrodes, which have not been fully understood yet [3,4,5]. This work is focused on the exploration of the high-entropy oxides as anode materials in Li-ion cells. The presented studies were aimed on finding the correlation between chemical composition, crystal structure and electrochemical performance. Different, at least five-component oxides from Li-Co-Cu-Cr-Fe-Mn-Ni-Mg-Sn-Zn-O system were successfully synthesized, with their crystal structure characterized through X-ray diffraction method, to be cubic Fm-3m for MO, and Fd-3m for M₃O₄ materials, respectively. Homogeneity of the compounds was confirmed with scanning electron microscopy, combined with elemental analysis. In order to test electrochemical performance in Li-ion batteries, galvanostatic charge/discharge, cyclic voltammetry and impedance spectroscopy techniques were used. Interesting results, with high and reversible capacity observed for both groups of the studied high-entropy oxides were obtained. For example, for (Co,Cr,Fe,Mn,Ni)₃O₄-based anode discharge capacity exceeding 400 mAhg^-1 was measured in the first 20 cycles. Based on operando structural investigations, the respective models of the electrochemical reactions could be postulated. The performed studies proved applicability of the high-entropy approach to design novel Li-ion anode materials having improved electrochemical characteristics.

References:
[1] S. Chu et al., Nat. Mater., vol. 16, no. 1, pp. 16–22, 2016.
[2] K. Cao et al., Mater. Chem. Front., vol. 1, no. 11, pp. 2213–2242, 2017.
[3] A. Sarkar et al., Nat. Commun., vol. 9, no. 1, 2018.
[4] P. Ghigna et al., ACS Appl. Mater. Interfaces (2020), https://doi.org/10.1021/acsami.0c13161.
[5] T.-Y. Chen et al., J. Mater. Chem. A. 8 (2020) 21756–21770.