鋰硫電池由於其出色的能量密度以及低成本的硫(用於電池陰極部分)而被廣泛認為是下一代最有前途的儲能系統之一，同時在未來技術的發展顯示出巨大的前景，例如超長途飛行器的開發和延長水下機器人的壽命。然而，即使鋰硫電池有著亮眼的優勢，其在充放電時所產生的液態多硫化鋰在電解液中的溶解及穿梭效應使得鋰硫電池的電池表現受到不小的影響，並在實際應用方面仍面對著諸多困難。因此，減少會造成活性物質的損失並影響鋰硫電池性能的多硫化物穿梭現象是改善鋰硫電池一個必不可少的問題。為此，具有非凡吸附能力的高熵氧化物進入了科學家以及投資者們的視野。本研究利用包含了鎂、鉻、錳、鈷和鎳的高熵氧化物 (HEO)作為鋰硫電池隔離膜的添加劑，用於捕捉自陰極處所產生的多硫化物。此高熵氧化物具有單相尖晶石結構，且具有獨特的內核-外殼形態，其表面積的提升使得更多的活性位點產生，可吸附更多的多硫化物。而在此研究中高熵氧化物也被還原為高熵合金/氧化物以提高其導電性。高熵氧化物和高熵合金/氧化物在此研究中均經過材料分析，包括 X射線廣角繞射分析 (XRD)、感應藕合電漿質譜分析 (ICP)、掃描式電子顯微鏡 (SEM)、高解析穿透式電子顯微鏡 (TEM) 和化學分析電子光譜(XPS)。再來，通過紫外-可見光（UV-vis）測試進行多硫化物的吸附測試。而電化學分析的部分，分析了電化學阻抗譜 (EIS)、循環伏安法 (CV) 測量以及長循環和倍率性能測試。同時，還高熵合金/氧化物中不同合金比例之材料特性亦在此研究中被討論。

Lithium sulfur batteries are widely known as one of the most promising next generation energy storage systems because of its brilliant energy density and the low expense of Sulfur which used in the cathode part of the battery, showing great vision in the future technology as the development of aerial vehicle and the sustainability of the underwater robots. However, the dissolution and shuttling of the liquid-state lithium polysulfides make it difficult for LSB to come into practical application. Therefore, it is an essential issue to alleviate the shuttling of LiPSs that cause the loss of active material and influence the performance of the battery. To this end, high entropy oxide with extraordinary adsorption ability has come into scientists’ eyes. Herein, a high entropy oxide (HEO) MgCrMnCoNiO containing as an additive in the separator for LiPS trapping is reported. The HEO exhibits single phase spinel structure having a unique core-shell morphology. The HEO is also de-alloyed to MgCrMnCoNiO/A for enhancing the electrical conductivity. Both the HEO and HEO/A are subjected to material characterizations, including X-ray diffractometry (XRD), inductively coupled plasma (ICP), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Then, lithium polysulfide adsorption test is done by ultraviolet– visible (UV-vis) test. For electrochemical analysis, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) measurements as well as cycle and rate performance are analyzed. The effect of the alloy percentage in HEO on battery performance is also addressed and discussed.

[1] J. B. Goodenough and Y. Kim, "Challenges for Rechargeable Li Batteries." (in English), Chemistry of Materials, 22, 3, 587-603, (2010).
[2] H. Zhang, C. M. Li, G. G. Eshetu, S. Laruelle, S. Grugeon, K. Zaghib, C. Julien, A. Mauger, D. Guyomard, T. Rojo, N. Gisbert-Trejo, S. Passerini, X. J. Huang, Z. B. Zhou, P. Johansson, and M. Forsyth, "From Solid-Solution Electrodes and the Rocking-Chair Concept to Today's Batteries." (in English), Angewandte Chemie-International Edition, 59, 2, 534-538, (2020).
[3] M. Hagen, D. Hanselmann, K. Ahlbrecht, R. Maca, D. Gerber, and J. Tubke, "Lithium-Sulfur Cells: The Gap between the State-of-the-Art and the Requirements for High Energy Battery Cells." (in English), Advanced Energy Materials, 5, 16, (2015).
[4] W. C. Ren, W. Ma, S. F. Zhang, and B. T. Tang, "Recent advances in shuttle effect inhibition for lithium sulfur batteries." (in English), Energy Storage Materials, 23, 707-732, (2019).
[5] G. M. Wang, Y. Yang, D. D. Han, and Y. Li, "Oxygen defective metal oxides for energy conversion and storage." (in English), Nano Today, 13, 23-39, (2017).
[6] J. W. Yeh, S. K. Chen, S. J. Lin, J. Y. Gan, T. S. Chin, T. T. Shun, C. H. Tsau, and S. Y. Chang, "Nanostructured high-entropy alloys with multiple principal elements: Novel alloy design concepts and outcomes." (in English), Advanced Engineering Materials, 6, 5, 299-303, (2004).
[7] Y. Zhang, T. T. Zuo, Z. Tang, M. C. Gao, K. A. Dahmen, P. K. Liaw, and Z. P. Lu, "Microstructures and properties of high-entropy alloys." (in English), Progress in Materials Science, 61, 1-93, (2014).
[8] A. Sarkar, Q. S. Wang, A. Schiele, M. R. Chellali, S. S. Bhattacharya, D. Wang, T. Brezesinski, H. Hahn, L. Velasco, and B. Breitung, "High-Entropy Oxides: Fundamental Aspects and Electrochemical Properties." (in English), Advanced Materials, 31, 26, (2019).
[9] Y. J. Ma, Y. Ma, Q. S. Wang, S. Schweidler, M. Botros, T. T. Fu, H. Hahn, T. Brezesinski, and B. Breitung, "High-entropy energy materials: challenges and new opportunities." (in English), Energy & Environmental Science, 14, 5, 2883-2905, (2021).
[10] N. K. Katiyar, G. Goel, and S. Goel, "Emergence of machine learning in the development of high entropy alloy and their prospects in advanced engineering applications." (in English), Emergent Materials, 4, 6, 1635-1648, (2021).
[11] D. B. Miracle and O. N. Senkov, "A critical review of high entropy alloys and related concepts." (in English), Acta Materialia, 122, 448-511, (2017).
[12] J. W. Yeh, "Alloy Design Strategies and Future Trends in High-Entropy Alloys." (in English), Jom, 65, 12, 1759-1771, (2013).
[13] C. W. Tsai, Y. L. Chen, M. H. Tsai, J. W. Yeh, T. T. Shun, and S. K. Chen, "Deformation and annealing behaviors of high-entropy alloy Al0.5CoCrCuFeNi." (in English), Journal of Alloys and Compounds, 486, 1-2, 427-435, (2009).
[14] A. Sarkar, L. Velasco, D. Wang, Q. S. Wang, G. Talasila, L. de Biasi, C. Kubel, T. Brezesinski, S. S. Bhattacharya, H. Hahn, and B. Breitung, "High entropy oxides for reversible energy storage." (in English), Nature Communications, 9, (2018).
[15] T. X. Nguyen, J. Patra, J. K. Chang, and J. M. Ting, "High entropy spinel oxide nanoparticles for superior lithiation-delithiation performance." (in English), Journal of Materials Chemistry A, 8, 36, 18963-18973, (2020).
[16] L. J. Zhang, W. W. Cai, and N. Z. Bao, "Top-Level Design Strategy to Construct an Advanced High-Entropy Co-Cu-Fe-Mo (Oxy)Hydroxide Electrocatalyst for the Oxygen Evolution Reaction." (in English), Advanced Materials, 33, 22, (2021).
[17] T. X. Nguyen, C. C. Tsai, V. Nguyen, Y. J. Huang, Y. H. Su, S. Y. Li, R. K. Xie, Y. J. Lin, J. F. Lee, and J. M. Ting, "High entropy promoted active site in layered double hydroxide for ultra-stable oxygen evolution reaction electrocatalyst." (in English), Chemical Engineering Journal, 466, (2023).
[18] T. Jin, X. H. Sang, R. R. Unocic, R. T. Kinch, X. F. Liu, J. Hu, H. L. Liu, and S. Dai, "Mechanochemical-Assisted Synthesis of High-Entropy Metal Nitride via a Soft Urea Strategy." (in English), Advanced Materials, 30, 23, (2018).
[19] M. H. Hsieh, M. H. Tsai, W. J. Shen, and J. W. Yeh, "Structure and properties of two Al-Cr-Nb-Si-Ti high-entropy nitride coatings." (in English), Surface & Coatings Technology, 221, 118-123, (2013).
[20] L. Lin, K. Wang, A. Sarkar, C. Njel, G. Karkera, Q. S. Wang, R. Azmi, M. Fichtner, H. Hahn, S. Schweidler, and B. Breitung, "High-Entropy Sulfides as Electrode Materials for Li-Ion Batteries." (in English), Advanced Energy Materials, 12, 8, (2022).
[21] M. J. Cui, C. P. Yang, B. Y. Li, Q. Dong, M. L. Wu, S. Hwang, H. Xie, X. Z. Wang, G. F. Wang, and L. B. Hu, "High-Entropy Metal Sulfide Nanoparticles Promise High-Performance Oxygen Evolution Reaction." (in English), Advanced Energy Materials, 11, 3, (2021).
[22] C. M. Rost, E. Sachet, T. Borman, A. Moballegh, E. C. Dickey, D. Hou, J. L. Jones, S. Curtarolo, and J. P. Maria, "Entropy-stabilized oxides." (in English), Nature Communications, 6, (2015).
[23] J. Dabrowa, M. Stygar, A. Mikula, A. Knapik, K. Mroczka, W. Tejchman, M. Danielewski, and M. Martin, "Synthesis and microstructure of the (Co,Cr,Fe,Mn,Ni)(3)O-4 high entropy oxide characterized by spinel structure." (in English), Materials Letters, 216, 32-36, (2018).
[24] J. L. Braun, C. M. Rost, M. Lim, A. Giri, D. H. Olson, G. N. Kotsonis, G. Stan, D. W. Brenner, J. P. Maria, and P. E. Hopkins, "Charge-Induced Disorder Controls the Thermal Conductivity of Entropy-Stabilized Oxides." (in English), Advanced Materials, 30, 51, (2018).
[25] Y. Sharma, B. L. Musico, X. Gao, C. Y. Hua, A. F. May, A. Herklotz, A. Rastogi, D. Mandrus, J. Q. Yan, H. N. Lee, M. F. Chisholm, V. Keppens, and T. Z. Ward, "Single-crystal high entropy perovskite oxide epitaxial films." (in English), Physical Review Materials, 2, 6, (2018).
[26] R. Djenadic, A. Sarkar, O. Clemens, C. Loho, M. Botros, V. S. K. Chakravadhanula, C. Kubel, S. S. Bhattacharya, A. S. Gandhif, and H. Hahn, "Multicomponent equiatomic rare earth oxides." (in English), Materials Research Letters, 5, 2, 102-109, (2017).
[27] Y. Wang, J. X. Mi, and Z. S. Wu, "Recent status and challenging perspective of high entropy oxides for chemical catalysis." (in English), Chem Catalysis, 2, 7, 1624-1656, (2022).
[28] Y. Q. Zhang, D. D. Wang, and S. Y. Wang, "High-Entropy Alloys for Electrocatalysis: Design, Characterization, and Applications." (in English), Small, 18, 7, (2022).
[29] X. Wang, W. Guo, and Y. Z. Fu, "High-entropy alloys: emerging materials for advanced functional applications." (in English), Journal of Materials Chemistry A, 9, 2, (2021).
[30] D. B. Miracle, J. D. Miller, O. N. Senkov, C. Woodward, M. D. Uchic, and J. Tiley, "Exploration and Development of High Entropy Alloys for Structural Applications." (in English), Entropy, 16, 1, 494-525, (2014).
[31] N. K. Katiyar, K. Biswas, J. W. Yeh, S. Sharma, and C. S. Tiwary, "A perspective on the catalysis using the high entropy alloys." (in English), Nano Energy, 88, (2021).
[32] Z. Y. Ding, J. J. Bian, S. Shuang, X. D. Liu, Y. C. Hu, C. W. Sun, and Y. Yang, "High Entropy Intermetallic-Oxide Core-Shell Nanostructure as Superb Oxygen Evolution Reaction Catalyst." (in English), Advanced Sustainable Systems, 4, 5, (2020).
[33] M. Sahlberg, D. Karlsson, C. Zlotea, and U. Jansson, "Superior hydrogen storage in high entropy alloys." (in English), Scientific Reports, 6, (2016).
[34] R. Q. Yao, Y. T. Zhou, H. Shi, W. B. Wan, Q. H. Zhang, L. Gu, Y. F. Zhu, Z. Wen, X. Y. Lang, and Q. Jiang, "Nanoporous Surface High-Entropy Alloys as Highly Efficient Multisite Electrocatalysts for Nonacidic Hydrogen Evolution Reaction." (in English), Advanced Functional Materials, 31, 10, (2021).
[35] B. Talluri, M. L. Aparna, N. Sreenivasulu, S. S. Bhattacharya, and T. Thomas, "High entropy spinel metal oxide (CoCrFeMnNi)(3)O-4 nanoparticles as a high-performance supercapacitor electrode material." (in English), Journal of Energy Storage, 42, (2021).
[36] I. Hussain, C. Lamiel, M. Ahmad, Y. T. Chen, S. Shuang, M. S. Javed, Y. Yang, and K. L. Zhang, "High entropy alloys as electrode material for supercapacitors: A review." (in English), Journal of Energy Storage, 44, (2021).
[37] H. Chen, N. Qiu, B. Z. Wu, Z. M. Yang, S. Sun, and Y. Wang, "A new spinel high-entropy oxide (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)(3)O-4 with fast reaction kinetics and excellent stability as an anode material for lithium ion batteries." (in English), Rsc Advances, 10, 16, 9736-9744, (2020).
[38] J. H. Yan, D. Wang, X. Y. Zhang, J. S. Li, Q. Du, X. Y. Liu, J. R. Zhang, and X. W. Qi, "A high-entropy perovskite titanate lithium-ion battery anode." (in English), Journal of Materials Science, 55, 16, 6942-6951, (2020).
[39] Y. N. Zheng, Y. K. Yi, M. H. Fan, H. Y. Liu, X. Li, R. Zhang, M. T. Li, and Z. A. Qiao, "A high-entropy metal oxide as chemical anchor of polysulfide for lithium-sulfur batteries." (in English), Energy Storage Materials, 23, 678-683, (2019).
[40] S. H. Chung, Y. H. Wu, Y. H. Tseng, T. X. Nguyen, and J. M. Ting, "High Entropy Oxide (CrMnFeNiMg)(3) O(4) with Large Compositional Space Shows Long-Term Stability as Cathode in Lithium-Sulfur Batteries." ChemSusChem, 16, 8, e202300135, (2023).
[41] R. He, L. L. Yang, Y. Zhang, X. Wang, S. Lee, T. Zhang, L. X. Li, Z. F. Liang, J. W. Chen, J. S. Li, A. O. Moghaddam, J. Llorca, M. Ib, J. Arbiol, Y. Xu, and A. Cabot, "A CrMnFeCoNi high entropy alloy boosting oxygen evolution/reduction reactions and zinc-air battery performance." (in English), Energy Storage Materials, 58, 287-298, (2023).
[42] Z. Y. Jin, J. Lyu, Y. L. Zhao, H. L. Li, X. Lin, G. Q. Xie, X. J. Liu, J. J. Kai, and H. J. Qiu, "Rugged High-Entropy Alloy Nanowires with in Situ Formed Surface Spinel Oxide As Highly Stable Electrocatalyst in Zn-Air Batteries." (in English), Acs Materials Letters, 2, 12, 1698-1706, (2020).
[43] A. Manthiram, S. H. Chung, and C. X. Zu, "Lithium-Sulfur Batteries: Progress and Prospects." (in English), Advanced Materials, 27, 12, 1980-2006, (2015).
[44] W. Z. Cao, J. N. Zhang, and H. Li, "Batteries with high theoretical energy densities." (in English), Energy Storage Materials, 26, 46-55, (2020).
[45] X. Y. Huang, J. J. Xue, M. Xiao, S. J. Wang, Y. N. Li, S. C. Zhang, and Y. Z. Meng, "Comprehensive evaluation of safety performance and failure mechanism analysis for lithium sulfur pouch cells." (in English), Energy Storage Materials, 30, 87-97, (2020).
[46] C. Cavallo, M. Agostini, J. P. Genders, M. E. Abdelhamid, and A. Matic, "A free-standing reduced graphene oxide aerogel as supporting electrode in a fluorine-free Li2S8 catholyte Li-S battery." (in English), Journal of Power Sources, 416, 111-117, (2019).
[47] X. Liang, C. Y. Kwok, F. Lodi-Marzano, Q. Pang, M. Cuisinier, H. Huang, C. J. Hart, D. Houtarde, K. Kaup, H. Sommer, T. Brezesinski, J. Janek, and L. F. Nazar, "Tuning Transition Metal Oxide-Sulfur Interactions for Long Life Lithium Sulfur Batteries: The "Goldilocks" Principle." (in English), Advanced Energy Materials, 6, 6, (2016).
[48] Z. H. Wei, Y. Q. Ren, J. Sokolowski, X. D. Zhu, and G. Wu, "Mechanistic understanding of the role separators playing in advanced lithium-sulfur batteries." (in English), Infomat, 2, 3, 483-508, (2020).
[49] S. Z. Wang, J. X. Liao, X. F. Yang, J. N. Liang, Q. Sun, J. W. Liang, F. P. Zhao, A. Koo, F. P. Kong, Y. Yao, X. J. Gao, M. Q. Wu, S. Z. Yang, R. Y. Li, and X. L. Sun, "Designing a highly efficient polysulfide conversion catalyst with paramontroseite for high-performance and long-life lithium-sulfur batteries." (in English), Nano Energy, 57, 230-240, (2019).
[50] X. Song, G. P. Chen, S. Q. Wang, Y. P. Huang, Z. Y. Jiang, L. X. Ding, and H. H. Wang, "Self-Assembled Close-Packed MnO2 Nanoparticles Anchored on a Polyethylene Separator for Lithium-Sulfur Batteries." (in English), Acs Applied Materials & Interfaces, 10, 31, 26274-26282, (2018).
[51] G. Y. Xu, Q. B. Yan, S. T. Wang, A. Kushima, P. Bai, K. Liu, X. G. Zhang, Z. L. Tang, and J. Li, "A thin multifunctional coating on a separator improves the cyclability and safety of lithium sulfur batteries." (in English), Chemical Science, 8, 9, 6619-6625, (2017).
[52] E. Cha, M. Patel, S. Bhoyate, V. Prasad, and W. Choi, "Nanoengineering to achieve high efficiency practical lithium-sulfur batteries." (in English), Nanoscale Horizons, 5, 5, 808-831, (2020).
[53] G. Halkos and E. C. Gkampoura, "Where do we stand on the 17 Sustainable Development Goals? An overview on progress." (in English), Economic Analysis and Policy, 70, 94-122, (2021).
[54] H. F. Xu, R. M. Hu, Y. Z. Zhang, H. B. Yan, Q. Zhu, J. X. Shang, S. B. Yang, and B. Li, "Nano high-entropy alloy with strong affinity driving fast polysulfide conversion towards stable lithium sulfur batteries." (in English), Energy Storage Materials, 43, 212-220, (2021).
[55] M. L. Yue, H. Lambert, E. Pahon, R. Roche, S. Jemei, and D. Hissel, "Hydrogen energy systems: A critical review of technologies, applications, trends and challenges." (in English), Renewable & Sustainable Energy Reviews, 146, (2021).
[56] V. M. Maestre, A. Ortiz, and I. Ortiz, "Challenges and prospects of renewable hydrogen-based strategies for full decarbonization of stationary power applications." (in English), Renewable & Sustainable Energy Reviews, 152, (2021).
[57] A. Rukini, M. A. Rhamdhani, G. A. Brooks, and A. Van den Bulck, "Metals Production and Metal Oxides Reduction Using Hydrogen: A Review." (in English), Journal of Sustainable Metallurgy, 8, 1, 1-24, (2022).
[58] R. Chatterjee, S. Banerjee, S. Banerjee, and D. Ghosh, "Reduction of Nickel Oxide Powder and Pellet by Hydrogen." (in English), Transactions of the Indian Institute of Metals, 65, 3, 265-273, (2012).
[59] K. C. Sabat, R. K. Paramguru, S. Pradhan, and B. K. Mishra, "Reduction of Cobalt Oxide (Co3O4) by Low Temperature Hydrogen Plasma." (in English), Plasma Chemistry and Plasma Processing, 35, 2, 387-399, (2015).
[60] X. M. Xu, C. J. Niu, M. Y. Duan, X. P. Wang, L. Huang, J. H. Wang, L. T. Pu, W. H. Ren, C. W. Shi, J. S. Meng, B. Song, and L. Q. Mai, "Alkaline earth metal vanadates as sodium-ion battery anodes." (in English), Nature Communications, 8, (2017).
[61] X. Zhang, Y. P. Zhou, B. Luo, H. C. Zhu, W. Chu, and K. M. Huang, "Microwave-Assisted Synthesis of NiCo2O4 Double-Shelled Hollow Spheres for High-Performance Sodium Ion Batteries." (in English), Nano-Micro Letters, 10, 1, (2018).
[62] J. T. Richardson, R. M. Scates, and M. V. Twigg, "X-ray diffraction study of the hydrogen reduction of, NiO/alpha-Al2O3 steam reforming catalysts." (in English), Applied Catalysis a-General, 267, 1-2, 35-46, (2004).
[63] R. N. Pease and H. S. Taylor, "The reduction of copper oxide by hydrogen." (in English), Journal of the American Chemical Society, 43, 2179-2188, (1921).
[64] Y. P. Wei, Z. C. Zhang, C. Mei, J. Y. Tan, Z. Q. Wang, J. Li, and L. Gan, "Facet Dependence and Vacancy-Controlled Reversibility of the Spinel-to-Rocksalt Phase Transformation at Co3O4 Surfaces." (in English), Chemistry of Materials, 35, 11, 4461-4470, (2023).
[65] S. K. Shaw, A. Gangwar, A. Sharma, S. K. Alla, S. Kavita, M. Vasundhara, S. S. Meena, P. Maiti, and N. K. Prasad, "Structural and magnetic properties of nanocrystalline equi-atomic spinel high-entropy oxide (AlCoFeMnNi)(3)O-4 synthesised by microwave assisted co-precipitation technique." (in English), Journal of Alloys and Compounds, 878, (2021).
[66] P. W. Menezes, A. Indra, V. Gutkinb, and M. Driess, "Boosting electrochemical water oxidation through replacement of O-h Co sites in cobalt oxide spinel with manganese." (in English), Chemical Communications, 53, 57, 8018-8021, (2017).
[67] M. C. Biesinger, B. P. Payne, A. P. Grosvenor, L. W. M. Lau, A. R. Gerson, and R. S. Smart, "Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Cr, Mn, Fe, Co and Ni." (in English), Applied Surface Science, 257, 7, 2717-2730, (2011).
[68] G. Zhang, Z. W. Zhang, H. J. Peng, J. Q. Huang, and Q. Zhang, "A Toolbox for Lithium-Sulfur Battery Research: Methods and Protocols." (in English), Small Methods, 1, 7, (2017).
[69] J. Hacker, D. H. Nguyen, T. Rommel, Z. Zhao-Karger, N. Wagner, and K. A. Friedrich, "Operando UV/vis Spectroscopy Providing Insights into the Sulfur and Polysulfide Dissolution in Magnesium-Sulfur Batteries." (in English), Acs Energy Letters, 7, 1, 1-9, (2022).
[70] X. Liang, C. Hart, Q. Pang, A. Garsuch, T. Weiss, and L. F. Nazar, "A highly efficient polysulfide mediator for lithium-sulfur batteries." (in English), Nature Communications, 6, (2015).