Wiederaufladbare Aluminiumionenbatterien mit hoher Energiedichte – Fundamentales Materialdefekt-Engineering mit kontrollierten Grenzflächen
Zusammenfassung der Projektergebnisse
Rechargeable Al batteries are highly attractive because of their high energy density and crustal abundance of aluminum. However, the Al intercalation mechanisms at cathode, Al plating mechanisms at anode are still unclear and further investigations are needed. Based on our previous studies, we found the importance of cation vacancies on multivalent-ions intercalation process, enabling the ion diffusions mitigating the large diffusion barrier. In this study, we have focused on the role of cation vacancies in titanium oxides with lepidocrocite-type structure for trivalent Al-ion batteries. They were chosen as the representative of the compounds possessing the large quantities of vacancies stabilized by water molecules and hydroxyl-anions. The compounds were synthesized by solvothermal synthesis using an autoclave. In order to tune their crystal structures, Zn2+, Cd2+, NH4+ cations were incorporated in the lepidocrocite-type structure. The detailed structures were studied using multiple advanced techniques including X-ray diffraction and PDF analysis. The electrochemical behavior of Al3+-ions in the defect structure was further studied. While pure TiO2 is inactive for Al-ions intercalations, the lepidocrocites type structure showed the reversible capacities of ca. 160 mA h g-1. The reversible capacities were further improved with the incorporation of cations such as Zn2+, Cd2+, NH4+, reaching ca. 250 mA h g-1 with Cd2+. The capacity was maximized with the substitution amount of 0.1 per Ti and tends to lower capacities. Physicochemical characterizations indicate the cation vacancies are favorable for Al intercalations. Further Al-ions intercalation sites and structural changes were studied by X-ray total scattering with PDF analysis combined with Al NMR. Upon Al3+ insertion, further distortion of the structure were observed, and Al3+ attracts anions to form more regular anion-anon distances. Upon cycling, the initial atomic arrangement is not recovered showing that the disorder induced by the insertion of Al3+ ions is irreversible, causing capacity degradation. Theoretical study based on DFT calculations indicates most stable configuration was associated with a 6-fold coordinated Al3+ ion, which also agrees with 27Al NMR data, i.e., 6-fold coordinated Al3+ is the dominant species. Additionally, we have studied Sn(Oct)2 additives for anode-free Li batteries chemistry, enabling highly reversible Li plating-stripping without any complicated preparation process. Those studies will be extended to the improvement of Al metal anodes in the ionic liquids as well as anode-free Al batteries. The metal oxides developed for these studies showed excellent performance for electrolyzer and/or fuel cells. Iridium single atoms incorporated Co3O4 showed superior performance in oxygen evolution reaction in acidic conditions, and lithium-rich manganese oxides showed superior performance for anion exchange 1 membrane fuel cells and water electrolyzers. Those studies indicate that Al-ions intercalation is much more complicated than Li-ions, and have a large impact on the oxides framework. By tuning the anionic environment and cationic defects, the metal oxides that have suitable structure for Al-ions intercalation will be developed in the future.
Projektbezogene Publikationen (Auswahl)
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Iridium single atoms incorporated in Co3O4 efficiently catalyze the oxygen evolution in acidic conditions. Nature Communications, 13(1).
Zhu, Yiming; Wang, Jiaao; Koketsu, Toshinari; Kroschel, Matthias; Chen, Jin-Ming; Hsu, Su-Yang; Henkelman, Graeme; Hu, Zhiwei; Strasser, Peter & Ma, Jiwei
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In situ p-block protective layer plating in carbonate-based electrolytes enables stable cell cycling in anode-free lithium batteries. Nature Materials, 23(12), 1686-1694.
Shi, Jie; Koketsu, Toshinari; Zhu, Zhenglu; Yang, Menghao; Sui, Lijun; Liu, Jie; Tang, Mingxue; Deng, Zhe; Liao, Mengyi; Xiang, Jingwei; Shen, Yue; Qie, Long; Huang, Yunhui; Strasser, Peter & Ma, Jiwei
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Stabilization of layered lithium-rich manganese oxide for anion exchange membrane fuel cells and water electrolysers. Nature Catalysis, 7(5), 546-559.
Zhong, Xuepeng; Sui, Lijun; Yang, Menghao; Koketsu, Toshinari; Klingenhof, Malte; Selve, Sören; Reeves, Kyle G.; Ge, Chuangxin; Zhuang, Lin; Kan, Wang Hay; Avdeev, Maxim; Shu, Miao; Alonso-Vante, Nicolas; Chen, Jin-Ming; Haw, Shu-Chih; Pao, Chih-Wen; Chang, Yu-Chung; Huang, Yunhui; Hu, Zhiwei ... & Ma, Jiwei
