Unlocking Four‐electron Conversion in Tellurium Cathodes for Advanced Magnesium‐based Dual‐ion Batteries

作者：Ahiud Morag, Xingyuan Chu, Maciej Marczewski, Jonas Kunigkeit, Christof Neumann, Davood Sabaghi, Grażyna Z. Żukowska, Jingwei Du, Xiaodong Li, Andrey Turchanin, Eike Brunner, Xinliang Feng, Minghao Yu · 发表于：Angewandte Chemie International Edition · 年份：2024 · DOI：10.1002/anie.202401818 · 被引用次数：31 · 研究领域：Layered Double Hydroxides Synthesis and Applications、Advancements in Battery Materials、Inorganic Chemistry and Materials

Abstract Magnesium (Mg) batteries hold promise as a large‐scale energy storage solution, but their progress has been hindered by the lack of high‐performance cathodes. Here, we address this challenge by unlocking the reversible four‐electron Te 0 /Te 4+ conversion in elemental Te, enabling the demonstration of superior Mg//Te dual‐ion batteries. Specifically, the classic magnesium aluminum chloride complex (MACC) electrolyte is tailored by introducing Mg bis(trifluoromethanesulfonyl)imide (Mg(TFSI) 2 ), which initiates the Te 0 /Te 4+ conversion with two distinct charge‐storage steps. Te cathode undergoes Te/TeCl 4 conversion involving Cl − as charge carriers, during which a tellurium subchloride phase is presented as an intermediate. Significantly, the Te cathode achieves a high specific capacity of 543 mAh g Te −1 and an outstanding energy density of 850 Wh kg Te −1 , outperforming most of the previously reported cathodes. Our electrolyte analysis indicates that the addition of Mg(TFSI) 2 reduces the overall ion‐molecule interaction and mitigates the strength of ion‐solvent aggregation within the MACC electrolyte, which implies the facilized Cl − dissociation from the electrolyte. Besides, Mg(TFSI) 2 is verified as an essential buffer to mitigate the corrosion and passivation of Mg anodes caused by the consumption of the electrolyte MgCl 2 in Mg//Te dual‐ion cells. These findings provide crucial insights into the development of advanced Mg‐based dual‐ion batteries.