Uniformly MXene‐Grafted Eutectic Aluminum‐Cerium Alloys as Flexible and Reversible Anode Materials for Rechargeable Aluminum‐Ion Battery

• Published in: Advanced functional materials Vol. 33; no. 1
• Main Authors: Ran, Qing, Zeng, Shu‐Pei, Zhu, Mei‐Hua, Wan, Wu‐Bin, Meng, Huan, Shi, Hang, Wen, Zi, Lang, Xing‐You, Jiang, Qing
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.01.2023
• Subjects: alloy anodes; Aluminum; aluminum‐ion batteries; Anodes; aqueous rechargeable batteries; Cerium base alloys; Dendritic structure; Electrochemical analysis; Electrode materials; Electrode polarization; Electrolytes; Energy storage; eutectic alloys; Lamella; Low voltage; Materials science; MXenes; Plating; Rechargeable batteries; Solid electrolytes; Storage batteries
• DOI: 10.1002/adfm.202211271
• ISSN: 1616-301X

Aluminum is an attractive anode material in aqueous multivalent‐metal batteries for large‐scale energy storage because of its high Earth abundance, low cost, high theoretic capacity, and safety. However, state‐of‐the‐art aqueous aluminum‐ion batteries based on aluminum anode persistently suffer from poor rechargeability and low coulombic efficiency due to irreversibility of aluminum stripping/plating and dendrite growth. Here eutectic aluminum‐cerium alloys in situ grafted with uniform ultrathin MXene (MXene/E‐Al97Ce3) as flexible, reversible, and dendrite‐free anode materials for rechargeable aqueous aluminum‐ion batteries is reported. As a result of the MXene serving as stable solid electrolyte interphase to inhibit side reactions and the lamella‐nanostructured E‐Al97Ce3 enabling directional Al stripping and deposition by making use of symbiotic α‐Al metal and intermetallic Al11Ce3 lamellas, the MXene/E‐Al97Ce3 hybrid electrodes exhibit reversible and dendrite‐free Al stripping/plating with low voltage polarization of ± 54 mV for ≥1000 h in a low‐oxygen‐concentration aqueous aluminum trifluoromethanesulfonate (Al(OTF)3) electrolyte. These superior electrochemical properties endow soft‐package aluminum‐ion batteries assembled with MXene/E‐Al97Ce3 anode and AlxMnO2 cathode to have high initial discharge capacity of ≈360 mAh g−1 at 1 A g−1, and retain ≈85% after 500 cycles, along with the coulombic efficiency of as high as 99.5%. Flexible MXene/E‐Al97Ce3 hybrid electrode that is developed by facile and scalable metallurgy and surface processing technologies exhibits exceptionally reversible, stable, and dendrite‐free Al stripping/plating behaviors in aqueous aluminum trifluoromethanesulfonate electrolyte with ultralow oxygen concentration. When coupled with the AlxMnO2‐based cathode, this electrode significantly improves rechargeability and stability of its soft‐package aluminum‐ion battery for potential use in large‐scale energy storage.