High‐voltage aqueous Mg‐ion batteries enabled by solvation structure reorganization

Abstract: Herein, an eco-friendly and high safety aqueous Mg-ion electrolyte (AME) with a wide electrochemical stability window (ESW) ≈3.7 V, containing polyethylene glycol (PEG) and low-concentration salt (0.8 m Mg(TFSI)2), is proposed by solvation structure reorganization of AME. The PEG agent significantly alters the Mg2+ solvation and hydrogen bonds network of AMEs and forms the direct coordination of Mg2+ and TFSI-, thus enhancing the physicochemical and electrochemical properties of electrolytes. As an exemplary material, V2O5 nanowires are tested in this new AME and exhibit initial high discharge/charge capacity of 359/326 mAh g-1 and high capacity retention of 80% after 100 cycles. The high crystalline α-V2O5 shows two 2-phase transition processes with the formation of ε-Mg0.6V2O5 and Mg-rich MgxV2O5 (x ≈1.0) during the first discharge. Mg-rich MgxV2O5 (x ≈1.0) phase formed through electrochemical Mg-ion intercalation at room temperature is for the first time observed via XRD. Meanwhile, the cathode electrolyte interphase (CEI) in aqueous Mg-ion batteries is revealed for the first time. MgF2 originating from the decomposition of TFSI- is identified as the dominant component. This work offers a new approach for designing high-safety, low-cost, eco-friendly, and large ESW electrolytes for practical and novel aqueous multivalent batteries

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: ISSN: 1616-3028

Classification and Topics

• Classification: Physik

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2024
• Creator: Fu, Qiang ; Wu, Xuanye ; Luo, Xianlin ; Indris, Sylvio ; Sarapulova, Angelina ; Bauer, Marina ; Wang, Zhengqi ; Knapp, Michael ; Ehrenberg, Helmut ; Wei, Yingjin ; Dsoke, Sonia

Further information

• DOI: 10.1002/adfm.202110674
• URN: urn:nbn:de:bsz:25-freidok-2438323
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 25.03.2025, 1:54 PM CET