Anion‐Incorporated Mg‐Ion Solvation Modulation Enables Fast Magnesium Storage Kinetics of Conversion‐Type Cathode Materials

• DOI: 10.1002/adma.202208289
• Publication Date: 2023-03-09T23:45:35Z
• Authors: Yinlin Shen; Yujia Wang; Yingchun Miao; Qiang Li; Xiangyu Zhao; Xiaodong Shen
• Keywords: 7. Clean energy; 3. Good health

Rechargeable magnesium batteries (RMB) have emerged as one of the most promising alternatives to lithium-ion due prominent advantages metal anodes. Nevertheless, their application is hindered by sluggish Mg-ion storage kinetics in cathodes, although various structural modifications cathode materials been performed. Herein, an electrolyte design using anion-incorporated solvation structure developed promote reactions conversion-type materials. The addition trifluoromethanesulfonate anion (OTf- ) ether-based modulates Mg2+ from [Mg(DME)3 ]2+ [Mg(DME)2.5 OTf]+ (DME = dimethoxy ethane), which facilitates desolvation and thus significantly expedites charge transfer material. As a result, as-prepared CuSe material on copper current collector exhibits considerable increase capacity 61% (228 mAh g-1 95% (357 theoretical at 0.1 A more than twofold high density 1.0 . This work provides efficient strategy via modulation achieve high-rate for RMBs. incorporation borate-based enables fast selenide achieved rate highest reversible capacities compared those previously reported cathodes.