Layered buserite Mg-Mn oxide cathode for aqueous rechargeable Mg-ion battery

Owing to the features (high safety, inexpensive and environmental friendliness) of aqueous rechargeable Mg-ion batteries (ARMIBs), they have drawn extensive attention in the future energy storage systems. However, the poor Mg 2 + migration kinetics during the Mg 2 + intercalation/extraction still hinders the progress of developing suitable cathode materials. Herein, a layered buserite Mg-Mn oxide (MMO) material with large interlayer space ( similar to 9.70 a) and low-crystalline structure is studied as a high-performance cathode in ARMIBs. Compared with the counterpart, the Mg 2 + migration kinetics of the MMO cathode can be enhanced by its unique structure (bigger interlayer spacing and low-crystalline structure). The layered buserite MMO as a high-performance ARMIBs cathode exhibits high Mg storage capacity (50 mA g -1 : 169.3 mAh g -1 ), excellent rate capability (1000 mA g -1 : 98.3 mAh g -1 ), and fast Mg 2 + migration (an average diffusion coefficient: similar to 4.21 x 10 -10 cm 2 s -1 ) in 0.5 M MgCl 2 aqueous electrolyte. Moreover, the MMO-1//AC full battery achieved a high discharge capacity (100 mA g -1 : 111 mAh g -1 ), and an ignored fading over 5000 cycles (1000 mA g -1 ). Therefore, layered Mg-Mn oxide with large interlayer space may break a new path to develop the promising ARMIBs. (c) 2023 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) Peer review under responsibility of Chongqing University