Authors: Shiman He, Jie Wang, Xu Zhang, Jingzhao Chen, Zichun Wang, Tingting Yang, Zhiwei Liu, Yuan Liang, Boya Wang, Shiqi Liu, Liqiang Zhang, Jianyu Huang, Jun Huang, Luke A. O'Dell, Haijun Yu
Published: 2019-09-02
Source: Full article
AbstractRechargeable aluminum‐ion batteries have drawn considerable attention as a new energy storage system, but their applications are still significantly impeded by critical issues such as low energy density and the lack of excellent electrolytes. Herein, a high‐energy aluminum‐manganese battery is fabricated by using a Birnessite MnO2 cathode, which can be greatly optimized by a divalence manganese ions (Mn2+) electrolyte pre‐addition strategy. The battery exhibits a remarkable energy density of 620 Wh kg−1 (based on the Birnessite MnO2 material) and a capacity retention above 320 mAh g−1 for over 65 cycles, much superior to that with no Mn2+ pre‐addition. The electrochemical reactions of the battery are scrutinized by a series of analysis techniques, indicating that the Birnessite MnO2 pristine cathode is first reduced as Mn2+ to dissolve in the electrolyte upon discharge, and AlxMn(1−x)O2 is then generated upon charge, serving as a reversible cathode active material in following cycles. This work provides new opportunities for the development of high‐performance and low‐cost aqueous aluminum‐ion batteries for prospective applications.