Unravelling H+/Zn2+ Synergistic Intercalation in a Novel Phase of Manganese Oxide for High ‐Performance Aqueous Rechargeable Battery

A H+/Zn2+ synergistic intercalation mechanism for manganese oxide nanosheets is first reported and effectively enhances the electrochemical performance of an aqueous Zn battery. AbstractAqueous Zn ‐MnO2 batteries using mild electrolyte show great potential in large ‐scale energy storage (LSES) application, due to high safety and low cost. However, structure collapse of manganese oxides upon cycling caused by the conversion mechanism (e.g., from tunnel to layer structures for α‐, β‐, and γ‐phases) is one of the most urgent issues plaguing its practic al applications. Herein, to avoid the phase conversion issue and enhance battery performance, a structurally robust novel phase of manganese oxide MnO2H0.16(H2O)0.27 (MON) nanosheet with thickness of ≈2.5 nm is designed and synthesized as a promising cathode material, in which a nanosheet structure combined with a novel H+/Zn2+ synergistic intercalation mechanism is demonstrated and evidenced. Accordingly, a high ‐performance Zn/MON cell is achieved, showing a high energy density of ≈228.5 Wh kg−1, impressive cyclability with capacity retention of 96% at 0.5 C after 300 cycles, as well as exhibiting rate performance of 115.1 mAh g−1 at current rate of 10 C. To the best current knowledge, this H+/Zn2+ synergistic intercalation mechanism is first reported in an aqueous battery system, which opens a new opportunity for development of high ‐performance aqueous Zn ion batteries for LSES.

Source: Small - October 6, 2019 Category: Nanotechnology Authors: Qinghe Zhao, Xin Chen, Ziqi Wang, Luyi Yang, Runzhi Qin, Jinlong Yang, Yongli Song, Shouxiang Ding, Mouyi Weng, Weiyuan Huang, Jiajie Liu, Wenguang Zhao, Guoyu Qian, Kai Yang, Yanhui Cui, Haibiao Chen, Feng Pan Tags: Communication Source Type: research