Song Yu, Pan Qing, Lv Huizhen, Yang Duo, Qin Zengming, Zhang Ming-Yue, Sun Xiaoqi, Liu Xiao-Xia
Department of Chemistry, Northeastern University, 3-11, Wenhua Road, Heping district, Shenyang, 110819, China.
Key Laboratory of Data Analytics and Optimization for Smart Industry, Northeastern University, 3-11, Wenhua Road, Heping district, Shenyang, 110819, China.
Angew Chem Int Ed Engl. 2021 Mar 8;60(11):5718-5722. doi: 10.1002/anie.202013110. Epub 2021 Jan 28.
NH ions as charge carriers show potential for aqueous rechargeable batteries. Studied here for the first time is the NH -storage chemistry using electrodeposited manganese oxide (MnO ). MnO experiences morphology and phase transformations during charge/discharge in dilute ammonium acetate (NH Ac) electrolyte. The NH Ac concentration plays an important role in NH storage for MnO . The transformed MnO with a layered structure delivers a high specific capacity (176 mAh g ) at a current density of 0.5 A g , and exhibits good cycling stability over 10 000 cycles in 0.5 M NH Ac, outperforming the state-of-the-art NH hosting materials. Experimental results suggest a solid-solution behavior associated with NH migration in layered MnO . Spectroscopy studies and theoretical calculations show that the reversible NH insertion/deinsertion is accompanied by hydrogen-bond formation/breaking between NH and the MnO layers. These findings provide a new prototype (i.e., layered MnO ) for NH -based energy storage and contributes to the fundamental understanding of the NH -storage mechanism for metal oxides.
铵根离子作为电荷载体在水系可充电电池中展现出潜力。本文首次研究了使用电沉积氧化锰（MnO）的铵存储化学。在稀醋酸铵（NH₄Ac）电解质中充放电过程中，MnO经历了形貌和相变。NH₄Ac浓度对MnO的铵存储起着重要作用。具有层状结构的转变后的MnO在0.5 A g⁻¹的电流密度下具有高比容量（176 mAh g⁻¹），并且在0.5 M NH₄Ac中10000次循环内表现出良好的循环稳定性，优于目前最先进的铵容纳材料。实验结果表明在层状MnO中存在与铵迁移相关的固溶体行为。光谱研究和理论计算表明，可逆的铵嵌入/脱出伴随着铵与MnO层之间氢键的形成/断裂。这些发现为基于铵的能量存储提供了一种新的原型（即层状MnO），并有助于从根本上理解金属氧化物的铵存储机制。
