研究揭示電沉積錳氧化物中的銨離子存儲原理
作者:
小柯機器人發布時間:2020/12/19 13:55:54
東北大學Yu Song等研究人員合作揭示電沉積錳氧化物中的銨離子存儲原理。該研究於2020年12月15日在線發表於國際一流學術期刊《德國應用化學》。
研究人員首次研究了電沉積錳氧化物(MnOx)中的NH4+存儲化學。MnOx在稀乙酸銨(NH4Ac)電解質中的充電/放電過程中會經歷形變和相變。NH4Ac的濃度在MnOx內部NH4+的儲存中起著重要作用。轉換後的分層結構MnOx在0.5 A g-1的電流密度下可提供176 mAh g-1的高比容量,並且在0.5 M NH4Ac中的10000次循環中表現出良好的循環穩定性,其性能優於最先進的NH4+主體材料。
實驗結果表明,固溶行為與層狀MnOx中的NH4+遷移有關。光譜學研究和理論計算表明,可逆的NH4+嵌入/脫嵌過程伴隨著NH4+與MnOx層之間的H鍵形成/斷裂。這些發現為基於NH4+的能量存儲提供了一個新的研究原型(即MnOx分層),並有助於對金屬氧化物中NH4+的存儲機理的了解。
據介紹,NH4+離子作為電荷載體在水性可充電電池中顯示出巨大的潛力。
附:英文原文
Title: Ammonium‐Ion Storage in Electrodeposited Manganese Oxides
Author: Yu Song, Qing Pan, Huizhen Lv, Duo Yang, Zengming Qin, Ming-Yue Zhang, Xiaoqi Sun, Xiao-Xia Liu
Issue&Volume: 15 December 2020
Abstract: NH4+ ions as charge carriers show great potential in aqueous rechargeable batteries. Herein, we study for the first time the NH4+ storage chemistry in electrodeposited manganese oxide (MnOx). MnOx experiences morphology and phase transformation during charge/discharge in diluted ammonium acetate (NH 4Ac) electrolyte. The NH4Ac concentration plays an important role in NH4+ storage inside MnOx. The transformed MnOx with layered structure delivers a high specific capacity of 176 mAh g‐1 at the current density of 0.5 A g‐1 , and exhibits good cycling stability over 10000 cycles in 0.5 M NH4Ac, outperforming the state‐of‐the‐art NH4+ hosting materials. Experimental results suggest a solid‐solution behavior associated with NH4+ migration in layered MnOx. Spectroscopy studies and theoretical calculations indicate that the reversible NH4+ insertion/deinsertion is accompanied by H bond formation/breaking between NH4+ and the MnOx layers. These findings provide a new study prototype (i.e., layered MnOx) for NH4+‐based energy storage and contribute to the fundamental understanding of the NH4+ storage mechanism in metal oxides.
DOI: 10.1002/anie.202013110
Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202013110