Electrochemical reactions and cathode properties of Fe-doped Li2O for the hermetically sealed lithium peroxide battery
Electrochemical reactions and cathode properties of Fe-doped Li2O for the hermetically sealed lithium peroxide battery
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DOI：
10.1016/j.jpowsour.2016.04.141
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发表时间：
2016-08-01
影响因子：
9.2
通讯作者：
Mizuno, Noritaka
中科院分区：
文献类型：
--
作者：
Harada, Kosuke;Hibino, Mitsuhiro;Mizuno, Noritaka
采用机械化学法合成了Fe掺杂Li 2 O（FDL），并将其作为一种新型的无钴正极材料应用于高能量密度的密封Li 2 O2电池。Fe 3+离子被置换掺杂到反萤石型Li 2 O结构中的Li位点中以产生FDL。FDL由（Li_（0.82）Fe_（0.06））（2）O（d-FDL）和高温Li_5FeO_4（o-FDL）组成，其中Fe ~（3+）分别呈无序和有序排列。根据穆斯堡尔谱和定量过氧化物分析，FDL阴极主要基于O-2（2-）和O-2之间的氧化还原反应。X射线衍射研究表明，O-2（2-）的可逆形成主要发生在d-FDL中。当阴极被充电到超过250 mAh g（-1）时，发生涉及氧气放出的不可逆副反应。在22.5mA·g（-1）的电流密度下，FDL（Fe/（Li + Fe）= 10at%）阴极在200次循环中表现出200 mAh·g（-1）的可逆容量。(C)© 2016 Elsevier B. V.版权所有。
Fe-doped Li2O (FDL) is synthesized mechanochemically and is demonstrated as a new Co-free cathode material for use in sealed Li2O2 batteries, which have been proposed as high energy density batteries. Fe3+ ions are substitutionally doped into the Li sites in an antifluorite-type Li2O structure to create FDL. The FDL consists of (Li0.82Fe0.06)(2)O (d-FDL) and high -temperature form of Li5FeO4 (o-FDL), in which Fe3+ ions disorderly and orderly arranged, respectively. According to the Mossbauer spectra and quantitative peroxide species analysis, the FDL cathode operates principally based on the redox reaction between O-2(2-) and O2-. X-ray diffraction study reveals that the reversible formation of O-2(2-) proceeds mainly in the d-FDL. An irreversible side reaction involving the evolution of oxygen gas occurs when the cathode is charged to more than 250 mAh g(-1). The FDL (Fe/(Li + Fe) = 10 at%) cathode exhibits a reversible capacity of 200 mAh g(-1) over 200 cycles at a current density of 22.5 mA g(-1). (C) 2016 Elsevier B.V. All rights reserved.