Synthesis, Characterization and Electrochemistry of Lithium Battery Electrodes: xLi2MnO3•(1-x)LiMn0.333Ni0.333Co0.333O2 (0 ≤ x ≤ 0.7)
Synthesis, Characterization and Electrochemistry of Lithium Battery Electrodes: xLi2MnO3•(1-x)LiMn0.333Ni0.333Co0.333O2 (0 ≤ x ≤ 0.7)
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DOI：
10.1021/cm801245r
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发表时间：
2008-10-14
影响因子：
8.6
通讯作者：
Thackeray, Michael M.
中科院分区：
文献类型：
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作者：
Johnson, Christopher S.;Li, Naichao;Thackeray, Michael M.
用通式xLi(2)MnO(3)中心点（1-x）LiMO2表示的富含锂和锰的层状电极材料是高功率和高容量锂离子电池的研究热点，其中M为Mn、Ni和Co。本文重点介绍了xLi(2)MnO(3)中心点（1-x）LiMn0.333Ni0.333Co0.333O2宽组成范围（0 200 mAh/g）电极的合成、结构和电化学表征。特别注意的是电极组成0.3 li (2)MnO(3)中心点0.7LiMn(0.333)Ni(0.333)Co(0.333)O(2) (x = 0.3)，如果在充电过程中完全衰减，生成mn0.533 ni0.233 co0.2330 o2，其中锰离子是四价的，当完全放电时，limn0.533 ni0.233 co0.2330 o2复合电极结构与0.1 M HNO3化学激活Li2MnO3成分，从本质上消除了第一次循环容量损失，但损害了电化学行为。讨论了与前期报道一致的Li2MnO3组分。电化学充放电曲线和循环伏安图数据表明，在富锰循环电极中产生的小尖晶石状区域有助于稳定电极，特别是在低锂负载（高电位）下。该研究强调，当x值较高时，相对较小的LiMO2浓度可以稳定层状Li2MnO3电极，使其在充电至高电位时可逆地插入和提取锂。
Lithium- and manganese-rich layered electrode materials, represented by the general formula xLi(2)MnO(3)center dot(1-x)LiMO2 in which M is Mn, Ni, and Co, are of interest for both high-power and high-capacity lithium ion cells. In this paper, the synthesis, structural and electrochemical characterization of xLi(2)MnO(3)center dot(1-x)LiMn0.333Ni0.333Co0.333O2 electrodes over a wide compositional range (0 200 mAh/g) electrodes are highlighted. Particular attention is given to the electrode composition 0.3Li(2)MnO(3)center dot 0.7LiMn(0.333)Ni(0.333)Co(0.333)O(2) (x = 0.3) which, if completely delithiated during charge, yields Mn0.533Ni0.233Co0.233O2, in which the manganese ions are tetravalent and, when fully discharges, LiMn0.533Ni0.233Co0.233O2 composite electrode structures with 0.1 M HNO3 chemically activates the Li2MnO3 component and essentially eliminates the first cycle capacity loss but damages electrochemical behavior, consistent with earlier reports for Li2MnO3 component are discussed. Electrochemical charge/discharge profiles and cyclic voltammogram data suggest that small spinel-like regions, generated in cycled manganese-rich electrodes, serve to stabilize the electrodes, particularly at low lithium loadings (high potentials). The study emphasizes that, for high values of x, a relatively small LiMO2 concentration stabilizes a layered Li2MnO3 electrode to reversible lithium insertion and extraction when charged to a high potential.