Enhanced oxygen reducibility of 0.5Li2MnO3·0.5LiNi1/3Co1/3Mn1/3O2 cathode material with mild acid treatment
Enhanced oxygen reducibility of 0.5Li2MnO3·0.5LiNi1/3Co1/3Mn1/3O2 cathode material with mild acid treatment
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DOI：
10.1016/j.jpowsour.2013.10.002
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发表时间：
2014-02
影响因子：
9.2
通讯作者：
Guofeng Xu;Jianling Li;Qingrui Xue;Xianping Ren;Gang Yan;Xindong Wang;F. Kang
中科院分区：
文献类型：
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作者：
Guofeng Xu;Jianling Li;Qingrui Xue;Xianping Ren;Gang Yan;Xindong Wang;F. Kang
采用共沉淀法合成了固溶体正极材料0.5Li2MnO3·0.5LiNi1/3Co 1/3 Mn 1/3 O2，并采用弱酸引发H+/Li+交换反应。电感耦合等离子体原子发射光谱（ICP-AES）和原子吸收光谱（AAS）数据表明，材料经处理后确实发生了H+/Li+交换反应，化学组成为H0.06Li1.15Ni0.13Co0.14Mn0.55O2.03。X射线粉末衍射分析表明，H+/Li+交换反应没有改变产物的结构，仍为六方α-NaFeO 2层状结构，空间群为R-3 m。场发射扫描电子显微镜（SEM）和透射电子显微镜（TEM）的图像显示，在H+/Li+交换的样品的表面上有侵蚀的痕迹。在0.05C（12.5 mA g−1）下测量的初始充放电曲线表明，H+/Li+交换电极提供高达314.0 mAh g− 1的容量和库仑增加的初始效率。循环伏安法（CV）的测量证实，这是由于在初始充电过程中释放的氧的还原催化活性的改善。经处理的电极还显示出改善的速率性能。
Solid solution cathode material 0.5Li2MnO3·0.5LiNi1/3Co1/3Mn1/3O2has been synthesized by a co-precipitation method and a mild acid was adopted to give rise to the H+/Li+exchange reaction. The inductively coupled plasma-atomic emission spectrometry (ICP-AES) and atomic absorption spectroscopy (AAS) data show that the H+/Li+exchange reaction actually occurs and the chemical composition is H0.06Li1.15Ni0.13Co0.14Mn0.55O2.03after the material was treated. The X-ray powder diffraction patterns indicates that the structure doesn't change through the H+/Li+exchange reaction and remains the hexagonal α-NaFeO2layered structure with space group of R-3m. The field-emission scanning electron microscope (SEM) and transmission electron microscope (TEM) images show that there are traces of erosion on the surface of the H+/Li+exchanged sample. The initial charge–discharge curve measured at 0.05C (12.5 mA g−1) demonstrates that the H+/Li+exchanged electrode delivers a capacity of up to 314.0 mAh g−1and coulombic increased initial efficiency. Cycle voltammetry (CV) measurement confirms this is attributed to the improvement of the reduction catalytic activity of oxygen released during the initial charging. The processed electrode also displays improved rate performance.