Structural and electrochemical properties of Co–Mn–Mg multi-doped nickel based cathode materials LiNi0.9Co0.1−x[Mn1/2Mg1/2]xO2 for secondary lithium ion batteries
Structural and electrochemical properties of Co–Mn–Mg multi-doped nickel based cathode materials LiNi0.9Co0.1−x[Mn1/2Mg1/2]xO2 for secondary lithium ion batteries
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DOI：
10.1016/j.electacta.2012.12.071
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发表时间：
2013-02
影响因子：
6.6
通讯作者：
Qiang Liu;K. Du;Hongwei Guo;Zhongdong Peng;Yanbing Cao;Guo-rong Hu
中科院分区：
文献类型：
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作者：
Qiang Liu;K. Du;Hongwei Guo;Zhongdong Peng;Yanbing Cao;Guo-rong Hu
采用共沉淀法和固相法合成了钴、锰、镁共掺锂镍氧化物，其名义组成为LiNi0.9Co0.1−x[Mn1/2Mg1/2]xO2(x=0.00，0.02，0.04，0.06)。XPS结果表明，镍、钴、锰和镁的氧化态分别为+3、+3、+4和+2。X-射线衍射仪证实了α-NaFeO2有序岩盐结构具有R-−3‘m对称性。用Rieveld精修正法分析了Li/Ni的阳离子混合和镁离子的占位。镁离子分布在晶体中的3b-3a位之间。同时，通过对Mn-Mg的取代，大大减少了Li-Ni的阳离子混合。与LiNi0.9Co0.1O2相比，高锰镁含量的化合物具有更好的循环性能。用锰-镁取代钴能有效地抑制电池循环阻抗的增加。
Co, Mn and Mg co-doped lithium nickel oxides of the nominal composition LiNi0.9Co0.1−x[Mn1/2Mg1/2]xO2(x=0.00, 0.02, 0.04, 0.06) are synthesized by a co-precipitation technique and solid state route. XPS results reveal that the oxidation states of Ni, Co, Mn and Mg are +3, +3, +4 and +2, respectively. An ordered α-NaFeO2rock salt structure with R−3¯m symmetry has been confirmed by XRD. The cation mixing of Li/Ni and occupation of Mg ions have been analyzed by Rieveld refinement. Mg ions distribute between 3b and 3a sites in the crystal. Meanwhile a substantial reduction of cation mixing of Li–Ni has been confirmed by Mn–Mg substitution. Better cycling performance is observed in the compound with high Mn–Mg content compared with LiNi0.9Co0.1O2. Mn–Mg substitution for Co has been shown to suppress the increase of the cell impedance during cycles effectively.