煅烧
钴
烧结
降水
粒子(生态学)
材料科学
混合(物理)
结构精修
粒径
化学工程
化学
无机化学
结晶学
晶体结构
物理化学
冶金
催化作用
有机化学
工程类
物理
海洋学
量子力学
气象学
地质学
作者
Zhenlei Huang,Jian Gao,Xiangming He,Jianjun Li,Changyin Jiang
标识
DOI:10.1016/j.jpowsour.2011.10.143
摘要
Spherical NixCo(1−2x)Mnx(OH)2 (x = 0.333, 0.4, 0.416, 0.45) precursors with Co concentration-gradient were prepared by co-precipitation from sulfate solutions using NaOH and NH4OH as precipitation and complexing agents. Then, well-ordered spherical LiNixCo(1−2x)MnxO2 was synthesized by sintering the mixture of as-prepared precursor and Li2CO3 at 950 °C for 16 h in air. EDXS results indicated that the concentration of cobalt decreased gradually inside out of the spherical precursor particle, and it was uniform in spherical LiNixCo(1−2x)MnxO2 particle obtained by sintering with Li2CO3. According to Rietveld refinement of XRD patterns, the LiNixCo(1−2x)MnxO2 synthesized from Co gradient precursor showed lower degree of cation disorder than that prepared from conventional precursor. The well-ordered LiNixCo(1−2x)MnxO2 from Co gradient precursor delivered much better high-rate capability than conventional one. The decrease of cation disorder of LiNixCo(1−2x)MnxO2 is attributed to the cobalt-rich in core of the precursor particles. Both abundant Co3+ and Li+ can restrain cation mixing effectively. Since Li+ needs long time to reach core during calcining, cobalt-rich in core of the precursor particle is very important for restraining cation mixing. Concentration-gradient precursor is helpful to prepare well-ordered LiNixCo(1−2x)MnxO2 with good high-rate capability, and the total content of expensive and toxic cobalt does not need to be increased.
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