【摘要】 本文提出了一种基于奥斯特瓦尔德熟化制备具有富钴表面的高镍正极材料的方法.采用了商业化的Ni_0.8Co_0.1Mn_0.1（OH）₂和喷雾热解制备了多孔Co₃O₄作为前驱体.在高温固相反应锂化过程中,多孔的Co₃O₄会分解成颗粒.根据奥斯特瓦尔德熟化过程,这些颗粒与锂盐反应并自发地沉积于高镍材料的表面,形成具有富钴表层的高镍正极材料.作为锂离子电池正极材料时,改性后的材料中阳离子的混排得到抑制,H2到H3的相变程度降低,并减少了电解液和高镍正极材料之间的副反应.因此,具有富钴表层的高镍正极材料相比于原始材料循环和倍率性能得到很大提升.NCM-Co-1(Ni_0.8Co_0.1Mn_0.1（OH）₂/Co₃O₄的摩尔比为60:1)在1 C下循环200次放电容量仍有159.2 mA h g^-1,容量保持率为90.5%.本工作为制备梯度正极材料以及解决高镍正极材料的表面问题提供了一种通用而有效的方法.更多还原

【Abstract】 An Ostwald ripening-based route is proposed to prepare Ni-rich layered cathodes with Co-rich surface for lithium-ion batteries（LIBs）. Commercially available Ni_0.8Co_0.1Mn_0.1（OH）₂ and spray pyrolysis derived porous Co₃O₄ are used as mixed precursors. During the lithiation reaction process under high-temperature, the porous Co₃O₄ microspheres scatter primary particles and spontaneously redeposit on the surface of Ni-rich spheres according to Ostwald ripening mechanism, forming the Ni-rich materials with Co-rich outer layers. When evaluated as cathode for LIBs, the resultant material shows ability to inhibit the cation disorder, relieves the phase transition from H2 to H3 and diminishes side reactions between the electrolyte and Ni-rich cathode material.As a result, the obtained material with Co-rich outer layers exhibits much more improved cycle and rate performance than the material without Co-rich outer layers. Particularly,NCM-Co-1(molar ratio of Ni_0.8Co_0.1Mn_0.1（OH）₂/Co₃O₄ is 60:1)delivers a reversible capacity of 159.2 mA h g^-1 with 90.5%capacity retention after 200 cycles at 1 C. This strategy provides a general and efficient way to produce gradient substances and to address the surface problems of Ni-rich cathode materials.更多还原