无钴高镍锂离子正极材料LiNixMn1-xO2(0.5<x<1)研究进展

Research Advances of Co-free and Ni-rich LiNixMn1-xO2(0.5<x<1)Cathode Materials

锂离子电池在消费类电子产品、电动汽车、储能等领域的广泛应用,其正极材料尤其是钴酸锂、镍钴锰三元正极材料需求量也随之剧增。然而由于钴的稀缺性,钴价也随之高涨,锂离子电池正极材料开始向低钴化甚至无钴化发展。于是无钴高镍锂离子正极材料LiNix Mn1-xO2(0.5<x<1)凭借其能量密度高、镍锰资源丰富、成本低廉等优势而受到广泛关注,随着无钴高镍正极材料制备技术的进步,该体系材料产业化步伐随之加快。然而无钴高镍锂离子正极材料在寿命、放电性能方面仍存在问题,尤其是在倍率性能、高压循环稳定性、锂镍混排等方面仍需要改善。本文综述了无钴高镍锂离子正极材料LiNix Mn1-xO2(0.5<x<1)的研究进展,总结了该体系材料的成本优势、结构特征、合成方法及电化学性能。并对该体系材料在掺杂和包覆等改进方面的研究现状进行了阐述。最后对该体系材料的应用前景进行了展望,并指明了其今后的研究方向。

With the wide application of lithium-ion batteries in the fields of consumer electronics products,electric vehicles,energy storage,etc.,the demand for cathode materials,especially lithium cobalt oxide and lithium nickel-cobalt-manganese oxide cathode materials,have also increased dramatically.However,due to the scarcity of cobalt,the price of cobalt has been rising accordingly,and the cathode material of lithium-ion batteries has begun to develop toward low cobalt or even no cobalt contained.After that,LiNix Mn1-xO2(0.5<x<1),a cobalt-free and nickel-rich lithium-ion cathode material,has attracted wide attention due to its high energy density,abundant nickel-manganese resources,and low cost.With the progress of preparation technology of cobalt-free and nickel-rich cathode materials,the pace of industrialization of the materials has accelerated.Nevertheless,the cobalt-free and nickel-rich lithium-ion cathode material still has problems in terms of life and discharge performance,especially in aspects of rate performance,high voltage cycle stability,lithium-nickel mixing and other aspects which need to be improved.The research progress of LiNix Mn1-xO2(0.5<x<1),a cobalt-free and nickel-rich lithium-ion cathode material was reviewed in this paper,the cost advantages,structural characteristics,synthesis methods and electrochemical properties were summarized,the research status of the materials in the improvement of doping and coating was also described.Last but not the least,the application of the materials was prospected,and the future research directions were given.