富鎳三元正極材料的改性研究進展

摘要：富鎳三元正極材料具有高能量密度和低成本等優點，是一種有前途的正極材料。然而，富鎳三元正極材料存在容量衰減和熱穩定性差等問題。綜述了富鎳三元正極材料的晶體結構特性，對三元正極材料存在的問題進行概述；總結了形貌調控、結構設計、離子摻雜和表面包覆等提升正極材料電化學性能的改性方法，重點總結了氟離子摻雜和稀土元素摻雜以及不同合成方法包覆SiO₂對電化學性能的影響；對未來的發展進行了總結和展望。

關鍵詞：Li

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電池；富鎳三元正極材料；晶體結構；存在問題；改性研究

中圖分類號：TQ 131.11; TM 912 " " " " " "文獻標志碼：A

Research progress on modification of nickel-rich ternary cathode materials

XIAO Li1，SUN Lei1，XU Zixuan2，LIU Xuyan1

（1. School of Mechanical Engineering， University of Shanghai for Science and Technology， Shanghai 200093， China;

2. School of Mechanical Engineering， Changchun Guanghua University， Changchun 130033， China）

Abstract：Nickel-rich ternary cathode material is considered as a promising electrode material because of its high energy density and low cost. However， nickel-rich ternary cathode materials also have problems such as capacity attenuation and poor thermal stability. Firstly， the crystal structure characteristics of nickel rich ternary cathode materials are discussed， and the existing problems of ternary cathode materials are briefly summarized. Secondly， the modification methods to improve the electrochemical properties of cathode materials such as morphology control， structure design， doping and coating are reviewed. The effects of fluorine doping and rare-earth element doping， as well as different synthetic methods of coating silica on the electrochemical properties are summarized. Finally， the future development in this field is summarized and prospected.

Keywords： "lithium-ion battery; "nickel-rich ternary cathode materials; "crystal structure; "existing problems; research of modification

隨著能源短缺和環境污染等問題的加劇，鋰離子（Li^＋）因具有高電池容量、長循環壽命和低成本等優點已被廣泛應用。近年來，富鎳三元正極材料不斷向更高的放電比容量和能量密度發展的同時，電極材料中鎳的含量也不斷提升。由于鎳含量較高，三元正極材料出現循環性能差，熱穩定性差等問題，阻礙了其發展。為解決這些問題，研究人員從結構設計和制備方法等方面對三元正極材料開展了大量的改性研究來提高其整體的電化學性能。

1"富鎳三元正極材料的晶體特性

富鎳三元正極材料主要是指鎳鈷錳酸鋰（LiNi_xCo_yMn_1-x-yO₂， NCM）和鎳鈷鋁酸鋰（LiNi_x-Co_yAl_1-x-yO₂， NCA）兩種電極材料。富鎳三元正極材料在R3（–）m空間群中具有六方α-NaFeO₂層狀結構，與LiNiO₂的結構相同。O^2-、Li⁺和TM分別占據立方密堆積排列的6c、3a、3b位置，形成二維三角形晶格，如圖1所示^[1]。Ni²⁺、Co³⁺、Mn⁺三種過渡金屬元素在Li^＋電池的循環中發揮著協調作用?！?br>