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人工晶体学报 ›› 2022, Vol. 51 ›› Issue (7): 1257-1269.

• 研究论文 • 上一篇    下一篇

快离子导体Li1.5Y0.5Zr1.5(PO4)3包覆层对富镍三元正极材料电化学性能的影响

罗诗健, 熊子龙, 杨凤华, 陈前林, 李翠芹   

  1. 贵州大学化学与化工学院,贵阳 550025
  • 收稿日期:2022-04-05 出版日期:2022-07-15 发布日期:2022-08-11
  • 通讯作者: 李翠芹,副教授。E-mail:licuiqin2345@163.com
  • 作者简介:罗诗健(1996—),男,江西省人,硕士研究生。E-mail:2417197038@qq.com
  • 基金资助:
    贵州省高层次人才培养计划-“百”层次人才(黔科合平台人才[2016]5658)

Effect of Fast Ionic Conductor Li1.5Y0.5Zr1.5(PO4)3 Coating Layer on the Electrochemical Performance of Ni-Rich Ternary Cathode Materials

LUO Shijian, XIONG Zilong, YANG Fenghua, CHEN Qianlin, LI Cuiqin   

  1. College of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, China
  • Received:2022-04-05 Online:2022-07-15 Published:2022-08-11

摘要: 研发富镍低钴的先进正极材料是目前提高锂离子电池能量密度和降低电池成本的有效办法。然而,随着Ni含量的增加,富镍层状氧化物普遍存在前驱体合成困难、结构不稳定和界面活性高等一系列问题,阻碍了富镍层状氧化物正极材料的市场化推广。本文采用优化的共沉淀法制备出结构稳定的LiNi0.8Mn0.1Co0.1O2(NCM811)正极材料,同时在NCM811材料表面均匀包覆快离子导体Li1.5Y0.5Zr1.5(PO4)3涂层,以克服富镍层状氧化物界面结构不稳定和易受电解液腐蚀的难题。在4.5 V高截止电压下,改性样品0.2 C的放电比容量为214.2 mAh·g-1,10 C的放电比容量高达158.8 mAh·g-1,高于原始样品的203.7 mAh·g-1(0.2 C)和82.7 mAh·g-1(10 C)。同时,改性样品在4.3 V下经1 C循环200次后的容量保持率高达84.7%,高于原始样品(61.94%)。

关键词: 锂离子电池, 共沉淀法, 快离子导体, 表面改性, 高倍率性能, 高截止电压

Abstract: The development of nickel-rich and low-cobalt cathode materials is currently an effective way to improve the energy density and reduce the cost of lithium-ion batteries. However, as Ni content increases, Ni-rich layered oxides have some problems, such as difficult precursor synthesis, structural instability, and high interfacial activity, which hinder the promotion of Ni-rich layered oxide cathode materials. In this paper, a structurally stable LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode material was prepared by an optimized co-precipitation method, while a fast ionic conductor Li1.5Y0.5Zr1.5(PO4)3 coating was uniformly wrapped on the surface of NCM811 material to overcome the difficulties of interfacial structural instability and electrolyte corrosion. At a high cut-off voltage of 4.5 V, the discharge specific capacity of the modified sample is 214.2 mAh·g-1 at 0.2 C and up to 158.8 mAh·g-1 at 10 C, which is much higher than the 203.7 mAh·g-1 (0.2 C) and 82.7 mAh·g-1 (10 C) of the original sample. Meanwhile, the capacity retention rate of the modified sample after 200 cycles of 1 C at 4.3 V is as high as 84.7%, which is higher than that of the original sample (61.94%).

Key words: lithium-ion battery, co-precipitation method, fast ionic conductor, surface modification, high rate performance, high cut-off voltage

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