物理化学学报 >> 2022, Vol. 38 >> Issue (5): 2007017.doi: 10.3866/PKU.WHXB202007017

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高镍正极材料中钴元素的替代方案及其合成工艺优化

吴锋1,2, 李晴1,2,3, 陈来1,2,*(), 王紫润1, 陈刚1,2, 包丽颖1, 卢赟1,2, 陈实1, 苏岳锋1,2,*()   

  1. 1 北京理工大学材料学院，环境科学与工程北京市重点实验室，北京 100081
    2 北京理工大学重庆创新中心，重庆 401120
    3 劳伦斯伯克利国家实验室能量存储与分布式资源部门，美国 加州 94720
  • 收稿日期:2020-07-06 录用日期:2020-08-18 发布日期:2020-08-24
  • 通讯作者: 陈来,苏岳锋 E-mail:chenlai144@sina.com;suyuefeng@bit.edu.cn
  • 作者简介:第一联系人：

    † These authors contribute equally to this work.

  • 基金资助:
    国家重点研发项目(2016YFB0100301);国家自然科学基金(21875022);国家自然科学基金(51802020);国家自然科学基金(U1664255);北京理工大学重庆创新中心科技创新计划项目(2020CX5100006);北京理工大学"青年教师学术启动计划"项目和中国科学技术协会青年人才托举计划(2018QNRC001)

An Optimized Synthetic Process for the Substitution of Cobalt in Nickel-Rich Cathode Materials

Feng Wu1,2, Qing Li1,2,3, Lai Chen1,2,*(), Zirun Wang1, Gang Chen1,2, Liying Bao1, Yun Lu1,2, Shi Chen1, Yuefeng Su1,2,*()   

  1. 1 School of Materials Science and Engineering, Beijing Key Laboratory of Environmental Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
    2 Beijing Institute of Technology Chongqing Innovation Center, Chongqing 401120, China
    3 Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
  • Received:2020-07-06 Accepted:2020-08-18 Published:2020-08-24
  • Contact: Lai Chen,Yuefeng Su E-mail:chenlai144@sina.com;suyuefeng@bit.edu.cn
  • About author:Email: suyuefeng@bit.edu.cn (Y.S.)
    Email: chenlai144@sina.com (L.C.)
  • Supported by:
    the National Key R & D Program of China(2016YFB0100301);the National Natural Science Foundation of China(21875022);the National Natural Science Foundation of China(51802020);the National Natural Science Foundation of China(U1664255);the Science and Technology Innovation Foundation of Beijing Institute of Technology Chongqing Innovation Center(2020CX5100006);the Beijing Institute of Technology Research Fund Program for Young Scholars, and the Young Elite Scientists Sponsorship Program by CAST(2018QNRC001)

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摘要：

高镍三元正极材料LiNixMnyCo1-x-yO2 (x > 0.8)因其高能量密度而备受瞩目。在高镍三元正极材料中，Co不但有助于增强层状正极材料结构稳定性，而且能够提高正极材料导电性能，因此被认为是一种非常重要的元素。但是由于目前全球范围内钴矿资源紧缺，在一定程度上限制了含钴正极材料在新能源电动汽车领域的发展应用。基于此，本文将不同的过渡金属离子掺杂到高镍层状材料中形成无钴化正极材料，并进行高镍正极材料无钴化的可行性分析。通过实验对比发现，资源存储量丰富并且价格低廉的Zr在一定程度上可以取代Co元素，得到的正极材料LiNi0.85Mn0.1Zr0.05O2表现出良好的电化学性能，在0.2C倍率以及2.75–4.3 V的截止电压范围内，其放电比容量为179.9 mAh·g-1，80周容量保持率为96.52%。

关键词: 锂离子电池, 高镍正极材料, 无钴化, 循环性能

Abstract:

High-performance rechargeable lithium ion batteries have been widely applied in electrochemical energy storage fields, such as, energy storage grids, portable electronic devices, and electric vehicles (EVs). However, the energy density of lithium ion batteries needs to be increased, and the cost of battery materials could be further reduced for wider commercial applications. An Ni-rich cathode, LiNixMnyCo1-x-yO2 (x > 0.8), with high specific capacity is the most promising material for next-generation Li-ion batteries. LiNixMnyCo1-x-yO2 (x > 0.8) contains three transition metal elements, Ni, Mn, and Co, respectively. The role of Ni2+ is to provide high capacity for recharge The role of Mn4+ is to stabilize the lattice structure during charging-discharging cycling. Crucially, the role of Co3+ in Ni-rich materials is to improve the electrical conductivity and inhibit cation disorder in the lattice during electrochemical cycling. However, Co is both in shortage and expensive, which limits its worldwide commercial application. This work investigates substituting Co with other abundant and cheap transition metals. Transition metal ions Cr3+, Cd2+, and Zr4+ can replace Co3+ in Ni-rich cathode materials. LiNi0.8Cr0.1Mn0.1O2, LiNi0.8Cd0.1Mn0.1O2, and LiNi0.8Zr0.1Mn0.1O2 were synthesized by a co-precipitation method. Zr was found to be the best candidate for replacing Co in Ni-rich cathode materials. This study investigated Zr4+-doped Co-free Ni-rich materials. Initially, a carbonate co-precipitation process was used to synthesize Ni0.8Zr0.1Mn0.1CO3. This is due to that Zr3+/Zr4+ ions are not precipitated in the strong alkali solution, and the pH during hydroxide co-precipitation and carbonate co-precipitation processes are approximately 11 and 8, respectively. Therefore, the carbonate co-precipitation synthesis method was chosen. Ni0.8Zr0.1Mn0.1CO3 was synthesized by carbonate co-precipitation at pH = 7.6, 7.8, 8.0, and 8.2. After electrochemical analysis, pH = 7.8 was identified as the optimal value. The next stage of the research involved completing an electrochemical performance comparison on two lithium sources. The following lithium sources were added to the precursor; LiOH·2O, and a 1:1 mixture of LiOH·2O and Li2CO3. The lithium source with the 1:1 mixture, exhibited better performance for the Ni-rich cathode, LiNi0.8Zr0.1Mn0.1O2. In this study, the ideal doping amount of Zr in Ni-rich materials was 0.05. In conclusion, by careful control of co-precipitation pH and Li source, the Zr doped cobalt free Ni-rich cathode LiNi0.85Mn0.1Zr0.05O2 delivered a discharge capacity of 179.9 mAh·g-1 at 0.2C. This was achieved between the voltage range of 2.75-4.3 V, with an 80 cycle capacity retention of 96.52%.

Key words: Lithium ion battery, Nickle-rich cathode material, Cobalt free, Cycling stability