储能科学与技术 ›› 2023, Vol. 12 ›› Issue (2): 329-338.doi: 10.19799/j.cnki.2095-4239.2022.0537

• 储能材料与器件 •    下一篇

颗粒级配对锂浆料电池性能的影响

高桂红1(), 李珅珅1, 刘福园1, 巫湘坤2, 刘艳侠1,2()   

  1. 1.郑州中科新兴产业技术研究院,河南省储能材料与过程重点实验室,河南 郑州 450003
    2.中国科学院过程工程研究所,离子液体清洁过程北京重点实验室,北京 100190
  • 收稿日期:2022-09-20 修回日期:2022-11-09 出版日期:2023-02-05 发布日期:2023-02-24
  • 通讯作者: 刘艳侠 E-mail:1019660339@qq.com;yxliu@ipe.ac.cn
  • 作者简介:高桂红(1985—),女,硕士,工程师,研究方向为储能及动力电池技术,E-mail:1019660339@qq.com
  • 基金资助:
    国家重点研发计划项目(2019YFA0705604);国家自然科学基金项目(22078341);河南省重点研发计划项目(221111240100)

Study on the influence of particle composition on the performance of lithium slurry batteries

Guihong GAO1(), Shenshen LI1, Fuyuan LIU1, Xiangkun WU2, Yanxia LIU1,2()   

  1. 1.Zhengzhou Institute of Emerging Industrial Technology, Henan Key Laboratory of Energy Storage Materials and Processes, Zhengzhou 450003, Henan, China
    2.Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academyof Sciences, Beijing 100190, China
  • Received:2022-09-20 Revised:2022-11-09 Online:2023-02-05 Published:2023-02-24
  • Contact: Yanxia LIU E-mail:1019660339@qq.com;yxliu@ipe.ac.cn

摘要:

利用大小颗粒之间的填充效应,本文设计了2种粒径的活性颗粒组成7种级配体系,并系统研究了其浆料的性能。借助激光粒度仪、电导率仪、比表面测试仪、扫描电子显微镜、沉降测试和电化学测试等手段分析了样品粒度分布、比表面积、颗粒形貌、浆料的电导率、沉降率、电化学阻抗谱和充放电性能。结果表明,所有级配粒径分布均呈单峰接近正态分布;级配颗粒属于大孔或者无孔材料;小颗粒是典型的单晶结构,大颗粒由球形大颗粒构成,3∶7和0∶10样品扫描电子显微镜图显示大粒径周围被小粒径和导电剂包围着,形成了完整连续的三维导电网络;大颗粒组成的浆料电导率为41.80 mS/cm,小颗粒组成的浆料电导率高达123.39 mS/cm;3∶7样品浆料的沉降率和沉降速率最小,颗粒级配更接近Fuller最密充填粒度分布经验曲线;3∶7和5∶5样品0.1 C的放电比容量分别达到194.88 mAh/g和187.38 mAh/g,实际比容量发挥分别高于商业典型值10%、5%以上,首次充放电效率高达90.54%、87.96%。此外,3∶7样品电池还表现出最优异的循环性能,经循环250次后,容量保持率为83.63%。总之,级配为3∶7样品的颗粒填充效应得到充分发挥,表现出最优异的性能。本文提供了最佳比例的颗粒级配设计比,为优异性能的颗粒级配提供重要参考。

关键词: 粒径级配, 锂浆料, 电池, 富勒级配曲线

Abstract:

Based on the filling effect between large and small particles, we designed seven grading systems using two sizes of active particles and studied the performance of the slurry systematically. The particle size distribution, surface area, particle morphology, electrical conductivity, sedimentation rate, electrochemical impedance spectrum, and charging and discharging properties of the slurry were analyzed using a laser particle size analyzer, conductivity meter, specific surface area measuring instrument, scanning electron microscope (SEM), sedimentation test, and electrochemical test. The results indicate that the particle distribution is a single peak close to the normal distribution. The particles have either macroporous or nonporous structures. The small particles are typical single-crystal structures, and the large particles comprise spherical particles with relatively larger diameters. The SEM images of 3∶7 and 0∶10 samples show that a large particle is surrounded by small particles and a conductive agent, forming a complete continuous three-dimensional conductive network. The conductivity of slurry formed by large particles is 41.80 mS/cm, and that of slurry formed by small particles can be as high as 123.39 mS/cm. The 3∶7 sample's sedimentation and settling rates are the smallest, and the particle distribution is closer to Fuller's grading curve of densely packed particles. The 0.1 C specific discharge capacity of the 3∶7 and 5∶5 samples reached 194.88 and 187.38 mAh/g, respectively, with actual specific capacities 10% and 5% higher than the commercial typical values, and the first cycle charging-discharging efficiencies were as high as 90.54% and 87.96%, respectively. Moreover, the best cycling performance of 83.63% capacity retention after 250 cycles was provided by the 3∶7 sample. In summary, the 3∶7 sample showed the most effective filling effect and best electrochemical performance. In this study, we could realize the best particle ratio grading system, providing an essential reference for particle gradation systems with excellent performance.

Key words: grain composition, lithium slurry, battery, fuller's grading curve

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