分级过程对LiFePO4/C电池性能的影响

刘兴亮; 杨茂萍; 汪伟伟; 曹勇

doi:10.13208/j.electrochem.160930

电化学 >

2017 , Vol. 23 >Issue 6: 661 - 666

DOI: https://doi.org/10.13208/j.electrochem.160930

研究论文

分级过程对LiFePO₄/C电池性能的影响

刘兴亮 ,
杨茂萍 ,
汪伟伟 ,
曹勇

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合肥国轩高科动力能源有限公司，安徽合肥 230011

收稿日期: 2016-09-30

修回日期: 2017-01-14

网络出版日期: 2017-06-08

基金资助

安徽省科技攻关项目（No. 1501021011）资助

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Effects of jet milling and classifying process on the performance of LiFePO₄/C in full batteries

LIU Xing-liang ,
YANG Mao-ping ,
WANG Wei-wei ,
CAO Yong

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Hefei Guoxuan High-tech Power Energy Co.,Ltd, Hefei, Anhui 230011, China

Received date: 2016-09-30

Revised date: 2017-01-14

Online published: 2017-06-08

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摘要

本文采用磷酸铁工艺路线制备碳包覆的磷酸铁锂（LiFePO₄/C）复合正极材料，系统考察气流粉碎分级过程对LiFePO₄/C正极材料及全电池性能的影响. 研究表明：分级前磷酸铁锂颗粒粒度较大，中值粒径为17.37μm，呈规整球形形貌，具有较高的振实密度和碳含量；分级后球形被打碎，振实减小. 全电池测试结果显示：分级过程对全电池的容量、交流内阻、直流内阻、功率密度的影响较小；但分级前电芯的低温放电容量保持率和550周的高温循环保持率分别60.1%和87.5%，明显优于分级后的49.5%和84.7%. 分级前碳层能均匀包覆在磷酸铁锂表面形成均匀导电网络，而分级过程将磷酸铁锂的碳层有一定的剥离和破坏导致性能下降.

关键词： 磷酸铁锂; 气流粉碎分级; 全电池; 电化学性能

本文引用格式

刘兴亮 , 杨茂萍 , 汪伟伟 , 曹勇 . 分级过程对LiFePO₄/C电池性能的影响[J]. 电化学, 2017 , 23(6) : 661 -666 . DOI: 10.13208/j.electrochem.160930

Abstract

The carbon coated lithium iron phosphate (LiFePO₄/C) composite cathode material was prepared by using iron phosphate process. The effects of jet milling and classifying process on the electrochemical performance of LiFePO₄/C cathode material in full batteries were investigted. Scanning electron microscopic analyses suggested that the globose secondary particles were crustily crushed during the jet milling and classifying process, which would further result in lower tap density and carbon content. The LiFeP₄/C composite cathode materials with different physical characteristics were further tested in full batteries to evaluate the electrochemical properties. The results showed no obvious differences in capacity, AC resistance, DC resistance and power density. However, the globose LiFePO₄/C exhibited far better performances in low temperature discharge capacity retention rate and high temperature cycle retention than that of granulated composite cathode, which probably arisen from the certain delamination and destruction of conductive network during the jet milling and classifying process.

Key words： LiFePO₄/C; jet milling and classifying; full battery; electrochemical performance.

参考文献

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