储能科学与技术 ›› 2023, Vol. 12 ›› Issue (10): 3049-3055.doi: 10.19799/j.cnki.2095-4239.2023.0396

• 储能材料与器件 •    下一篇

铬氧化物作为高容量锂电池正极材料的制备及其性能研究

孟庆飞1(), 杨睿2, 金成龙1, 曹余良2(), 李文杰1, 周舟1, 吴际良1()   

  1. 1.武汉中原长江科技发展有限公司,湖北 武汉 430090
    2.武汉大学化学与分子科学学院,湖北 武汉 430072
  • 收稿日期:2023-06-07 修回日期:2023-07-20 出版日期:2023-10-05 发布日期:2023-10-09
  • 通讯作者: 曹余良,吴际良 E-mail:mqf2161@163.com;ylcao@whu.edu.cn;wujil@163.com
  • 作者简介:孟庆飞(1984—),男,硕士,高级工程师,研究方向为化学电源,E-mail:mqf2161@163.com
  • 基金资助:
    国防基础科研计划资助(JCKY2021211B014)

Preparation and performance of high-capacity Cr8O21 as a cathode material for lithium batteries

Qingfei MENG1(), Rui YANG2, Chenglong JIN1, Yuliang CAO2(), Wenjie LI1, Zhou ZHOU1, Jiliang WU1()   

  1. 1.Wuhan Zhongyuan Changjiang Technology Development Co. , Ltd. , Wuhan 430090, Hubei, China
    2.College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, China
  • Received:2023-06-07 Revised:2023-07-20 Online:2023-10-05 Published:2023-10-09
  • Contact: Yuliang CAO, Jiliang WU E-mail:mqf2161@163.com;ylcao@whu.edu.cn;wujil@163.com

摘要:

氧化铬(Cr8O21)由于具有高比容量、高电压与低成本,成为高比能量锂电池正极材料的研究热点。本工作以CrO3为前驱体,在氧气氛围下,通过一步煅烧法制得了高纯度的Cr8O21。利用X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)以及电化学测试技术,对不同热解条件下产物的成分以及形貌进行了分析讨论,并对其作为锂电池正极材料的电化学性能进行了测试。研究结果表明,煅烧温度对氧化铬的电化学性能影响很大。较低温度下会有部分CrO3未反应,电极容易被腐蚀损坏。而在较高的温度下,生成的Cr2O5杂相会降低电极材料的比容量。最终得到的优化条件为煅烧温度270 ℃,煅烧时间24 h,所得到的Cr8O21纯度最高且具备最佳的电性能。在0.1 C倍率下,首次放电可逆比容量高达357 mAh/g,平均放电电压为3 V。同时,对电池进行20周循环后,放电容量能保持在80%以上。最后,对所制备氧化铬的高低温放电性能也进行了研究,在-45 ℃和65 ℃下,其放电比容量分别为200 mAh/g和364 mAh/g,表明其具备良好的循环稳定性和电化学性能。

关键词: 氧化铬, 正极材料, 锂电池

Abstract:

Chromium oxide with high capacity, high voltage, and low cost has drawn much attention as a cathode material for lithium batteries. This study prepares high pure-phase Cr8O21 through one-step pyrolysis under oxygen atmosphere with CrO3 as precursor. The chemical composition, morphology, and corresponding electrochemical performance of the samples prepared at different pyrolysis conditions are analyzed through X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and electrochemical techniques. The results show that the pyrolysis temperature greatly affects the electrochemical performance of chromium oxides. The insufficient decomposition of CrO3 at lower temperatures results in electrode damage, and the impurity phase of Cr2O5 formed during pyrolysis under higher temperatures significantly reduces the specific capacity. Cr8O21 prepared at 270 ℃ for 24 h exhibits an outstanding performance with a high specific capacity of 357 mAh/g at first discharge under 0.1 C and an average voltage reaching 3 V. The capacity retention exceeds 80% after a 20-cylce test. In addition, high specific capacities of 200 and 363 mAh/g are achieved at -45 ℃ and 65 ℃, respectively, indicating the excellent cycling stability and electroactivity of Cr8O21.

Key words: chromium oxides, cathode materials, lithium battery

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