储能科学与技术 ›› 2024, Vol. 13 ›› Issue (3): 742-748.doi: 10.19799/j.cnki.2095-4239.2023.0741

• 储能材料与器件 • 上一篇    下一篇

Al-Y-Zr原位共掺杂提高4.53 V钴酸锂正极材料的循环性能

胡大林1(), 任潘利1, 张昌明1, 杨明阳2, 卢周广2()   

  1. 1.南科大材料系-豪鹏科技新能源联合实验室,深圳市豪鹏科技股份有限公司,广东 深圳 518111
    2.南科大材料系-豪鹏科技新能源联合实验室,深圳市界面材料界面科学与工程 应用重点实验室,南方科技大学材料科学与工程系,广东 深圳 518055
  • 收稿日期:2023-10-24 修回日期:2023-11-15 出版日期:2024-03-28 发布日期:2024-03-28
  • 通讯作者: 胡大林,卢周广 E-mail:David.hu@highpowertech.com;luzg@sustech.edu.cn
  • 作者简介:胡大林(1982—),男,博士,高级工程师,研究方向为锂离子电池,E-mail:David.hu@highpowertech.com
  • 基金资助:
    国家自然科学基金(U22A20439);深圳市基础研究重点项目(JCYJ20220818100418040)

Improving the cycling performance of LiCoO2 at 4.53 V via in situ co-doping of Al-Y-Zr

Dalin HU1(), Panli REN1, Changming ZHANG1, Mingyang YANG2, Zhouguang LU2()   

  1. 1.SUSTech MSE - Highpower Technology Joint Laboratory of New Energy Technology, Shenzhen Highpower Technology Co. , Ltd. , Shenzhen 518111, Guangdong, China
    2.SUSTech MSE-Highpower Technology Joint Laboratory of New Energy Technology, Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials, Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China
  • Received:2023-10-24 Revised:2023-11-15 Online:2024-03-28 Published:2024-03-28
  • Contact: Dalin HU, Zhouguang LU E-mail:David.hu@highpowertech.com;luzg@sustech.edu.cn

摘要:

钴酸锂是一种成功实现商业化的锂离子电池正极材料,但其实际的容量远低于其理论容量(274 mAh/g)。提高钴酸锂的充电截止电压能够有效提高其放电容量,但钴酸锂在高压条件下结构不稳定性,导致其循环寿命明显降低。本工作提出一种Al-Y-Zr原位共掺杂的策略,以提高钴酸锂在4.53 V的循环性能。通过将Al-Y-Zr掺杂的Co3O4、Li2CO3、MgO按一定化学计量比称取并混合均匀后,采用高温固相法合成LiCo(1-a-b-c-dAl a Zr b Y c Mg d O2正极材料,并探究了原位共掺杂对高电压钴酸锂循环性能的影响。X射线衍射(XRD)表明掺杂前后晶体均为六方相层状结构,扫描电镜(SEM)说明了掺杂元素对晶体颗粒粒径的调控作用。循环前后的电化学阻抗谱(EIS)表明,Al-Y和Al-Y-Zr共掺杂能有效抑制循环过程中电荷转移阻抗(Rct)的增长。扣式电池及软包电池测试结果都表明Al-Y和Al-Y-Zr前驱体共掺杂能够显著提升循环性能,后者提升更明显。本研究有助于推动高电压钴酸锂正极的应用,为高比能量锂离子电池技术的研发提供实验依据。

关键词: 锂离子电池, 钴酸锂, 高电压, 共掺杂, 循环性能

Abstract:

The LiCoO2 is a commercially successful lithium-ion battery cathode material; however, its actual capacity falls short of its theoretical capacity (274 mAh/g). Increasing the charging cutoff voltage can boost discharge capacity; however, the instability of LiCoO2 under high voltage compromises its cycle life. This study aims to introduce an in situ co-doping strategy with Al-Y-Zr to enhance the cycling performance of LiCoO2 at 4.53 V. The LiCo(1-a-b-c-d)Al a Zr b Y c Mg d O2 cathode material was synthesized using a high-temperature solid-phase method by mixing Al-Y-Zr-doped Co3O4, Li2CO3, and MgO in a specific stoichiometric ratio. The impact of in situ co-doping on high-voltage LiCoO2's cycling performance was investigated. X-ray diffraction revealed a hexagonal layered crystal structure before and after doping, whereas scanning electron microscopy confirmed the regulation of crystal particle size by the doping elements. Electrochemical impedance spectroscopy demonstrated that the co-doping of Al-Y and Al-Y-Zr effectively inhibits growth of Rct value during cycle testing. Test results from coin and pouch cells showed that in situ co-doping substantially improves the cycling performance, with the latter displaying substantial pronounced enhancement. This study contributes to advancing the application of high-voltage lithium cobalt oxide cathodes. In addition, it provides an experimental foundation for research and development in high-specific-energy lithium-ion battery technology.

Key words: Li ion batteries, LiCoO2, high voltage, co-doping, cyclic performance

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