储能科学与技术 ›› 2024, Vol. 13 ›› Issue (11): 4124-4132.doi: 10.19799/j.cnki.2095-4239.2024.0560

• 储能测试与评价 • 上一篇    下一篇

焦磷酸磷酸铁钠基钠离子电池日历老化容量衰减机理研究

赵瑞瑞1(), 彭燕秋1, 赖学君1, 吴志隆1, 高杰1, 许文成1, 王立娜1, 丁沁1, 方永进2, 曹余良2()   

  1. 1.惠州亿纬锂能股份有限公司,广东 惠州 516006
    2.武汉大学化学与分子科学学院,湖北 武汉 430072
  • 收稿日期:2024-06-21 修回日期:2024-07-14 出版日期:2024-11-28 发布日期:2024-11-27
  • 通讯作者: 曹余良 E-mail:029018@evebattery.com;ylcao@whu.edu.cn
  • 作者简介:赵瑞瑞(1988—),女,博士,工程师,主要研究方向先进电池材料与技术,E-mail:029018@evebattery.com
  • 基金资助:
    广东省重点领域研发计划项目(2023B0909020001)

Capacity fading mechanism of Na4Fe3(PO4)2P2O7 based sodium-ion battery during calendar aging

Ruirui ZHAO1(), Yanqiu PENG1, Xuejun LAI1, Zhilong WU1, Jie GAO1, Wencheng XU1, Lina WANG1, Qin DING1, Yongjin FANG2, Yuliang CAO2()   

  1. 1.EVE Energy Co. , Huizhou 516006, Guangdong, China
    2.College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, China
  • Received:2024-06-21 Revised:2024-07-14 Online:2024-11-28 Published:2024-11-27
  • Contact: Yuliang CAO E-mail:029018@evebattery.com;ylcao@whu.edu.cn

摘要:

随着钠离子电池技术的不断发展,深入探索其存储过程中的容量损失机理对提高电池系统日历寿命具有重要意义。本文对焦磷酸磷酸铁钠[Na4Fe3(PO4)2P2O7]基钠离子电池的高温存储性能进行了详细研究,通过透射电子显微镜(TEM)、电感耦合等离子体发射光谱(ICP)、拉曼光谱、傅里叶变换红外光谱(FT-IR)及X射线光电子能谱(XPS)等多维度分析技术,全面剖析了正负极活性材料在高温存储过程中的容量损失率、结构、形貌及界面组分的变化。研究结果表明,高温存储后电极活性材料的比容量仅出现轻微衰减,正负极活性材料结构也未见受损,且正极铁元素溶出串扰并不显著。然而,负极侧固体电解质界面(SEI)膜增厚现象十分显著,表明存储期间负极SEI膜会不断溶解生长,且新生成的SEI膜以有机物为主。这一发现揭示了负极侧界面副反应是钠离子电池存储容量损失的主要因素。本研究不仅深化了对钠离子电池日历老化机制的理解,也为后续提升电池性能提供了重要的科学依据。

关键词: 钠离子电池, 日历老化, 容量衰减机理, 固体电解质膜, Na4Fe3(PO4)2P2O7正极

Abstract:

The ongoing advancements in sodium-ion battery technology necessitate an in-depth understanding of capacity fading mechanisms during high-temperature storage to enhance the calendar life of these battery systems. This study systematically investigates the high-temperature storage performance of Na4Fe3(PO4)2P2O7-based sodium-ion batteries. A comprehensive analysis was conducted using multiple techniques, including transmission electron microscopy (TEM), inductively coupled plasma emission spectroscopy(ICP), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy(XPS) , to assess changes in specific capacity, structural integrity, morphology, and interfacial components of both cathode and anode active materials during storage. Results reveal a slight decrease in electrode specific capacity after storage, without significant structural damage to the cathode or anode. Iron dissolution from the cathode was minimal, showing negligible crosstalk. However, the solid electrolyte interphase (SEI) on the anode thickened significantly, with the SEI layer dissolving and regenerating continuously, primarily composed of organic components. These findings indicate that side reactions at the anode interface are the primary contributors to capacity loss during high-temperature storage. This work deepens the understanding of the calendar aging process in sodium-ion batteries and provides critical scientific insights for enhancing sodium-ion battery performance.

Key words: sodium-ion batteries, storage, calendar aging, capacity fading mechanism, solid electrolyte interphase, Na4Fe3(PO4)2P2O7 cathode

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