搜索

x
中国物理学会期刊

富锂正极材料在全固态锂电池中的研究进展

CSTR: 32037.14.aps.72.20230258

Research advance of lithium-rich cathode materials in all-solid-state lithium batteries

CSTR: 32037.14.aps.72.20230258
PDF
HTML
导出引用
  • 开发高能量密度、长循环寿命、低成本和高安全性的全固态锂电池是发展下一代锂离子电池的重要方向之一. 富锂层状氧化物正极材料由于阴阳离子协同参与氧化还原反应, 可以提供更高的放电比容量(>250 mAh/g)和能量密度(>900 Wh/kg), 将其应用于全固态锂电池中有望推动锂离子电池能量密度突破500 Wh/kg的中长期目标. 然而, 富锂正极材料的电子导电性差、阴离子氧的不可逆氧化还原反应以及循环中的结构相变, 导致该材料在电化学循环过程中存在初始库仑效率低、循环稳定性差和电压衰退等问题. 此外, 富锂正极材料的工作电压较高(> 4.5 V vs. Li/Li+), 使正极/电解质之间不仅面临常规的界面化学反应, 释放的氧还会加剧界面的电化学反应, 对正极/电解质的界面稳定性提出了更高的要求. 因此, 富锂正极材料的本征特性和富锂正极/电解质间严重的界面反应极大限制了富锂正极材料在全固态锂电池中的应用. 本文首先详细阐述了富锂正极材料在全固态锂电池中的失效机制, 其次综述了近年来富锂正极材料在不同固态电解质体系下的研究进展, 最后总结和展望了富锂全固态锂电池未来的研究重点和发展方向.

     

    The development of all-solid-state lithium batteries with high energy density, long cycle life, low cost and high safety is one of the important directions for the developing next-generation lithium-ion batteries. Lithium-rich cathode materials have been widely used in liquid lithium batteries for their higher discharge specific capacity (> 250 mAh/g) and energy density (> 900 Wh/kg), high thermal stability and low raw material cost. With the rapid development of high-performance lithium-rich cathode materials and solid-state electrolytes in all-solid-state lithium batteries, the application of lithium-rich cathode materials in all-solid-state lithium batteries is expected to make a breakthrough toward the target of 500 Wh/kg energy density of lithium-ion batteries. In this review, first, we elaborate the failure mechanism of lithium-rich cathode materials in all-solid-state lithium batteries. The poor electronic conductivity, irreversible redox reaction of anionic oxygen and structute transformation during the electrochemical cycling of lithium-rich cathode materials result in the low initial coulomb efficiency, poor cycling stability and voltage decay. In addition, the high operating voltage of lithium-rich cathode materials (> 4.5 V vs. Li/Li+) triggers off not only the conventional interfacial chemical reactions between anode and electrolyte, but also the release of oxygen, aggravating the interfacial electrochemical reactions, which reduces the stability of the cathode/electrolyte interface. Therefore, the intrinsic characteristics of lithium-rich cathode materials and the severe interfacial reaction of lithium-rich cathode/electrolyte greatly limit the application of lithium-rich cathode materials in all-solid-state lithium batteries. Then, we review the research progress of lithium-rich cathode materials in various solid-state electrolyte systems in recent years. The higher room temperature ionic conductivity and wider voltage window of inorganic solid-state electrolytes provide opportunities for the application of lithium-rich cathode materials in all-solid-state lithium batteries. At present, the application of lithium-rich cathode materials in all-solid-state lithium batteries is explored on the basis of sulfide, halide and oxide solid-state electrolyte systems, and important progress has been made in the studies of composite cathode preparation methods, interfacial reaction mechanisms and activation mechanisms. Finally, we summarize the current research hotspot of lithium-rich cathode all-solid-state lithium batteries and propose several strategies for their future studies, such as the regulation of cathode material components, the construction of lithium ion and electron transport pathways within the composite cathode, and the interfacial modification of cathode materials that have been shown to have significant effects in solving the failure problem.

     

    目录

    /

    返回文章
    返回