物理化学学报 >> 2022, Vol. 38 >> Issue (11): 2204057.doi: 10.3866/PKU.WHXB202204057

所属专题: 新锐科学家专刊

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锂离子电池快充石墨负极研究与应用

丁晓博, 黄倩晖, 熊训辉()   

  • 收稿日期:2022-04-29 录用日期:2022-06-06 发布日期:2022-06-13
  • 通讯作者: 熊训辉 E-mail:esxxiong@scut.edu.cn
  • 作者简介:第一联系人:

    These authors contributed equally to this work.

  • 基金资助:
    国家自然科学基金(51874142);中央高校基本科研基金(2019JQ09);广东特支计划“科技创新青年拔尖人才”项目(2019TQ05L903);中国科协青年托举人才项目(2019QNRC001)

Research and Application of Fast-Charging Graphite Anodes for Lithium-Ion Batteries

Xiaobo Ding, Qianhui Huang, Xunhui Xiong()   

  • Received:2022-04-29 Accepted:2022-06-06 Published:2022-06-13
  • Contact: Xunhui Xiong E-mail:esxxiong@scut.edu.cn
  • About author:Xunhui Xiong, Email: esxxiong@scut.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(51874142);the Fundamental Research Funds for the Central Universities(2019JQ09);the Tip-top Scientific and Technical Innovative Youth Talents of Guangdong Special Support Program(2019TQ05L903);the Young Elite Scientists Sponsorship Program by CAST(2019QNRC001)

摘要:

相较于传统燃油汽车,电动汽车缓慢的充电速度始终制约了其进一步推广。为电动汽车实现“加油式”快速充电能够缓解充电桩的使用压力,增加电动汽车的应用场景和市场占有率。因此,亟需开发出具有快速充放电能力的高性能锂离子电池。石墨因其低廉的价格和优异的电化学性能已经在锂离子电池负极领域得到了广泛的商业化应用,然而其较低的嵌锂电位导致在快充过程中出现析锂,损害电化学性能的同时会带来安全隐患。因此,必须对石墨进行改良处理,以适应快充技术的需要。本文系统介绍了近年来石墨负极快充化改良领域的研究进展,从成分设计,形貌调控,结构优化,电解液适配等方面进行了评述,并总结了快充石墨面临的挑战,展望了其发展前景,为推动快充技术的商业化应用提供了借鉴。

关键词: 石墨, 负极, 快充, 锂离子电池

Abstract:

Driven by the excessive environmental pollution caused by the over-use of non-renewable fossil-derived energy, renewable energy and electrochemical energy storage devices have made great progress in the past decades. Electrochemical energy storage devices, such as lithium-ion batteries, have the advantages of high capacity, long life cycle, and good safety performance; therefore, they have been used in various applications. For example, economical and environment-friendly electric vehicles have recently taken up increasing market share. However, when compared with vehicles propelled using fossil-derived energy, the slow charging speed of electric vehicles has always restricted their further promotion. The realization of rapid charging for electric vehicles can alleviate the high-pressure usage of charging piles as well as increase the application and market share of electric vehicles. Therefore, it is important to develop high-performance lithium-ion batteries with rapid charge and discharge capacities. The fast-charging capacity of lithium-ion batteries is limited by the slow migration of lithium ions in the electrode and the electrode/electrolyte interface. Therefore, the key to developing fast-charging lithium-ion batteries lies in the successful design of suitable electrode materials. Because of its low cost and excellent electrochemical performance, graphite has been widely used to develop the cathode of lithium-ion batteries. However, the migration of lithium ions in graphite is slow, resulting in large polarization during the high-current charge and discharge processes. In addition, the low lithium intercalation potential of graphite leads to lithium precipitation during fast charging, which can decrease the electrochemical performance and cause potential safety hazards. Therefore, graphite must be improved to meet the needs of such fast-charging devices. In this article, we systematically introduce the research progress made in recent years within the scope of rapid-charging improvement of graphite(-based) cathodes and then highlight the modification strategies for graphite with the goal of achieving functional coating, desired morphological and structural design, optimized electrolyte properties, and an improved charging protocol. Additionally, this article evaluates the advantages and disadvantages of the modification strategies as well as their application prospects. The scheme of functional coating for modifying graphite must simplify the process and improve production efficiency to meet the needs of industrial development. Morphology design should ensure satisfactory initial Coulomb efficiency, while the improvement of the electrolyte properties and optimization of the charging protocol need to consider the commercialization costs. Finally, this paper proposes further evaluation of the effects of the modification strategies based on soft-pack or cylindrical batteries to strengthen the commercialization prospect of the modification strategies.

Key words: Graphite, Negative pole, Fast charging, Lithium ion battery

MSC2000: 

  • O646