失效锂离子电池石墨负极回收利用研究进展

Progress on recycling graphite cathode from spent lithium-ion batteries

  • 摘要: 新能源汽车产业发展是实现我国“双碳”战略的重要举措. 石墨因其高导电率、高容量和高稳定性等优点,成为当前主流的负极材料,其需求量和报废量增长迅速. 废石墨负极因含多种金属、黏结剂、电解液等,具有污染性和资源性双重特点,其高效清洁回收利用成为人们研究的热点与重点问题. 首先介绍了全球石墨矿产资源分布及其消费结构,表明我国石墨资源较为丰富(约占全球15.7%),但产量与消费量全球第一,分别达到65.4%和86.6%,且电池负极消费比重日益增长. 为提高石墨负极利用水平,系统综述了石墨负极回收利用研究进展,阐述了石墨负极的再生方法,包括物理法、湿法浸出、火法及其他方法. 为进一步提高再生石墨负极的电化学性能,改性技术(如元素掺杂、碳包覆、复合等方法)也受到人们的广泛关注. 此外,还概括了石墨负极合成的其他新型功能材料,如石墨烯及氧化石墨烯、电容器、吸附剂和催化剂等,为石墨负极高值利用提供了新的选择. 最后,总结了负极石墨材料回收利用的技术瓶颈和面临的挑战,为其绿色高效循环利用提供了研究思路和发展方向.

     

    Abstract: The rapid development of the new energy vehicle industry promotes the achievement of “dual-carbon” goals. Graphite has become the mainstream cathode material because of its high conductivity, capacity, and stability. Demand for graphite and the importance of end-of-life issues have grown rapidly with the booming of the Li-battery vehicle industry. Waste graphite cathodes are important resources of valuable materials, including Li, Cu, and graphite. However, they are also classified as solid wastes and cause potential environmental issues owing to the presence of binders, electrolytes, fluoride, etc. Hence, efficient and clean recycling of spent graphite has recently attracted considerable attention. In this review, the global distribution of mineral resources and the consumption structure of graphite are introduced. The graphite mineral reserve in China is quite abundant, approximately 15.7% of the world’s reserves. Meanwhile, the production and consumption of graphite in China is 65.4% and 86.6% of the global total, respectively. Its use in batteries as anodic materials is increasing. To improve the recycling technology of graphite cathodes, the progress in recycling them from spent lithium-ion batteries is reviewed systematically. Recycling methods, including physical separation, hydrometallurgical leaching, pyrometallurgy, and other methods, are elaborated. Graphite modification methods (e.g., element doping, carbon coating, and material compositing) used to enhance the electrochemical properties of regenerated graphite are summarized. Furthermore, the preparation of new functional materials from waste graphite has attracted considerable attention, for example, its reuse as graphene and graphene oxide, capacitors, adsorbents, and catalysts. However, because of the differences in graphite anode material manufacturers and various situations of failures and damage levels, obtaining uniform high-performance graphite products is highly challenging. The environmental issues arising from the disposal of electrolytes, organic binders, and hazardous metal ions in wastewater cannot be ignored. Currently, recovery technologies are complex and can only achieve a single goal, such as the purification of graphite by acid leaching. Therefore, a short, low-cost, and efficient process must be developed to achieve high-performance graphite products. More importantly, for graphite anode regeneration and reuse, the corresponding product standard system must be established to promote the industrial application of waste graphite anode recycling.

     

/

返回文章
返回