石墨烯及其复合材料在锂离子电池中的应用

石墨烯是一种单原子层厚度的石墨材料,具有独特的二维结构和优异的电学、力学以及热学性能。同时它也是一种具有良好应用前景的锂离子电池电极材料。电极材料的微观结构对其性能有很大影响,利用石墨烯获得具有特殊形貌和微观结构的电极材料,能有效改善材料的各项电化学性能。本文综述了石墨烯及其复合材料在锂离子电池中的应用研究进展。在负极复合材料中,石墨烯不仅可以缓冲材料在充放电过程中的体积效应,还可以形成导电网络提升复合材料的导电性能,提高材料的倍率性能和循环寿命。通过优化复合材料的微观结构,例如夹层结构或石墨烯片层包覆结构,可进一步提高材料的电化学性能。在正极复合材料中,石墨烯形成的连续三维导电网络可有效提高复合材料的电子及离子传输能力。此外,相比于传统导电添加剂,石墨烯导电剂的优势在于能用较少的添加量,达到更加优异的电化学性能。最后对石墨烯复合材料的研究前景进行了展望。

Graphene-Containing Composite Materials for Lithium-Ion Batteries Applications

Graphene,a one-atom layer of graphite,possesses unique two dimensional structure and excellent electrical,mechanical,and thermal properties.It is considered as one of the most promising candidates for the future electrode materials for lithium ion batteries.Since the microstructure of the electrode material has great influence on its performance,the synthesis of electrode materials with graphene is widely studied to obtain specific morphologies and microstructures with great electrochemical performance improvements.In this review,we highlight recent advancements in the studies of the graphene-containing materials used in lithium ion batteries.Graphene acts as not only a mechanically stable buffer to accommodate the volume effect during cycling,but also a conductive network to enhance the electric conductivity of the anode composite materials.The graphene-containing anode materials can exhibit better cycling and rate performances.Especially,when forming optimized microstructures,such as sandwich-like blocks or other well-controlled encapsulating structures,the graphene can significantly improve electrochemical properties of anode composite materials.A continuous 3D conductive network formed by graphene in the cathode composite materials can effectively improve the electron and ion transportation.Additionally,graphene used as the conductive additive can achieve better charge/discharge performance with a much lower adding amount than those of commercial carbon-based additives.A prospect for future research developments in this field is proposed at the end of this review.