高性能锂离子电池正极黏合剂研究进展

正极黏合剂是维持锂离子电池正极结构稳定性的关键材料,对于锂离子电池的能量密度及安全性具有重要作用.本文综述了锂离子电池正极黏合剂材料的研究及应用进展,重点介绍了锂离子电池正极黏合剂对于正极材料及锂离子电池电化学性能的影响,详细总结了以聚偏氟乙烯(PVDF)、聚酰亚胺(PI)、功能性聚合物黏合剂为代表的油溶性黏合剂和以聚丙烯酸(PAA)、羧甲基纤维素(CMC)为代表的水溶性黏合剂的特点:PVDF具备良好的化学稳定性,黏合效果较好,但耐高温性能差且在电解液中易溶胀;PI的耐高温性能优异,机械性能较好,但成本相对较高;功能性聚合物黏合剂具备良好的导电性,可有效抑制Li-S锂电池中多硫化物的穿梭效应,但制备工艺复杂;PAA的柔性较好,抗高压能力较强,但是力学性能较差;CMC具有良好的分散性,机械强度较大,因脆性较大需与丁苯橡胶(SBR)配合使用.结合已有的研究报道,探讨了高性能锂离子电池先进正极黏合剂材料的未来发展方向及前景.

Research Progress of Cathode Binder for High Performance Lithium-ion Battery

Developing high-performance battery systems requires the collaborative optimization of every battery components, including electrodes, electrolyte, separators and binder systems. The strategies of synthesizing electrode materials and developing novel electrolyte system are widely investigated. Cathode binder, a crucial material to maintain structure stability of cathode, plays an essential role in efficiently enhancing energy density and ensuring safety of lithium ion battery. In recent years, designing advanced binder systems has attracted researchers’ attention. In this account, the research progress on material and structural design of cathode binder and application about cathode binder of lithium ion battery are reviewed comprehensively. The effects that cathode binders play on stabilizing cathode material, promoting reduction of battery internal impedance and regulating electrochemical performances of lithium ion battery are primarily introduced. Meanwhile, the characteristics of the oil-soluble binder represented by poly(vinylidene fluoride)(PVDF), polyimide(PI), functional polymer binder and the water-soluble binder represented by poly(acrylic acid)(PAA) and carboxymethyl cellulose(CMC) are concluded in detail. PVDF has good chemical stability and adhesion, but suffers from large swelling ratio;PI has excellent high temperature resistance and good mechanical properties, but the cost is relatively high;functional polymer binder has good electrical conductivity and can effectively suppress the shuttle effect of Li-S lithium batteries, but the preparation process is complicated;PAA is flexible, but mechanical properties are poor;CMC has good dispersibility and large mechanical strength, but it needs to be matched with styrene-butadiene rubber due to the large brittleness. Furthermore, combining with the existing research reports, methods of designing advanced cathode binder systems are concluded to provide valuable guidance for the performance optimization.The development prospects and application exploration are also discussed.