球磨法制备锂离子液流电池石墨负极浆料的性能研究

采用球磨法制备锂离子液流电池所用的石墨负极浆料,并对石墨负极浆料的颗粒形貌、电导率、比容量性能及循环性能进行研究。结果表明:导电添加剂的加入有助于提高电极浆料的悬浮稳定性;球磨过程可以降低石墨和导电添加剂混合粉体的电阻率,球料比达到5∶1时即可实现较好的球磨效果,但球料比不宜过高,否则会造成石墨材料层状结构的破坏,影响电极浆料性能的稳定性。提高石墨和导电添加剂的含量可以在电极浆料中形成稳定的导电网络结构,使可逆比容量提高;在保证电极浆料可流动的情况下,可逆比容量可大于40mAh/g。石墨负极浆料的容量损失主要发生在首次充放电过程中,随着循环次数的增加,容量损耗的速率降低,第5次循环以后容量趋于稳定。

Performance Study of Graphite Anode Slurry in Lithium-ion Flow Battery by Ball Milling

Graphite anode slurry of lithium-ion flow battery was prepared by the method of ball mill-ing .The morphology ,conductivity ,specific capacity and cycle performance of graphite anode slurry were studied .Results show that the addition of conductive carbon material can improve the suspension stability of the electrode slurry ;the ball milling process can not only improve the suspension stability but also reduce the resistivity of the mixed powders of graphite and conductive carbon materials ,the ball milling effect is satisfactory when the mass ratio of the balls and the solid particles is 5:1 ,but too high ratio of the milling ball and the solid materials can destroy the layer structure of the graphite and affect the stability of the slurry .Increasing the fraction of the graphite and conductive carbon ma-terials can form stable electrical network structure in the slurry and improve the reversible capacity ;at the premise of keeping the flowability of the electrode slurry ,the reversible specific capacity can be more than 40mAh/g .The capacity loss of graphite anode slurry mainly occurs in the first charging-discharging process ,as the increase of the cycles ,the capacity loss rate decreases ,the capacity goes stable after 5 cycles.