【摘要】 以SiO/C复合材料为负极的锂离子电池相比传统石墨为负极的锂离子电池具有更高能量密度,因而越来越受到开发人员的重视。而SiO/C材料由于Si的存在导致材料本体导电性差,在实体锂离子电池的制作过程中会出现内阻大和倍率性能差等问题,因此导电添加剂组成对电池性能的影响成为研究关键。本文用商业化的LiCoO₂、SiO/复合材料和电解液为主要原料,以VGCF和Super P为导电添加剂,制作了2.5 Ah容量的锂离子软包电池。SEM分析测试表明导电碳黑Super P和VGCF分散均匀,可与SiO/C颗粒形成点和线的接触,进而增强负极极片的导电性能。应用两种导电添加剂所制作的SiO/C锂离子电池的能量密度超过了600 Wh/L。相对于采用Super P导电添加剂,VGCF导电添加剂制备的锂离子电池充放电过程的膨胀更小,且倍率性能更加优异,同时低温和循环寿命均表现出更好的性能。更多还原

【Abstract】 Two conductive additives,carbon black（ Super-P） and vapor-grown carbon fibers（ VGCFs）,were used in 2. 5 Ah Li ion batteries using LiCoO₂ as the cathode and a SiO/C composite as the anode. The electrode shape,peel strength,electrolyte absorption,electrolyte storage capacity,volume change and the electrochemical performance were investigated. Results indicate that both batteries have high energy densities（ more than 600 Wh/L）,but the batteries with VGCFs have the better lowtemperature performance,longer cycle life,higher rate capability and lower volume expansion,which is ascribed to the superior conductive network formed by the VGCFs.更多还原