(1. 中南大学 冶金与环境学院,长沙 410083;
2. 深圳好电科技有限公司,深圳 518057)
摘 要: 利用导电炭黑和导电石墨两款碳材料制作涂碳铝箔,将其作为锂硫电池正极的集流体,考察箔材种类对电极性质和电池性能的影响规律。结果表明:所制作的涂碳铝箔具有“点-面”结合的导电架构,其不仅可以改善硫电极的导电性,而且有利于增强活性物质与集流体的粘结性、抑制电解液对铝箔的腐蚀。涂碳铝箔可以显著降低电池的极化阻抗,维持稳定的充放电平台。相比使用传统铝箔,使用涂碳铝箔的电池的活性物质利用率更高,循环性能更为优异,经0.2C充放电循环40次后,其放电容量达到602 F/g,容量保持率为77.7%。
关键字: 锂硫电池;导电碳;涂碳铝箔;集流体;电化学性能
(1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Shenzhen Perfect Power Technology Co., Ltd., Shenzhen 518057, China)
Abstract:The carbon-coated aluminum (Al) foil was prepared by mixing two conductive carbon materials (carbon black+graphite) and studied as a current collector of Li-S battery. The effects of foil type on the electrode properties and cell performance were investigated. The results show that the carbon-coated Al foil possesses a point-surface combined conductive framework between active material layer and Al foil layer, which not only improves the conductivity of the sulfur electrode, but also enhances the adhesion of active material to current collector and inhibits the corrosion of the electrolyte to Al substrate. When using carbon-coated Al foil, the cell polarization is significantly reduced and stable charge-discharge platform is maintained. Compared to common Al foil, the carbon-coated Al foil favors more utilization of active material and more excellent cycle performance. The retained capacity reaches 602 F/g and capacity retention is 77.7% for the cell loading carbon-coated Al foil after 40 cycles at rate of 0.2C.
Key words: lithium sulfur battery; carbon-coated aluminum foil; current collector; electrochemical performance