膨胀石墨的低温制备及储能性能研究

摘要

Graphite Oxide (GO) was prepared by a modified Hummer's method.The resulting GO product was modified by a hydrothermal treatment and finally dried in vacuum.XRD,SEM,FTIR,Raman and electrochemical testing were employed to characterize the structure properties,morphology properties and electrochemical performance of the product materials.Results show that expanded graphite is obtained by hydrothermal method.A new method,named low temperature hydrothermal,was proposed to prepare expanded graphite.This method could avoid high temperature calcinations,thus reduce the loss and cost of the energy.Expanded graphite was used as the cathode material of lithium-ion capacitor (LIC).The material could deliver a discharge capacity of 43 mAh/g at 100 mA/g,and it had along cycle life up to 2 000 cycles with near 100％ capacity retention.%采用改进的Hummers法制备氧化石墨,并对氧化石墨进行水热处理和后处理,得到了最终产物样品.通过对产物样品进行X射线衍射分析(XRD)、扫描电子显微镜(SEM)、红外光谱测试(FIR)及拉曼测试(Raman),研究了其形貌、结构和化学键结合,同时并对其电化学性能进行表征,研究结果发现,通过对氧化石墨简单水热处理后,得到了膨胀石墨.提出了一种制备膨胀石墨的新方法,即低温水热法,此方法可以避免高温烧结的过程,降低了能耗并减少了成本.将其用于锂离子电容器正极材料,在100 mA/g的电流密度下,其放电比容量达到43 mAh/g,循环稳定性较好,容量保持率接近100％.