基于石墨烯的全固态平面超级电容器研究

发布时间：2018-06-01 02:27

  本文选题：平面超级电容器 + 石墨烯　； 参考：《哈尔滨理工大学》2017年硕士论文

【摘要】：随着小型化和可穿戴式电子产品的不断发展,人们对微型存储系统的需求日益迫切。平面超级电容器在保证高储能密度、高充放电速率和良好循环稳定性的基础上,可与便携式电子产品高度兼容,实现了微型储能器件功能集成化的要求。石墨烯是由sp2杂化碳原子结合形成的单原子层二维薄膜,作为凝聚态物理领域的新成员,因其独特的力学性能和电学性能,能够满足储能器件对电极材料的所有要求。本文基于化学气相沉积法原理,通过探究不同生长条件对石墨烯薄膜质量的影响,得到最佳制备工艺参数。实验结果表明:在低压条件下,石墨烯随着生长时间、生长温度和碳源浓度的增加而增厚。单层石墨烯的生长条件为:在1000℃的恒温状态下,通入流量为35sccm的CH4生长30min,该条件下所得薄膜透光率为95.2%,薄膜方阻为155.75?/sq。多层石墨烯生长条件为:在1000℃的恒温状态下,通入流量为35sccm的CH4生长60min;在1000℃生长温度下,65sccm的CH4流量,生长30min得到的多层石墨烯拥有较小方阻约为60.28?/sq,但薄膜表面均一性较差。通过多次转移单层石墨烯得到的多层石墨烯薄膜,在波长为550nm的可见光处的透光率为97.2%,比在1000℃生长温度下,35sccm的CH4流量,10sccm的H2流量的条件下生长30min得到的单层石墨烯透光性能好,但阻值较高。用自制和购买的单层、多层石墨烯薄膜作为平面超级电容器电极,制备全固态平面超级电容器,通过循环伏安测试探究其超级电容特性。实验结果表明:随着扫描速率的减小,平面超级电容器的循环伏安特性曲线越接近梭形,器件的电化学性能越好。当扫描速率为20mVs-1时,自制单层石墨烯超级电容器的面积比电容为62.924mFcm-2,能量密度为320.117mWhcm-3,远大于购买单层石墨烯超级电容器性能值;当扫描速率为100mVs-1时,购买的多层石墨烯超级电容器的面积比电容为23.642mFcm-2,能量密度为47.511mWhcm-3,远大于购买的单层石墨烯超级电容器性能值;当扫描速率为20mVs-1时,多层转移得到的多层石墨烯平面超级电容器的面积比电容为20.464mFcm-2,能量密度仅为1.312mWhcm-3。综上所述,本论文对优化CVD法制备石墨烯薄膜电极工艺的研究取得良好成果,多层转移石墨烯薄膜制备工艺还有待提高,本文为基于CVD法制备石墨烯电极的全固态平面微型超级电容器提供了重要参考。
[Abstract]:With the development of miniaturization and wearable electronic products, the demand for micro storage system is becoming more and more urgent. On the basis of high energy storage density, high charge / discharge rate and good cycle stability, planar supercapacitors can be highly compatible with portable electronic products and achieve the functional integration requirements of micro energy storage devices. As a new member of condensed matter physics, graphene is a two-dimensional monatomic film formed by sp2 hybrid carbon atom. Because of its unique mechanical and electrical properties, graphene can meet all the requirements of energy storage devices for electrode materials. Based on the principle of chemical vapor deposition (CVD), the effects of different growth conditions on the quality of graphene films were investigated and the optimum preparation parameters were obtained. The experimental results show that graphene thickens with the increase of growth time, growth temperature and carbon source concentration at low pressure. The growth conditions of graphene monolayer are as follows: under the condition of constant temperature of 1000 鈩，

本文编号：1962507