激光直写微型RGO/MWCNT/CF平面柔性超级电容器的制备及性能

Fabrication and Capacitance Performance of Laser-machined RGO/MWCNT/CF In-plane Flexible Micro-supercapacitor

将采用改性Hummers法制备的氧化石墨烯与多壁碳纳米管(MWCNT)复合,通过激光直写的方法制备了以棉织物(Cotton fabric,CF)为基底的石墨烯复合碳纳米管的同心圆形织物柔性平面超级电容器(RGO/MWCNT/CF)。通过扫描电子显微镜、X射线衍射和拉曼光谱技术对RGO/MWCNT/CF进行了表征,并对超级电容器的电导率和电化学性能进行了测试。结果表明,电极材料经激光还原后导电率达到了7. 19×10^4S/m,表现出良好的导电性能。以RGO/MWCNT/CF为工作电极、PVA/LiCl凝胶为电解质组装的超级电容器具有良好的电化学性能,在电位窗口为0~1 V、电流密度为40. 8 m A/cm^2时比电容达到24 mF/cm^2,功率密度为61 mW·h/kg,能量密度为1. 22 mW·h/kg,且循环1000次仍能保持92%的比电容。

Micro and flexible supercapacitors are promising energy storage devices that were prerequisite in smart-garment system. However,the electrochemical performance of micro-supercapacitor is lower than that of batteries. Herein,RGO/MWCNT/CF micro-supercapacitor was prepared via laser-machining of graphene oxide( GO) and multi-walled carbon nanotubes( MWCNT) on the cotton fabric( CF). The GO was reduced and MWCNT was fixed on the graphene layer when the laser sculptured the in-plane pattern on the cotton fabric. This nanomaterial shows high electrical conductivity( 7. 19 × 10^4 S/m),attributed to the combined nanomaterials increasing the integrality of the conducting network. The best monolithic supercapacitor exhibited an area capacitance of 24 mF/cm^2 in PVA-LiCl electrolyte( PVA = polyvinyl alcohol). The energy density attained 1. 22 mW · h/kg and the power density reached 61 mW · h/kg. Micro-supercapacitors exhibited remarkably high mechanical fiexibility and showed a good cycling stability,with 92% retention of the specific capacity after 1000 cycles.