Mokhtarnejad Mahshid, Ribeiro Erick L, Mukherjee Dibyendu, Khomami Bamin
Department of Chemical & Biomolecular Engineering, University of Tennessee Knoxville Tennessee 37996 USA
Material Research and Innovation Laboratory (MRAIL), University of Tennessee Knoxville Tennessee 37996 USA.
RSC Adv. 2022 Jun 13;12(27):17321-17329. doi: 10.1039/d2ra02009b. eCollection 2022 Jun 7.
In this study hybrid nanocomposites (HNCs) based on manganese oxides (MnO /MnO) and reduced graphene oxide (rGO) are synthesized as active electrodes for energy storage devices. Comprehensive structural characterizations demonstrate that the active material is composed of MnO /MnO nanorods and nanoparticles embedded in rGO nanosheets. The development of such novel structures is facilitated by the extreme synthesis conditions (high temperatures and pressures) of the liquid-confined plasma plume present in the Laser Ablation Synthesis in Solution (LASiS) technique. Specifically, functional characterizations demonstrate that the performance of the active layer is highly correlated with the MnO /MnO to rGO ratio and the morphology of MnO /MnO nanostructures in HNCs. To that end, active layer inks comprising HNC samples prepared under optimal laser ablation time windows, when interfaced with a percolated conductive network of electronic grade graphene and carbon nanofibers (CNFs) mixture, indicate superior supercapacitance for functional electrodes fabricated sequential inkjet printing of the substrate, current collector layer, active material layer, and gel polymer electrolyte layer. Electrochemical characterizations unequivocally reveal that the electrode with the LASiS synthesized MnO /MnO-rGO composite exhibits significantly higher specific capacitance compared to the ones produced with commercially available MnO-graphene NCs. Moreover, the galvanostatic charge-discharge (GCD) experiments with the LASiS synthesized HNCs show a significantly larger charge storage capacity (325 F g) in comparison to NCs synthesized with commercially available MnO-graphene (189 F g). Overall, this study has paved the way for use of LASiS-based synthesized functional material in combination with additive manufacturing techniques for all-printed electronics with superior performance.
在本研究中，基于氧化锰（MnO /MnO）和还原氧化石墨烯（rGO）的混合纳米复合材料（HNCs）被合成用作储能设备的活性电极。综合结构表征表明，活性材料由嵌入rGO纳米片中的MnO /MnO纳米棒和纳米颗粒组成。溶液激光烧蚀合成（LASiS）技术中存在的液限等离子体羽流的极端合成条件（高温和高压）促进了这种新型结构的形成。具体而言，功能表征表明，活性层的性能与HNCs中MnO /MnO与rGO的比例以及MnO /MnO纳米结构的形态高度相关。为此，当与电子级石墨烯和碳纳米纤维（CNF）混合物的渗流导电网络相接时，包含在最佳激光烧蚀时间窗口下制备的HNC样品的活性层墨水，表明通过依次喷墨打印基板、集流体层、活性材料层和凝胶聚合物电解质层制造的功能电极具有优异的超级电容。电化学表征明确显示，与市售MnO-石墨烯NCs制备的电极相比，采用LASiS合成的MnO /MnO-rGO复合材料的电极表现出明显更高的比电容。此外，使用LASiS合成的HNCs进行的恒电流充放电（GCD）实验表明，与市售MnO-石墨烯合成的NCs相比，其电荷存储容量显著更大（325 F g）。总体而言，本研究为将基于LASiS合成的功能材料与增材制造技术结合用于具有卓越性能的全印刷电子产品铺平了道路。
