Chunlei Wang

Title : Bipolar electrochemistry produced graphene for micro supercapacitor

Abstract:

The development of micro-supercapacitors has attracted considerable interest due to the increasing demand for reliable miniaturized energy storage devices. Among all the desired properties of micro-supercapacitors, high power density, and more importantly, rate capability and high-frequency response are crucial for their future applications. It has been demonstrated that electrochemical double-layer capacitors (EDLCs) made of highly oriented vertically graphene structure showed the most promising behavior, for being used at high frequencies. Since now, CVD is the only method that is successfully utilized to produce the desired morphology; however, the limitations related to the fabrication process prohibited the production of micro-supercapacitors based on these materials.

In this study, a modified bipolar electrochemistry (BPE) method has been successfully developed to produce and deposit high quality reduced graphene oxide on a conductive substrate. This method combines the material production and device fabrication in a simple, controllable, cost-efficient, and eco-friendly single-step process. The microstructural study of the deposited material showed the formation of oriented graphene sheets on the substrate. To fabricate the micro-supercapacitor, an interdigitated gold microelectrode arrays was produced by the regular photolithography process and then used as the conductive substrate in the BPE process. The electrochemical study of the fabricated device by cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) confirmed the excellent specific areal capacitance of the device. More importantly, electrochemical impedance spectroscopy (EIS) showed very high-frequency responses, which is promising for AC/DC filter applications. The results will be presented in detail at the conference.

Audience Take Away:

• This talk will inform the audience with a new way of producing high quality graphene.
• Audience dependence on various vendors of graphene can be eliminated since they will be able to synthesize graphene.

Biography:

Chunlei (Peggy) Wang is a full professor in the Mechanical and Materials Engineering Department at Florida International University. She received her MS (1993) and PhD (1997) in Physics from Jilin University (China). Before joining FIU, she held various research positions at Osaka University (1995-2001) and University of California Irvine (2001-2006). At FIU, her group focuses on the development of micro and nanofabrication methods for building novel micro and nanostructures and synthesizing nanomaterials that have unique structures and useful properties for energy and biological applications. She is a recipient of DARPA Young Faculty Award in 2008. FIU faculty award in research and creative activities (2013) and FIU Kauffman Professor Award (2009). She was a co-founder of Carbon Microbattery Corporation (Enevate Corp), a consultant at Intel Lab (2012), and a guest scientist at Max Planck Institute (2012-2013).