A Quest for Sustainable Energy: From Nanoscale Energy Generators to Green Batteries and Supercapacitors
Authors: El-Kady Maher F. 
Published: July 2021

Batteries run just about everything portable in our lives such as smartphones, tablets, computers, etc. While we have become accustomed to the rapid improvement of portable electronics, the slow development of batteries is holding back technological progress. This has put energy storage research as one of the most explored areas in chemistry and materials science. In this talk, I will discuss innovative techniques for the fabrication of energy-storage devices with new features not possible with current state-of-the-art technology. Several examples will be given, ranging from smaller and more powerful batteries to completely flexible and stretchable energy-storage devices as well as green and biodegradable batteries. Special emphasis will be placed on supercapacitors that are gradually changing our lives in many ways; they are also revolutionizing a breadth of industries including transport, aerospace and consumer electronics. In addition, our work holds promise for a new generation of pacemakers that could save millions of lives by monitoring and controlling the heart rhythms of the patients. While current pacemakers rely on primary batteries for their power, their limited lifespan make replacement surgery unavoidable, putting patients at risk of serious and life-threatening infection. The talk will present ultrathin power sources we have recently developed for harvesting energy from the human body as a promising approach for implantable medical devices that may not need to be replaced during the lifetime of the patient.
The second part of my talk will be dedicated to our recent work on nanogenerators that convert ambient mechanical energy into electricity, offering an alternative for sustainably driving portable electronics. Using 3D extrusion printing, our team developed a prototype nanogenerator to create electricity when it comes into contact with snow. The device could potentially be integrated with solar panels to ensure continuous power supply in areas with frequent snowfall. It is also used as a smartwatch for tracking winter sports, such as skiing, to more precisely assess and improve an athlete’s performance when running, walking or jumping. We utilized a similar technology for designing and building an electronic skin (e-skin) with functionalities and mechanical properties that mimic the natural skin. Unlike current research in this area where tethering to a large battery unit seems inevitable, the new e-skin contains integrated network of energy efficient sensors that create their own charge by touching the skin. This technology can be used to monitor vital signs and chronic medical conditions and may have great implications in robotics, prosthetics, and human-computer interface.
These discoveries were made possible through the development of new functional nanomaterials with interesting and potentially useful characteristics such as optical, structural and electrochemical properties. At the forefront of these materials is graphene that was once established as the thinnest, strongest and most conductive material and today it continues to attract much attention in the scientific community and triggers significant industrial interest. The last part of my talk will discuss the efforts our team is taking to lead the transition of graphene technology from the lab to the marketplace through a UCLA spinoff known as Nanotech Energy, Inc. After 6 years of development, current production capacity has reached one metric tons per year, which catalyzed our ability to transform various graphene discoveries into commercial products, with the very first demonstrations in EMI shielding materials, printed electronics and more powerful batteries and supercapacitors.

Figure 1