UNS: Engineering of Polymer Electrolytes for Energy Storage

Drexel University, Philadelphia PA

Investigators

Abstract

Lau, 1510888 Looking to the future, energy storage devices will require significant technological leaps to satisfy the increasing demands of the energy economy. Concomitantly, enhanced energy storage solutions will require significant scientific breakthroughs in materials and processes. Focusing on rechargeable lithium ion batteries, miniaturization is anticipated to be an important path forward, especially with the recent advances seen in portable electronics, microelectromechanical systems (MEMS), wireless devices, medical implants, and sensors. This project will study new synthesis and processing strategies for engineering small scale lithium ion batteries. Specifically, adapting smaller microbatteries, particularly as on-board power sources, will require a transformation from the current two-dimensional (2D) planar thin film design to a three-dimensional (3) architecture composed of porous nanostructured materials. This battery redesign project aims at taking advantage of the much larger active surface area to volume and smaller charge transport distance for increasing energy and power density is such miniaturized devices. In addition, materials can display new phenomena at the nanoscale, such as faster electrode processes and lesser electrode strain, compared to bulk behavior. This project aims at increasing energy and power density by utilizing the much larger active surface area to volume and smaller ion transport distance in this miniaturization approach. But, there exist significant knowledge gaps related to finding appropriate all solid state nanoscale electrolytes, viable nanoscale synthesis and processing pathways, and nanoscale ion conduction phenomena amenable to a 3D nano structured design. Thus, the overall objective of this application is to bridge these knowledge gaps to deliver new nanoscale materials, nanoscale synthesis and processing methodologies, and to study nanoscale behavior in such lithium ion batteries. Specifically, the PI has chosen to study polyethylene oxide (PEO) polymers as potential all solid state polymer electrolytes that will be synthesized and conformally coated on the surfaces within mesoporous aperiodic 3D nanostructures. He will apply a liquid-free synthesis and deposition technique developed in his lab that enables ring opening cationic polymerization of ethylene oxide ring monomers in a chemical vapor deposition environment. The specific research aims are to: (1) define the processing space to create conformal coatings of PEO polymers inside 3D porous nanostructured materials; (2) understand the ion conduction behavior of PEO polymers within 3D nanoconfined domains; and (3) obtain the structure-property-processing relationships to create 3D nanostructured lithium ion batteries. Efforts from this work are expected to extend beyond energy storage into the fields of sensors, electrochromics, and biomedicine. Integrated with the research program is an educational thrust that aims to train graduate and undergraduate students as well as engage scientists in nanoscience and nanotechnology related to energy storage. Additionally, high school students will be recruited to participate in independent research through established relationships with area high schools. Minority, underprivileged and underrepresented students will be actively recruited. Outreach to Philadelphia high schools will be made to enhance student awareness and action in energy technologies and social responsibility. Outreach to middle school students through non-profit organizations will be made to motivate science learning.