RII Track-4: Developing and Investigating Organic-Inorganic Hybrid Ultrathin Solid Electrolytes with NREL for Lithium Ion Batteries

University Of Louisiana At Lafayette, Lafayette LA

Investigators

Abstract

Nontechnical Description As the market for lithium ion batteries (LIBs) keeps expanding, the importance of battery reliability and safety continues to rise. Commercially used organic liquid electrolytes in LIBs remain a huge safety issue due to their high volatility and flammability. Solid-state electrolytes have attracted great attention as the potential replacement due to their nonflammability, leakproof feature, and resistance to damage caused by dendrite growth. There are two main types of solid electrolytes with complementary properties: solid polymer electrolytes (SPE) and inorganic solid ceramic electrolytes (ISE). This project plans to develop ultrathin ISE/SPE hybrid electrolyte films with laminated bilayer configuration and to study their ISE/SPE interface properties and how these properties influence lithium ion transport and conductivity. The outcomes of this project will greatly advance the knowledge of design and fabrication of solid electrolytes with nanoscale engineered structures and properties for safer LIBs. The training and hands-on experience on cutting-edge technologies and the collaborations established via this program will directly benefit the PI?s continuing research plan on hybrid electrolytes and greatly enhance the research capacity of UL Lafayette. Technical Description SPE have the advantages of simple fabrication process and good flexibility but are inhibited by low ionic conductivity, low thermal stability, and poor oxidation resistivity. ISE have relatively high ionic conductivity and high thermal stability but very low flexibility. Given the complementary properties of SPE and ISE, there have been prior efforts to develop SPE and ISE composite electrolytes with either filler in bulk structure or ISE/SPE laminated multi-layer configuration. It has been found that SPE/ISE interface properties are key influencers of the lithium ion transfer path and conductivity. A good understanding of ISE/SPE interfaces behavior from this work will provide guidance on the design and development of solid hybrid electrolytes materials for practical LIBs application. In this project, a laminated bilayer configuration with one large interface area will be used as a model for the ISE/SPE electrolyte interface study since filler-bulk type electrolytes have too many complicated interface interactions to fulfill the purpose. Two other dominant factors that impact electrolyte performance include film thickness and film evenness. This project will utilize a unique combination of two technical fabrication processes (air-controlled electrospray and magnetron sputtering) that not only significantly lowers the electrolyte film thickness and improves film evenness, but also allows the flexibility to prepare different types of solid electrolytes based on the application?s specific need, such as directly deposited solid electrolyte on electrodes (particularly important for 3D batteries) or free-standing thin electrolyte films. Results and scientific discoveries from this project are of significant meaning for both fundamental knowledge advancement and applied technology development. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.