SBIR Phase I: Modified Ionic Liquid Electrolytes for Low-Cost, High-Energy Li-ion Batteries

Siilion, Inc., Broomfield CO

Investigators

Abstract

This SBIR Phase I project will enable a high-performance, large particle size silicon anode for integration in SiILion's proprietary high energy Li-ion system. While rechargeable lithium-ion batteries (LIBs) have dominated the portable electronics market for nearly a decade, they have failed to gain widespread commercial success in high power and high capacity applications due to material limitations. Demand for a battery providing 400 Wh/kg, 700 Wh/L (almost double the specific energy of current state-of-the art lithium-ion batteries) is growing. Reaching the performance demands of next-generation Li-ion batteries will require breakthroughs in next-generation electrode materials. If successful in enabling its proposed 900 Wh/L technology, SiILion could offer the public an opportunity to own an affordable, safe, environmentally conscious vehicle while also providing safe, high energy batteries for applications ranging from consumer electronics to grid storage. Moreover, SiILion's high energy battery technology has major implications in the aerospace and defense industries, providing a non-flammable battery for vehicular and on-person applications. In the race to develop the next successful Li-ion technology, the U.S. economy stands to gain; SiILion's proposed Li-ion battery system provides an opportunity for the U.S. to own high impact battery technology and reclaim a leadership position in the Li-ion market. Most research aimed towards enabling next-generation electrode materials, both in academia and industry, focuses on expensive material modification. Conversely, SiILion is working to enable low-cost and scalable electrode materials using a new class of electrolyte: room temperature ionic liquids (RTILs). In order to truly realize a low-cost and scalable bulk-type Si anode, the incorporation of larger Si particles needs to be achieved. Micron-scale silicon (Micro-Si) is the ideal anode material for low cost and high capacity, but a full-cell incorporating Micro-Si has never been demonstrated commercially or in academia because of complications stemming from the material's expansion during lithiation. Upon optimizing the micron-Si anode in an RTIL electrolyte, the following areas will be investigated: (1) overall electrode thickness change upon lithiation and delithiation, (2) characterization of electrode mechanism and material morphology throughout cycling, (3) development of full-cells in a coin cell configuration, and (4) development of full-cells in a large-format configurations. This SBIR Phase I project will, for the first time demonstrate a working Micro-Si anode in a Li-ion full-cell, through the optimization of the electrode architecture and its accompanying electrolyte composition.