SBIR-STTR Award

The broader impact/commercial potential of this project centers on furthering scientific understanding of degradation in electrochemical energy storage. The project will explore technology that will enable the large-scale transfer of a key laboratory-proven diagnostic tool from the lab to the field. This tool, called electrochemical impedance spectroscopy (EIS), is a noninvasive assessment of the internal state of a battery. In contrast to current interest-group-initiated, crowd-sourced qualitative research efforts, EIS would enable the collection and analysis of an unprecedented amount of real-time quantitative data to further scientific understanding of electrochemical lifetime and degradation factors of in applications ranging from electric vehicles to grid and building storage. Highly publicized battery pack failures have increased skepticism of electrochemical energy storage in the public eye, and large-scale scientific studies could aid in faster technological improvements to increase widespread adoption of electrochemical energy storage as the U.S. seeks to improve energy independence, efficiency, and security. This Small Business Innovation Research (SBIR) Phase I project addresses the need to innovate on current battery management methods that force battery system overdesign and power/energy underutilization by introducing a platform to enable diagnosis and correction of inherent cell-to-cell imbalances in electric vehicles to improve battery pack performance, reliability, and safety. Specifically, this work deploys electrochemical impedance spectroscopy in a distributed power electronics platform to provide a new toolset for real-time diagnostics and the improved extraction of important information to aid in the determination of battery cell state of charge and state of health. The goal of Phase I Research is to demonstrate efficient and cost-effective scalability of this power-electronics-based EIS. A proof-of-concept prototype has been verified on small-capacity cells, but a commercial solution will need to manage large-capacity cells with much lower impedance which presents control system and EIS accuracy technical challenges. A power converter and accompanying control system will first be developed to meet target specifications, followed by a demonstration board to demonstrate EIS and power management for a number of series-connected cells.

The broader impact/commercial potential of this project will be in promoting clean energy technologies. More than half of the United States? greenhouse gas emissions come from transportation and electricity production. Lithium-ion batteries are a promising technology to facilitate the adoption of electric vehicles and renewable power generation that drastically reduce greenhouse gas emission. However, the high cost of lithium-ion batteries threatens the commercial viability of clean technologies. This Phase II project will develop manufacturing process technologies that reduce the capital and operating costs of the most expensive step in lithium-ion battery manufacturing. Low-cost batteries will push electric vehicles towards widespread commercial adoption. Electrification of mass-transit buses will improve urban air quality, especially for the low-income population located near bus depots. Large-scale battery systems enabled by low-cost batteries will turn renewable power generation such as solar and wind from periodic energy sources into on-demand energy sources to alleviate our dependence on fossil-fuels. This Phase II project will help lithium-ion batteries become a key technology in the successful departure from oil dependence, combat of climate change, and the United States? energy security.This Small Business Innovation Research (SBIR) Phase 2 project addresses the need for deeper understanding of the fundamental science behind the solid electrolyte interphase (SEI) layer. SEI layer quality is a key determinant of long-term battery reliability, performance, and safety, but the underlying electrochemistry that governs SEI composition and evolution remains poorly understood. This Phase II project will develop novel, in-situ diagnostics to directly measure the evolution, performance, and characteristics of the SEI layer as it is formed during lithium-ion battery manufacturing. Deeper insight into the complex morphology of the SEI layer will advance much-needed industry knowledge of battery performance, quality, and longevity. Additionally, there is a sizeable body of work in modeling the degradation of batteries throughout their lifecycle. With improved cell-level traceability, the manufacturing insights enabled by this Phase II project will expand the current understanding of the ?ideal battery? at the beginning of life and complement ongoing work on how batteries degrade over time. This insight opens the door for quality control in battery manufacturing based on more direct quality metrics such as longevity and reliability rather than indirect metrics such as beginning of life capacity.