Triggered Solutions for Longevity and Safety in Lithium Ion Batteries
Dr. Susan Odom
The Beckman Institute at the University of Illinois
Friday, May 21, 2010 at 10:00am
Conference Room, Spindletop Research Bldg.
UK Center for Applied Energy Research
Core-shell microcapsules have been used to encapsulate suspensions of conductive particles, which can be released upon mechanical rupture of the microcapsule shell wall. In several cases, we have demonstrated the partial to full recovery of electrical conductivity in gold lines with small gaps, modeling crack damage. These capsule systems may be useful in restoring conductivity in mechanically damaged circuits. Mismatches in the thermal expansion coefficients of circuit components and packaging can result in crack damage, which is a major cause of failure of electronic circuitry. It is possible that mechanical force may lead to the release of conductive particles, thus restoring conductivity to a damaged site.
In addition to extending the lifetimes of electronic circuits, we are also interested in improving the performance and safety of lithium ion batteries. While lithium ion batteries are of great interest due to their large rates of discharge, the potential for catastrophic failure makes them impractical for large-scale consumer electronics such as hybrid electric vehicles (HEVs). To prevent overcharge and subsequent thermal runaway, costly circuitry is needed. Additionally, lifetimes of lithium ion batteries are limited due to the high reactivity of the electrodes with the electrolyte. This presentation focuses on the incorporation of redox shuttles and additives into the electrolyte for protection during overcharge and for life extension of high voltage cathode materials. Additionally, we have begun the exploration of using microcapsules for the stimuli-induced delivery of healing materials and for the shutdown of unsafely operating batteries.