Amanda Doucett, a student from RIT, was selected as the winner of NY-BEST’s Student Poster contest held in conjunction with NY-BEST’s Energy Storage Technology Conference in Syracuse, New York, on September 25th, 2013. The Conference featured a keynote address from Dr. Cheryl Martin, Deputy Director of ARPA-E, as well as panel discussions from leading researchers and technology experts. A student poster contest, featuring 35 posters by graduate and post-doctorate students from across New York State, capped off the day’s events. Ms. Doucette’s poster, Thermal Stability and Safety of LiNi0.8Co0.15Al0.05O2 (NCA) Cathodes with Varying Conductive Additives, was selected as the winning poster by conference attendees. Second and third prizes were awarded respectively to Benjamin Richards from Cornell University and Jian Liu from Binghamton University. NY-BEST thanks all speakers, students and attendees for your on-going support and participation!
Amanda Doucett Poster Summary: There is a need for better performing and safer energy storage solutions for electronics, electric vehicles, and other portable power applications. Lithium ion batteries have become a prevalent energy storage technology to meet today’s requirements due to a high power and energy density that allows for lighter, thinner, and longer lasting batteries. However, safety remains a major concern for lithium ion batteries due to the potential for thermal runaway. Thermal runaway is primarily caused by overcharged cathodes releasing oxygen upon heating which, when combined with a flammable electrolyte, results in a continuous exothermic reaction. Improving battery materials and electrode design to optimize performance and stability is inherent to enabling further lithium ion battery adoption. Conductive additives provide a percolation network within cathode composites to enhance electrochemical performance, but the effect on thermal stability of the electrode is not well understood. This work compares conventional conductive additives such as carbon black and vapor grown carbon fiber (VGCF) to single-walled carbon nanotubes in LiNiCoAlO2 (NCA) cathode composites as a function of weight loading to investigate the impacts on electrochemical performance and safety. Scanning electron microscopy and conductivity measurements were used to characterize electrodes and quantify the percolation threshold for each material. Differential scanning calorimetry (DSC) was used to measure the intensity of the exothermic release of the electrode and the temperature at which the reaction occurs. These results have implications towards the nature of the thermal runaway reaction, and can be directly correlated to overall battery safety.