It is now well established that the calendar life and cycle life of Li and Li-ion cells and batteries is highly dependent upon the secondary reactions that occur between the electrodes and the cell electrolyte. These reactions are often referred to as parasitic reactions, as they generally result in the loss of reversible lithium from the cell. It is now common to include a number of electrolyte additives to the cell’s primary electrolyte in order to improve the solid electrolyte interface (SEI) that is generally regarded as being critical for providing passivation against these parasitic reactions. Long-term cycling and exposure to extraordinary temperatures have typically been employed to determine the effect of parasitic reactions and effectiveness of electrolyte additives. Techniques that can rapidly provide fundamental information on cell parasitic reactions and the effect of electrolyte chemistry in controlling the parasitic reactions are therefore of considerable value.
The use of isothermal heat flow measurements combined with high precision coulometry is referred to as electrochemical calorimetry. This presentation will explain how this methodology can be very useful in discriminating the impact of electrolyte chemistry, active electrode materials, and voltage cycling conditions on the calendar and cycle life characteristics of Li-ion cells.
About the Speaker
Larry received a PhD in Physical Chemistry from the University of Illinois (Chicago). After a post-doctoral appointment at Argonne National Labs he joined 3M in 1982. After several assignments in technology areas involving electrochemistry and electrochemical engineering, in 1993 Larry became involved with 3M’s entry into the United States Advanced Battery Consortium (USABC). This project involved the development of a 30kWh polymer electrolyte battery. The consortium was composed of 3M as the prime contractor, Hydro-Quebec and Argonne National Laboratory as co-partners. In 1996 he started an internal 3M project in Lithium ion chemistry. Larry is currently one of the founding members of the experimental consulting firm Cyclikal which provides unique analytic experimental techniques for lithium battery technologies.