Dr. Karim Zaghib
Karim Zaghib obtained his MS in 1987 and his PhD in 1990, both in electrochemistry from the Institut National Polytechnique de Grenoble , he received the HDR (Habilitation à Diriger la Recherche) in materials science from the Université de Pierre et Marie Curie, Paris, France. Following his research in Japan, Dr Zaghib joined Hydro-Quebec’s ACEP project where he was instrumental in introducing Li-ion technology to the company in 1995. Dr. Zaghib is currently Administrator of the CSE (Conversion and Storage of Energy Department) at the Institute de recherche d’Hydro-Québec in Varennes, Quebec, Canada. Dr. Zaghib is the recipient of the International Electric Research Exchange (IERE) Research Award (2008) in Iguaçu, Brazil, the International Battery Association (IBA) Research Award in January 2010 and Electrochemical Society Energy Division Research award, April 2010.
Many challenging problem must be resolved for integration of safe Li-ion batteries for automotive transportation. The combination of lithium nano-titanate oxide (Li4Ti5O12) anode and lithium iron phosphate (LiFePO4) cathode is a leading candidate for this application. This combination of electrode materials provides a high degree of safety, long cycle life and rapid charge in 5 minutes.The advantages of Li4Ti5O12 are high stable structure without passivation, flat voltage profile of 1.5 V, high safety and low cost. The electrochemical investigation was carried out using 18650 cell with standard organic electrolyte, and the cell demonstrated a remarkable cycle life (see Fig.1). A very stable discharge capacity was obtained at a 5C discharge rate (12 minutes) and 15C charge rate (4 minutes). The capacity remained almost constant at 850 mAh/g for approximately 30,000 cycles at 100% DOD [1]. Security tests was performed on the 18650 cell in the charged state after 30,000 cycles. The crush test (see Fig 2) showed a maximum temperature of 72°C. The nail penetration test revealed that the cell reached a maximum temperature of 103°C, with a small amount of electrolyte escaping from the cell. Finally, a short-circuit test showed a maximum temperature of 63°C. For all three tests no smoke, no flames and no explosion were observed.Because of these significant and promising results, PHET (Taiwan) developed a unique system of protection for EV battery packs consisting of 18650 cells. The patented DOSBAS® safe battery system (see Fig. 3) will protect each cell in the system individually by serially connected quick-blown fuse [2]. [1] A. Guerfi, J. Power Sources., 195, p.851 (2010).[2] Peijen Wang and Donald P.H. Wu, presented at EVS24, Stavanger, Norway, May 13-16, 2009.