This issue's special focus is on advanced lithium ionbatteries for hybrid electric vehicle applications. The four articlesaddressing this area explore the modeling of lithium ion batterychemistries; the use of advanced diagnostic methods to study the physicsand chemistry of battery materials; a laboratory for advanced batterytesting; and approaches for improving battery safety. EETD's research isfunded by the Department of Energy's BATT (Batteries for AdvancedTransportation Technologies) program, FreedomCar and Vehicle TechnologiesProgram.