This is an expert that has made major scientific contributions in primary and secondary lithium batteries, lithium-ion batteries, liquid and polymer electrolytes, polymer batteries, rechargeable sodium batteries, and battery materials synthesis and characterization. His pioneering work in the 1980`s on organic liquid electrolytes and secondary lithium batteries, and in the 1990`s on polymer electrolytes has contributed significantly to the development of rechargeable lithium and lithium-ion battery technologies. He and his colleagues were one of the first research groups to develop a practical rechargeable lithium battery in the early nineteen eighties. His recent efforts have involved materials research and engineering development of large lithium-ion batteries for aerospace and stationary applications, safety studies and applications of lithium-ion batteries, and battery technology overview and assessment studies.