CEO of PolyPlus Battery Company, Berkeley, California USA.
By Dr. Steven Visco, CEO of PolyPlus Battery Company, Berkeley, California USA.
In the late 1980’s a number of universities and companies and were actively involved efforts to develop and commercialize rechargeable lithium metal batteries. Unfortunately, the formation of high surface area lithium associated with the inefficient stripping and plating of lithium metal in liquid electrolytes doomed the commercial prospects for these battery systems. Not surprisingly, battery developers looked for alternative solutions for the rechargeable battery market, leading ultimately to the commercial introduction of Li-ion technology in 1991. Although Li-ion battery technology has benefited from steady incremental improvements since that time, the market demand for the next generation of disruptive battery technology remains strong. Over the past several years R&D efforts focused on next generation battery technology have covered a broad spectrum of alternative anodes and cathodes as well as the possibility of all solid-state structures and it is not yet clear which of these strategies will lead to commercial success. With regards to lithium-based technologies, there is little doubt that replacing the carbon anode in Li-ion cells with a lithium metal electrode that exhibits highly efficient cycling and safe behavior would lead to a dramatic increase in energy density (Wh/l and Wh/kg). Attempts to solve the Li metal cycling problem have included the use of ionic liquids, polymer electrolytes, gel polymer electrolytes, and even combinations of ionic liquids with polymer electrolytes, but it is unclear why any of these approaches should fundamentally stop the formation and propagation of lithium dendrites, and to the best of our knowledge, they do not. Polymer electrolytes have insufficient mechanical strength to prevent dendrite growth[1]. Based on a careful analysis of the literature and our own internal research and development on protected lithium electrodes, we believe that the solution to the Li metal dendrite problem lies in the use of dense, highly conductive inorganic membranes. To date, the only commercial examples of high cycle life lithium metal batteries are thin-film cells made through sequential sputter deposition, and these cells demonstrate more than 10,000 cycles to 100% depth of discharge (although at uA/cm2 capacities). In this presentation we will examine a number of development paths for solid-state anodes, as well as the evolution from Li-ion to safe, rechargeable Li metal batteries.
Authors
Steven Visco and Eugene Nimon
References
[1] C. W. Monroe and J. Newman, “The Impact of Elastic Deformation on Deposition Kinetics at Lithium/Polymer Interfaces,” Journal of the Electrochemical Society 152:2 (2005), A396.
Biography
Steven Visco is the Chief Executive Officer, CTO, and founder of PolyPlus Battery Company in Berkeley, California, as well as a Guest Scientist in the Materials Science Division at the Lawrence Berkeley National Laboratory. Steven J. Visco currently holds 113 U.S. patents, more than 200 international patents and has authored over 70 journal articles, as well as books, monographs and other publications. Dr. Visco graduated with a B.S. in Chemistry from the University of Massachusetts in 1977 and received his Ph.D. in Physical Chemistry from Brown University in 1982. Dr. Visco then joined the staff at the Lawrence Berkeley National Laboratory as a Principal Investigator in the Materials Sciences Division in 1984 where his research interests have included advanced batteries and fuel cells. Steven Visco co-founded PolyPlus Battery Company in 1991. In 2013 Dr. Visco was selected by the City of Berkeley for a “Visionary Award” for his work in next generation batteries. Steve also serves on the Technical Advisory the CIC Energigune Institute in Miñano, Spain and was awarded the 2011 International Battery Association Award for “Outstanding Contributions to the Development of Lithium-Air and Lithium-Water Batteries.” PolyPlus Battery Company was selected by TIME magazine for its 50 Best Inventions of 2011 Issue, and was selected for a Gold Edison Award in 2012. In May 2015 Dr. Visco was elected a Fellow of the Electrochemical Society.
