Nano-Structured Carbon/Silicon Composite for High Energy, Long Cycle Life Lithium-Ion Batteries

Battery-powered electric vehicles (EVs) require energy storage devices with high specific energy, but currently available lithium-ion systems can not meet the energy and power goals for EVs. Lithium-ion cells are needed that provide at least 150 Wh/kg, 230 Wh/l, 300 W/kg, and 460 W/l; have a life of 1000 cycles at 80 percent depth of discharge; have a calendar life of at least 10 years; and are made with materials costing less than $10/kg. To meet this need, this project will develop a high-capacity, long-cycle-life, nanostructured, silicon/carbon composite anode material, made using low cost materials and processes. In Phase I, the synthesis of the nano-scaled silicon material was demonstrated. A model was developed to demonstrate the potential impact of nanostructured silicon/carbon composite anodes on Li-ion cell energy; it was shown that the composite could enable the above-listed performance targets to be attained. In Phase II, the composite of nano-scaled silicon with carbon will be developed, and its performance will be demonstrated in scaled-up Li-ion batteries. Commercial Applications and Other Benefits as described by the awardee: The proposed low cost material should have broad commercial applicability in small portable power lithium-ion batteries for consumer electronics and power tools, as well as in large lithium-ion batteries for electric vehicles and hybrid electric vehicles.