Composite, Nanoparticle-Based Anode Materials for Li-Ion Batteries Applied in Hybrid Electric Vehicles (HEVs)

Lithium-ion batteries are promising energy storage devices for hybrid and electric vehicles, providing high specific energy (approximately 150 Wh/kg), energy density (approximately 400 Wh/L), and long cycle life (greater than 15 years). However, these applications require further increases in energy density and improved low-temperature (less than ¿10 degrees C) performance. Silicon-based anodes are inexpensive, environmentally benign, and offer excellent theoretical capacity values (approximately 4000 mAh/g), with an energy density exceeding 500 Wh/L for the complete battery. However, the cycling-related expansion of silicon particles causes them to fracture and lose electrical contact with the current collector, thereby limiting the cycle life of the battery. This project will develop a carbon/nano-silicon composite anode with improved energy density and the cycle life of silicon. Phase I will focus on developing and screening advanced composite anode candidates for application in lithium-ion batteries. Phase II will take the successful anode candidates(s) and scale-up production for the successful anode candidate(s) and optimize an existing lithium-ion battery to accommodate the novel advanced material. Commercial Applications and other Benefits as described by the awardee: Inexpensive, safe and environmentally benign lithium-ion cells, with high energy density and high-rate capability, should benefit the electric vehicle (EV) and hybrid electric vehicle (HEV) markets. Other niche markets include military man pack batteries and charging sources, aircraft applications, and specialized industrial applications.