Nanocomposite High Voltage Cathode Materials for Li-Ion Cells

The performance of state-of-the-art Li-ion batteries does not meet the requirements of Plug-In Hybrid Electric Vehicles (PHEVs) with respect to energy density and cycle life. While the energy density can be increased by using high voltage (i.e., > 4.8 V) cathode materials, organic liquid electrolytes start to degrade at and above 5V. In particular, there are deleterious interfacial reactions between the cathode particles and the electrolyte, which lead to poor cycle life. The conventional practice of mitigating cathode-electrolyte reactions is to coat the surface of the cathode with an inert material, such as aluminum oxide. Such strategies have met with limited success due to the poor ionic and electrical conductivity of the surface coating. This project will develop a new class of nanocomposite cathode materials. The unique composition and morphology of the cathode particles is expected to effectively prevent the reaction between the cathode material and electrolyte, thereby realizing the goals of high energy density and long cycle life. Commercial Applications and other Benefits as described by the awardee The proposed Li-ion cathode material is expected to increase the energy density and cycle life greatly, and meet future PHEV application requirements. High-energy-density, long-cycle-life Li-ion batteries also should find use in many consumer electronic products, such as cellular phones, laptop computers, and digital cameras.