Manganese Oxides-Based 5V Composite Cathode Materials for Li-Ion Batteries in HEV and PHEV Applications

The rapidly growing market for Plug-In Hybrid Electric Vehicles (PHEVs) represents a new and exciting application for lithium-ion batteries. However, major improvements are desired in specific energy values (>350 Wh/kg), voltage range (>4.8V), and safety. This project will develop a 5V cathode as a composite of three components: (1) a spinel-structured LiMxMn2-xO4 material (M = Ni, Cu, or Cr) to provide electrochemical stability for the cathode; (2) a layered LiMxMn1-xO4 material (M = Ni, Cu, or Cr) as the high-capacity component; and (3) a thin layer of Al2O3 or ZnO, applied as a coating. The Al2O3 or ZnO coating is used to inhibit potential detrimental reactions with the electrolyte at high potentials (>4.6V), which otherwise may occur on an uncoated, highly discharged, spinel-based electrode surface. Following Phase I, the best candidates will be synthesized and scaled up for application in Plug-In Hybrid Electric Vehicles. Commercial Applications and other Benefits as described by the awardee: The technology should contribute to the development of lithium-ion batteries with specific energies as high as 350 Wh/kg. In addition to PHEVs, these battery systems should be highly desirable in the portable electronics market (notebooks, cellular phones, portable medical devices, etc.) and in other consumer and military applications such as portable instruments (testing and medical), power tools, and satellites.