SPINEL-BASED CATHODE MATERIALS FOR HIGH ENERGY/POWER LITHIUM ION BATTERIES

Abstract

There are urgent needs to develop lithium-ion batteries with high energy/power density for applications in hybrid-electric and electric vehicles. The limited energy/power density of current cathode materials becomes one of the main obstacles of their widespread adoption as well as the cost and safety concerns. In this regard, spinel oxide has attracted particular attention because of its high operating voltage with 3-dimensional lithium diffusion pathway. Moreover, this manganese-rich material is inexpensive, stable and environmentally friendly. However, the application of spinel materials in high energy/power devices has so far been hindered since they encounter poor rate capability and cycle stability. The objective of the present study is therefore focused on developing suitable spinel cathodes with enhanced electrochemical performance. To achieve this objective, morphological modification, surface coating, cation doping and nanodomain engineering were introduced and a series of spinel-based cathode materials with excellent rate capability and cycle stability have been successfully developed.