We report the synthesis and characterization of a series of Co-free, Li-rich Li1+xNi0.5Mn1.5O4 (0<x<1) cathode materials obtained via a low-temperature synthesis method. These materials give high reversible capacities up to 250 mAh/g cycled between 2.4 and 4.9 V vs. Li/Li+, high rate capability and good cycling life. Th cycling stability can be further improved by optimizing morphology, particle size distribution and additional surface coating and proper selection of electrolyte.
Full cell data of these cathode materials in combination with graphite or silicon/carbon composites as anodes demonstrate 15 to 20% higher specific energy compared to reference cells using NCM622 as cathode material, excellent rate capability, better safety and good cycling life.