M3-MODIFIED LIMN2O4 SPINEL INTERCALATION CATHODES .1. ADMETAL EFFECTSON MORPHOLOGY AND ELECTROCHEMICAL PERFORMANCE()

Low levels of trivalent cations were utilized to stabilize LiMn2O4 spi nel cathode materials against capacity decline during electrochemical cycling. Of the several single-phase products obtained, only those wit h Cr3+ and Ga3+ prevented capacity fade, and only LiCr0.02Mn1.98O4 exh ibited acceptable initial reversible capacity. The external particle m orphology was unchanged by the preparation or the admetal, and the int ernal structures were all converted to cong tou (onion) configurations during product synthesis. Grain size played a surprising role in cath ode performance: <25 mu m material had at least 10% lower capacity tha n larger or as-prepared Cr-doped LiMn2O4.