Synthesis and Electrochemistry of LiNi x Mn2 − x O 4

摘要: LiNi{sub x}Mn{sub 2{minus}x}O{sub 4} has been synthesized using sol-gel and solid-state methods for 0 < x 0.5. The electrochemical behavior of the samples was studied in Li/LiNi{sub cells. When = 0, capacity Li/LiMn{sub 2}O{sub cells appears at 4.1 V. As increases, V plateau decreases as 1-2x Li per formula unit, a new 4.7 appears. increases 2x so that total is constant. This taken evidence oxidation state Ni these +2. related to Mn{sup 3+} 4{minus}} Ni{sup 2+} 4+}. effect synthesis temperature, atmosphere, cooling rate on structure properties 0.5}Mn{sub 1.5}O{sub also made by method. heating gels temperatures below 600 C air are generally oxygen deficient, leading Mn states significantly less than 4.more » heated above 650 suffer due disproportionation into with 0.5 Li{sub z}Ni{sup {minus}z}O z {approx} 0.2, which occurs about C. Pure materials can be extended heatings near or slowly higher temperatures. demonstrated good reversible excess 100 mAh/g tens cycles.« less