SECONDARY BATTERIES – LITHIUM RECHARGEABLE SYSTEMS – LITHIUM-ION | Positive Electrode: Lithium Cobalt Oxide
2009; Elsevier BV; Linguagem: Inglês
10.1016/b978-044452745-5.00194-5
AutoresHajime Arai, Masahiko Hayashi,
Tópico(s)Advanced Battery Technologies Research
ResumoLayered lithium cobalt oxide (LiCoO2) with a cubic close-packed arrangement (O3-LiCoO2) is thermodynamically the most stable of the polymorphs of LiCoO2. Electrochemical lithium extraction from LiCoO2 in nonaqueous media enables the formation of LixCoO2 with a strong oxidizing power and high voltage of over 4 V against a lithium negative electrode. The layered structure of LiCoO2 offers favorable lithium ion diffusion paths, and hence a high rate capability. The phase transition of LixCoO2 together with the voltage profile is described. Reversibility and thermal stability are generally retained as long as the composition range is 0.5⩽x⩽1.0 in LixCoO2. Although cobalt is a scarce and expensive element, LiCoO2 has been widely used as a positive electrode material for lithium-ion secondary batteries because of its high reversibility, relatively high thermal stability, and the established process for its synthesis. Coating technology has been applied to LiCoO2 to enhance its stability. Thin LiCoO2 films are promising electrodes for all-solid-state lithium batteries. The properties of Li1+xCoO2, O2-LiCoO2, Li2Co2O4, and partially substituted materials are also described.
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