Synthesis and performance of LiMnO₂ as cathodes for Li-ion batteries

Abstract

Two structure types of LiMnO₂ were synthesized by sol-gel method and ion-exchange method respectively. The results indicate that orthorhombic phase LiMnO₂ is more stable than layered LiMnO₂, o-LiMnO₂ can be synthesized directly by sol-gel methods followed by heat-treated in argon, but layered LiMnO₂ was obtained only by indirect methods such as ion-exchange method. In this paper, we first synthesized layered NaMnO₂ by the sol-gel method, and then obtained layered LiMnO₂ by the ion-exchange method. The phase, constitution, chemical composition, and images of the products were tested by XRD, AAS (atomic absorption spectroscopy) and SEM. The electrochemical performances of the two structural types of LiMnO₂ are obviously different during the initial few cycles, but later they both have a good capacity-retaining ability. The capacity of layered structure LiMnO₂ is higher than that of o-LiMnO₂.

Keywords

orthorhombic LiMnO₂ / layered LiMnO₂ / synthesis / cathodes materials / Li-ion batteries

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