Improved Performances of LiNi0.8Co0.15Al0.05O2 Material Employing NaAlO2 as a New Aluminum Source

摘要

To prepare a high-performance LiNi0.8Co0.15Al0.05O2 material (LNCA) for Li-ion batteries, a new aluminum source, NaAlO2, is employed in the coprecipitation step for the first time, and the effect of aluminum sources on the performances is systematically go investigated. Different from the traditional preparation process using Al(NO3)(3) as the aluminum source, the preparation process of the Ni0.8Co0.15Al0.05(OH)(2.05) precursor from NaAlO2 is a hydrolysis process, during which the fast precipitation of Al3+ and the formation of a flocculent precipitate can be effectively avoided. As LNCA with uniform element distribution, low cation mixing and well-ordered layered structure is obtained from NaAlO2, which is designed as LNCA-NaAlO2. The characterization and electrochemical measurements show that LNCA-NaAlO2 exhibits significantly improved performances (such as tap density, initial discharge capacity and volumetric energy density, rate performance, cycle performance, electrochemical stability, microstructure stability, and storage stability) compared to the performances of those prepared from Al(NO3)(3) (LNCA-Al(NO3)(3)), indicating that it is an effective strategy to preparing high-performance LNCA employing NaAlO2 as the aluminum source.