Surfactant-coassisted sol-gel synthesis to prepare LiNiyMnyCo1-2yO2 with improved electrochemical behavior

Layered LiNi (y) Mn (y) Co1 - 2y O-2 [y = 0.5, 0.45, and 0.4] compounds with interconnected spherical particles are synthesized using a novel surfactant-coassisted sol-gel process. A combination of cetyltrimethyl ammonium bromide as surfactant and citric acid as chelating agent results in the formation of hydrophobically nucleated transparent gel, which upon furnace calcination yields phase pure and growth-controlled spherical particles of LiNi (y) Mn (y) Co1 - 2y O-2 [y = 0.5, 0.45, and 0.4] compounds. The compounds containing Co3+ ions, viz., LiNi0.45Mn0.45 C0.1O2 and LiNi0.4Mn0.4Co0.2O2 cathodes, exhibit good cation ordering and better electrochemical performance than LiNi0.5Mn0.5O2 cathode. The study demonstrates the superiority and suitability of LiNi0.4Mn0.4Co0.2O2 cathode over LiNi0.5Mn0.5O2 and LiNi0.45Mn0.45Co0.1O2 cathodes at 1 C rate and up to 4.6 V limit.