Surface-segregated, high-voltage spinel LiMn_(1.5)Ni _(0.42)Ga_(0.08)O_4 cathodes with superior high-temperature cyclability for lithium-ion batteries

摘要

The substitution of a small amount of Ga in the high-voltage spinel cathode LiMn_(1.5)Ni_(0.42)Ga_(0.08)O_4 leads to superior cyclability at room temperature and 55 °C along with higher rate capability with conventional electrolytes compared to that found with the LiMn_(1.5)Ni_(0.5)O_4 cathode. The superior performance is attributed to the segregation of the inert Ga~(3+) ions to the surface during the synthesis process, providing a robust, more stable interface with the electrolyte at the high operating voltage (~ 4.7 V), along with the stabilization of the spinel structure with a disordering of the cations in the octahedral sites.