Overcoming the chemical instability on exposure to air of Ni-rich layered oxide cathodes by coating with spinel LiMn1.9Al0.1O4

To overcome the chemical instability on exposure to air of Ni-rich materials, a heterostructure composed of a Ni-rich layered oxide core and a Mn-rich LiMn_1.9Al_0.1O₄ shell is explored. The spinel coating alleviates the chemical instability leading to superior capacity retention even after air-storage.