Atomic layer deposition of stable lithium ion conductive interfacial layer for stable cathode cycling

A method of forming a coated cathode material, comprising:

• providing a cathode active material having a high nickel content of at least about 75% by atomic ratio, wherein the cathode active material is comprised of nickel-containing particles each having a size of about ten microns or less;
• and
• forming, via atomic layer deposition, an interfacial layer coating the nickel-containing particles of the cathode active material,
• wherein the interfacial layer includes a lithium-containing fluoride, wherein the lithium-containing fluoride contains lithium and at least one additional metal different from lithium, and wherein the interfacial layer is configured to provide an interface between the cathode active material having high nickel content and an electrolyte.