Coating Material for Cathode Active Material in Lithium Batteries

A lithium battery comprises cathode active material comprising particles of a transition metal oxide, each particle coated in an ion-conducting material that has an electrochemical stability window against lithium of at least 2.2 V, a lowest electrochemical stability being less than 2.0 V and a highest electrochemical stability being greater than 4.2 V, the ion-conducting material selected from the group consisting of: CsLiC1; CsLiCrF; CsLiDyCl; CsLiErCl; CsLiGdCl; CsLiLuCl; CsLiNdCl; CsLiPrCl; CsLiScCl; CsLiSmCl; CsLiTbCl; CsLiTmCl; CsLiYCl; CsLiCl; CsLiCl; CsLiCl; CsLiCl; CsLiBeF; CsLiCl; KLiZrHOF; KLiCeCl; KLiDyCl; KLiGdCl; KLiLaCl; KLiPrCl; KLiTbCl; KLiDyF; KLiErF; KLiGdF; KLiHoF; KLiLuF; KLiPHOF; KLiTbF; KLiTmF; KLiYF; LiMgCl; LiBOF; LiBOF; LiBeCl; LiBF; LiCaHfF; LiMgCl; LiSiF; LiTa(OF); LiZnCl; LiZrF; LiAlF; LiErCl; LiScCl; LiScF; LiThF; LiYF; LiBePBrO; LiBePClO; LiZrF; LiZrBeF; LiMgPOF; LiAlCl; LiBOF; LiBF; LiGdCl; LiLuF; LiScF; LiTaF; LiThF; LiYF; LiZrTF; NaLiAlF; NaLiAlF; NaLiBeF; NaLiMgPOF; RbLiCeCl; RbLiDyCl; RbLiErCl; RbLiGdCl; RbLiLaCl; RbLiLuCl; RbLiPrCl; RbLiScCl; RbLiTbCl; RbLiYCl; RbLiBeF; RbLiCl; and RbLiF.