TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Material: The electrode active material comprises the composite metal halide ( less than or equal to 10, preferably less than or equal to 5 wt.%). Preferred Method: The contacting is performed in air or in a solution. The method further involves sintering the resultant. The sintering is performed at 0-1000 degrees C for 1-24 hours; and is performed in an inert atmosphere. Preferred Components: The precursor comprises a salt comprising an alkali metal and a salt comprising a metal with an oxidation number of greater than or equal to 2. The salts selected from fluoride salt, chloride salt, bromide salt or iodide salt. The content of the composite metal halogen or its precursor is less than or equal to 10 (preferably less than or equal to 5) wt.% based on the total weight both the core and the composite metal halogen or its precursor. The composite metal halide is AaMeXb (preferably Li2TiF6, Na2TiF6, K2TiF6, Li2ZrF6, Na2ZrF6, K2TiF6, Li3AlF6, Na3AlF6, K3TiF6, Li3FeF6, NaFeF6, Na3FeF6, Na2AlF6, K3AlF6, K3FeF6, K2ZrF6, LixNa2-xTiF6, LiyK1-yTiF6, Li2Zr0.5Ti0.5F6, Li3Al0.5Fe0.5F6, Li3MoF6, Li2MoF6, LiMoF6, or Li3HfF6). The coating layer comprises: at least one element selected from alkali metals; at least one element selected from metals with an oxidation number of greater than or equal to 2; and at least one element selected from halogens. The metal with an oxidation number of greater than or equal to 2 is a metal selected from Al, Fe, Ti, Zr, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, Mo, Ru, La, Hf, Nb, Ge, Ag, W or Si. The composition ratio of halogen element to the metals with an oxidation number of greater than or equal to 2 is 3.5:1 to 6.5:1 in the coating layer. The composition ratio of alkali metal elements to the metals with an oxidation number of greater than or equal to 2 is 0.5:1 to 3.5:1 in the coating layer. The composite metal halide does not intercalate or deintercalate lithium. The thickness of the coating layer is 1 Angstrom to 1 mu m. The core comprises a cathode active material, a lithium transition metal oxide; and an overlithiated lithium transition metal oxide (OLO). The core comprises an anode active material. The core comprises at least one lithium metal, a metal which is alloyable with lithium, a transition metal oxide, a non-transition metal oxide, or a carbonaceous material. The core comprises at least one material selected from Si, Sn, Al, Ge, Pb, Bi, Sb, Si-Y1 alloy, Sn-Y alloy, lithium titanium oxide, vanadium oxide, lithium vanadium oxide, SnO2, SiOx (where x is 0-2), natural graphite, artificial graphite, soft carbon, hard carbon, mesophase pitch carbide, or sintered coke. The coating layer is formed by contacting the composite metal halide containing a metal with an oxidation number of greater than or equal to 2 or its precursor with the core. The precursor of the composite metal halide is sintered. The core compounds are Li(LiaM''1-a)O2+d (II) or Li(LibM''cM'e)O2+d (preferably Lix'Co1-y'MyO2-a'Xa', Lix'Co1-y'-zNiy'Mz'O2-a'X'60, Lix'Mn2-y'MyO4-a'X'60, Lix'Co2-y'MyO4-a'X'60, Lix'M''y'Mz'PO4-a'X'a', pLi2M1O3-(1-p)LiM''O2, or x''Li2M1O3-y''LiM''O2-z''Li1+d''M'2-d''O4).A=metals selected from lithium (Li), sodium (Na), or potassium (K);Me=aluminum (Al), iron (Fe), titanium (Ti), zirconium (Zr), scandium (Sc), vanadium (V), chrome (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo), ruthenium (Ru), lanthanum (La), Hafnium (Hf), Niobium (Nb), germanium (Ge), silver (Ag), tungsten (W), or silicon (Si);X=halo;a=1-3;b=4-6;x=0-2;y=0-1;a, b, p and x''-z''=0-1;e=0-0.1;orb+c+e=1;d=0-0.1;M''=Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Al, Mg, Zr, or B;M'=Mo, W, Ir, Ni, or Mg;x'=0.90-1.1;y'=0-0.9;z'=0-0.5;a'=0-2;y'-z'=0-1;M=Mg, Ca, Sr, Ba, Ti, Zr, Nb, Mo, W, Zn, Al, Si, Ni, Mn, Cr, Fe, Mg, Sr, V or rare-earth elements;X'=O, F, S, or P;orx''+y''+z''=1;d''=0-0.33;M1=Ti, V. Cr, Mn, Fe, Co, Ni, Cu, Al, Mg, Zr and B;Y1=Mg, Co, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Bi, S, Se, Te, and/or Po. EXAMPLE - LiF and AIF3 were mixed at a ratio of about 3:1, and then Li1.1Ni0.35Mn0.41Co0.14O2 with an average diameter of 15 mu m was added and mixed on a mortar. The mixture was heated starting at 0 degrees C and increased in a nitrogen atmosphere, and then the mixture was sintered at 800 degrees C for 12 hours to manufacture a cathode active material including an Li1.1Ni0.35Mn0.41Co0.14O2 core of which a coating layer is formed including Li2AlF6 on its surface.