A number of materials with the composition
Li.sub.1+xNi.sub..alpha.Mn.sub..beta.Co.sub..gamma.M'.sub..delta.O.sub.2--
zF.sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti) for use with rechargeable batteries,
wherein x is between about 0 and 0.3, .alpha. is between about 0.2 and
0.6, .beta. is between about 0.2 and 0.6, .gamma. is between about 0 and
0.3, .delta. is between about 0 and 0.15, and z is between about 0 and
0.2. Adding the above metal and fluorine dopants affects capacity,
impedance, and stability of the layered oxide structure during
electrochemical cycling. Another aspect of the invention includes
materials with the composition
Li.sub.1+xNi.sub..alpha.Co.sub..beta.Mn.sub..gamma.M'.sub..delta.O.sub.yF-
.sub.z (M'=Mg,Zn,Al,Ga,B,Zr,Ti), where the x is between 0 and 0.2, the
.alpha. between 0 and 1, the .beta. between 0 and 1, the .gamma. between
0 and 2, the .delta. between about 0 and about 0.2, the y is between 2
and 4, and the z is between 0 and 0.5.