Chemically stable solid Li ion conductor of garnet-like crystal structure and Li ion conductivity greater than 3.4.10 ->6 S/cm and stoichiometric composition L(5+x)AxG(3-x)M2O12, where L = Li ion, M = Nb or Ta. An independent claim is included for a method...

Producing oxidic compounds comprises heating mixtures comprising oxides, hydroxides, carbonates and nitrates of lithium and of elements from groups 2-12 together to 600-1200[deg] C in a reaction vessel performing incomplete rotary motions about one axis. P...