A compound has the formula Li4−xB7−yMyO12−zClw, wherein Li, O, and Cl vacancies are allowed and M is either a one-way, two-way or three-way combination of the following species: Al3+, Fe3+, B3+, La3+, Y3+, Mo3+, Be2+, Si4+, Cr4+, As3+, Mn2+, V2+, Co2+, Ge2+, Fe2+, Mo4+, Mo6+, As3−, Ti2+, P5+, As0+, and wherein 0≤x<2, 0<y<6, 0≤z<1, and 0<w<2 either satisfy a charge balance mechanism with their respective defect site B3+, Li+, O2−, or Cl−, or satisfy any combination that maintains
charge neutrality of the compound, and wherein when M comprises Al3+, M is a two-way or three-way combination. A
glass ceramic composition includes the compound. A
lithium ion battery includes a
solid state ionic conductor, wherein the
solid state ionic conductor includes the compound.