Solid State Ionics, Vol.76, No.3-4, 215-220, 1995
New Solid Electrolytes and Mixed Conductors - Li(3+x)Cr(1-X)M(X)O(4)M=ge, Ti
New Li+ ion conducting solid solutions with gamma-LISICON type structure have been found in the system Li3+xCr1-xGexO4 for 0.35 < x < 0.92. Conductivity increases with x; at x = 0.90, sigma (bulk) similar or equal to 1.4X 10(-5) S cm(-1) at 27 degrees C rising to 0.044 S cm(-1) at 300 degrees C; E(a)=0.51 eV. Similar gamma solid solutions form in the Ti system, Li3+xCr1-xTixO4:0.5 < x < 0.8; however, these are mixed Li+ ion and electronic conductors. Both systems are unusual in containing Cr in the +V oxidation state.