Composite Solid Electrolytes

The review describes composite electrolytes based on classical salt matrix phases, and also shows the possibilities of creating composites using simple or complex oxide matrices, where simple substances, salts, simple and complex oxides are used as heterogeneous dopant. The magnitude of the composite effect of electrical conductivity is discussed from the point of view of various theories of its quantitative description. The reasons for the occurrence of the composite effect are summarized. The effect of increasing ionic conductivity is due to the disorder of the surface layer in the intergranular space, amorphization or spreading of the matrix phase or the phase of heterogeneous dopant over the surface of the other phase due to the difference in surface energy, as well as the possibility of joint manifestation of these effects when using complex oxide eutectic composites with treatment above the temperature of the eutectic system.