A solid nanocomposite electrolyte material comprising a mesoporous dielectric material comprising a plurality of interconnected pores and an electrolyte layer covering inner surfaces of the mesoporous dielectric material. The electrolyte layer comprises: a first layer comprising a first dipolar compound or a first ionic compound, the first dipolar or ionic compound comprising a first pole of a first polarity and a second pole of a second polarity opposite to the first polarity, wherein the first layer is adsorbed on the inner surfaces with the first pole facing the inner surfaces; and a second layer covering the first layer, the second layer comprising a second ionic compound or a salt comprising first ions of the first polarity and second ions of the second polarity, wherein the first ions of the ionic compound or salt are bound to the first layer.