Phase equilibria in acrylonitrile-butadiene copolymer-lithium hexafluoroarsenate (LiAsF6) systems with varying contents of electron donor CdropN groups were studied by X-ray diffraction, optical microscopy, and IR spectroscopy. Fragments of phase diagrams for the SKN-26-LiAsF6, SKN-40-LiAsF6, and SKN-50-5-LiAsF6 systems were constructed in the temperature range 25-60degreesC. A temperature increase to 80degreesC caused thermooxidative destruction of the polymeric matrices. An increase in the content of nitrile groups in copolymers was shown to broaden the homogeneity region of the macromolecular ionic solution.