Na-rich electrolyte compositions provided herein can be used in a variety of devices, such as sodium ionic batteries, capacitors and other electrochemical devices. Na-rich electrolyte compositions provided herein can have a chemical formula of Na3OX, Na3SX, Na (3-delta) M delta / 2OX and Na (3-delta) M delta / 2SX wherein 0 ;lt; delta & lt; 0.8, wherein X is a monovalent anion selected from fluoride, chloride, bromide, iodide, H-, CN-, BF4-, BH4-, ClO4-, CH3-, NO2-, NH2- and mixtures thereof, and wherein M is a divalent metal selected from the group consisting of magnesium, calcium, barium, strontium and mixtures thereof. Na-rich electrolyte compositions provided herein can have a chemical formula of Na (3-delta) M delta / 3OX and / or Na (3-delta) M delta / 3SX; wherein 0 & lt;delta & lt; 0.5, wherein M is a trivalent cation M+3, and wherein X is selected from fluoride, chloride, bromide, iodide, H-, CN-, BF4-, BH4-, ClO4-, CH3-, NO2-, NH2- and mixtures thereof. Synthesis and processing methods of NaRAP compositions for battery, capacitor, and other electrochemical applications are also provided.