Abstract: A polymer of formula (I), wherein the nitrogen atoms are coordinated with a lithium atom in 0% to 100% of repeat units in the polymer, and each R1 in each individual repeat unit independently represents a bivalent group, wherein the bivalent groups are, independently from one another, alkylene, arylene, or —CH2—CH2—(O—CH2—CH2)m—, wherein m is an integer of 1 or more, and wherein the alkylene, the arylene, and the —CH2—CH2—(O—CH2—CH2)m— are optionally substituted with one or more halogen atoms. The polymers of the invention can be used as battery electrolytes.

Abstract: The present technology relates to inorganic compounds having an argyrodite-type structure based on an alkali metal obtained by a preparation process comprising a step of grinding the sulfide of the alkali metal, the sulfate of the alkali metal, phosphorus pentasulfide and a halide of the alkali metal. Also described are electrode materials, electrodes, electrolytes comprising said inorganic compound having an argyrodite-type structure and their uses in electrochemical cells, for example, in electrochemical accumulators, particularly in all-solid-state batteries.