So2-based electrolyte for a rechargeable battery cell and rechargeable battery cell

An SO2-based electrolyte for a rechargeable battery cell, comprising a first conducting salt of formula (I):

• wherein;
• m is a metal selected from the group consisting of alkali metals, alkali earth metals, metals from Group 12 of the periodic table of elements, and aluminum;
• x is an integer from 1 to 3;
• the substituents R1 and R2 are selected, independently of one another, from the group consisting of a halogen atom, a hydroxyl group, an —OR5 chemical group and a chelating ligand, which is collectively formed by at least two of the substituents R1, R2, R3 and R4 and is coordinated to Z;
• the substituent R3 is selected from the group consisting of a hydroxyl group, an —OR5 chemical group and a chelating ligand, which is collectively formed by at least two of the substituents R1, R2, R3 and R4 and is coordinated to Z;
• the substituent R4 is selected from the group consisting of a halogen atom, a hydroxyl group and a chelating ligand, which is collectively formed by at least two of the substituents R2, R3 and R4 and is coordinated to Z;
• the substituent R5 is selected from the group consisting of C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C3-C10 cycloalkyl, C6-C14 aryl and C5-C14 heteroaryl;
• and
• Z is aluminum or boron.