Compounds based on an element from the boron group, and use thereof in electrolyte compositions

A compound of Formula I, II, or III, and/or its salts:

• wherein:
• M is an atom selected from the elements of column 13 (Group IIIA) of the periodic table of the elements, for example, a boron, aluminum, gallium, indium or thallium atom, for example a boron, aluminum, gallium or indium atom, or a boron or aluminum atom;
• X is independently selected from O, S, NH, NR, or a C(O)O or S(O)2O group, wherein said group is attached to M by an oxygen atom;
• R is independently selected from substituted or unsubstituted, linear or branched alkyl, cycloalkyl and aryl groups, or 2 or 3 R groups combined with X radicals attached thereto form a 5 to 7 membered ring comprising M, or a bicyclic group having from 7 to 10 members comprising M, and/or at most one XR is a hydroxyl group;
• R1 is independently selected from substituted or unsubstituted, linear or branched alkyl, cycloalkyl and aryl groups;
• and
• A+ is a metallic cation or a cation of an organic base, and where the total molar ratio of A+ relative to the rest of the molecule is adjusted to achieve electroneutrality.