Silicon-based energy storage devices with electrolyte containing cyanate based compounds

An energy storage device comprising:

• a first electrode;
• a second electrode;
• a separator between the first electrode and the second electrode;
• and
• an electrolyte system comprising:
• a cyanate based compound;
• a linear carbonate;
• a cyclic carbonate;
• and
• a Li-containing salt;
• wherein said cyanate based compound is any one of formulae (VI), (VII) and (VIII):
• wherein R6, R7 and R8 are each independently selected from the group consisting of a C1-C8 alkylene, C2-C8 alkenylene, a C2-C8 alkynylene, a cycloalkylene, an arylene, —O—,
• and
• wherein R6, R7 and R8 may be optionally substituted by —F, alkyl, alkenyl, cycloalkyl, aryl, —CN, —N+C−, fluoro-alkyl, fluoro-ether, —N(CH3)2,
• and
• wherein RL, RM, RN and RO are each independently selected from the group consisting of a bond, a C1-C8 alkylene, a cycloalkylene, an arylene and —Si—, wherein RL, RM, RN and RO may be optionally substituted by —F, alkyl, alkenyl, alkynyl and aryl.