Phosphazene derivative, composition, and an electrochemical device comprising the same

A phosphazene derivative having a structure of Formula (I):

• wherein n is an integer of 3 to 6, R1 and R2 are independently selected from a group represented by Formula (I-1) or Formula (I-2),
• wherein A is —R3—O—R4, —R3—CH3-m(OR4)m, —CH3-m(OR4)m or
• wherein R3 is unsubstituted C1-C8 alkylene or C1-C8 alkylene substituted with C1-C8 alkyl, R3is C1-C8 alkyl, R5 is C1-C3 alkyl, R6 is C1-C3 alkylene, R7 is C1-C3 alkyl, x is 1 or 2, m is 2 or 3, p is a number of the A bonded to a carbon in a benzene ring to which the A is attached, and p is an integer of 0 to 3;
• B is C1-C8 alkoxy or C1-C8 alkyl, and q is an integer of 0 to 3;
• and
• 0<p+q≤5.