Compound, and lithium secondary battery electrolyte and lithium secondary battery which comprise same

A compound represented by Formula 1 below:

• wherein X1 and X2 are each independently —O—, —S—or —NR′—;
• R′ is a linear, branched or cyclic C1 to C10 hydrocarbon group which may contain a hetero atom or halogen atom;
• X3 and X4 are each independently carbon, phosphorus or sulfur with a proviso that at least one of X3 and X4 is phosphorus or sulfur;
• A is boron or phosphorus;
• R is each independently hydrogen;
• a halogen atom;
• a linear, branched or cyclic C1 to C10 hydrocarbon group which may contain a halogen atom;
• OR′;
• or OSiR′3;
• L is a C1 hydrocarbon group unsubstituted or substituted by a halogen atom;
• or oxygen;
• M is lithium, sodium, potassium or ammonium (NR″4);
• R″ is each independently hydrogen;
• or a linear, branched or cyclic C1 to C10 hydrocarbon group which may contain a hetero atom or halogen atom;
• a and a′ are each independently an integer of 0 to 2;
• b and b′ are each independently an integer of 0 to 2 with a proviso that b-a and b′-a′ are an integer of 0 or more;
• c is an integer of 0 to 4;
• d is an integer of 0 to 3;
• and
• e is an integer of 1 to 3.