Pentafluorophenyloxy compound, and nonaqueous electrolyte solution and lithium secondary battery using same

A lithium secondary battery comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte solution which includes an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolyte solution comprising a pentafluorophenyloxy compound in an amount of 0.01 to 10% by weight based on the weight of the nonaqueous electrolyte solution, the pentafluorophenyloxy compound being represented by the following formula (II):

• wherein R3 represents a —COCO— group, a C═O group, a S═O group or a S(═O)2 group, R4 represents a C1 to C12 alkyl group, a C3 to C12 cycloalkyl group, a C2 to C12 alkenyl group, a C3 to C12 alkynyl group, a C6 to C18 aryl group or a C7 to C20 aralkyl group wherein at least one of the hydrogen atoms of R4 may optionally be substituted with a halogen atom, with the proviso that R4 represents a C2 to C12 alkenyl group or a C3 to C12 alkynyl group when R3 represents a C═O group.

A nonaqueous electrolyte solution, in which an electrolyte salt is dissolved in a nonaqueous solvent, the nonaqueous electrolyte solution comprising a pentafluorophenyloxy compound in an amount of 0.01 to 10% by weight based on the weight of the nonaqueous electrolyte solution, the pentafluorophenyloxy compound being represented by the following formula (II):

• wherein R3 represents a —COCO— group, a S═O group or a S(═O)2 group, R4 represents a C1 to C12 alkyl group, a C3 to C12 cycloalkyl group, a C2 to C12 alkenyl group, a C3 to C12 alkynyl group, a C6 to C18 aryl group or a C7 to C20 aralkyl group, wherein, optionally, at least one of the hydrogen atoms of R4 may be substituted with a halogen atom.

A lithium secondary battery comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte solution which includes an electrolyte salt dissolved in a nonaqueous solvent, the nonaqueous electrolyte solution comprising a pentafluorophenyloxy compound in an amount of 0.01 to 10% by weight based on the weight of the nonaqueous electrolyte solution, the pentafluorophenyloxy compound being represented by the following formula (II):

• wherein R3 represents a —COCO— group, a S═O group or a S(═O)2 group, R4 represents a C1 to C12 alkyl group, a C3 to C12 cycloalkyl group, a C2 to C12 alkenyl group, a C3 to C12 alkynyl group, a C6 to C18 aryl group or a C7 to C20 aralkyl group, wherein, optionally, at least one of the hydrogen atoms of R4 may be substituted with a halogen atom.

A nonaqueous electrolyte solution, in which an electrolyte salt is dissolved in a nonaqueous solvent, the nonaqueous electrolyte solution comprising a pentafluorophenyloxy compound in an amount of 0.01 to 10% by weight based on the weight of the nonaqueous electrolyte solution, the pentafluorophenyloxy compound being represented by the following formula (II):

• wherein R3 represents a —COCO— group, a C═O group, a S═O group or a S(═O)2 group, R4 represents a C1 to C12 alkyl group, a C3 to C12 cycloalkyl group, a C2 to C12 alkenyl group, a C3 to C12 alkynyl group, a C6 to C18 aryl group or a C7 to C20 aralkyl group wherein at least one of the hydrogen atoms of R4 may optionally be substituted with a halogen atom, with the proviso that R4 represents a C2 to C12 alkenyl group or a C3 to C12 alkynyl group when R3 represents a —COCO— group, a S═O group, or a S(═O)2 group.