| 摘要 |
The present invention provides a nonaqueous electrolytic solution capable of suppressing worsening of heat stability of a negative electrode and improving safety of an energy storage device while maintaining high-load charging and discharging cycle properties at a high temperature, an energy storage device using the same, and a phosphonoformic acid compound to be used for the same. The nonaqueous electrolytic solution having an electrolyte salt dissolved in a nonaqueous solvent contains 0.001 to 5% by mass of at least one selected from a phosphonoformic acid compound having at least one carbon-carbon unsaturated bond, which is represented by the following general formula (I), and a phosphonoformic acid compound having a carbon-carbon unsaturated bond or two phosphonocarbonyl groups, which is represented by the following general formula (II). In the formula (I), each of R 1 to R 3 is an aliphatic organic group, provided that at least one of R 1 to R 3 represents a carbon-carbon unsaturated bond-containing aliphatic organic group. In the formula (II), each of R 4 and R 5 represents an alkyl group, a cycloalkyl group, or an aryl group, and R 4 and R 5 may be bonded to each other to form a ring structure. m represents 1 or 2; when m is 1, then R 6 represents an aryl group; when m is 2, then R 6 represents an alkylene group, an alkenylene group, or an alkynylene group; and a part of hydrogen atoms of R 4 to R 6 may be substituted with a halogen atom. |
