| abstract |
Provided is an additive for an electrochemical element, the additive being capable of ensuring a high degree of safety in an electrochemical element. An additive for an electrochemical element, the additive being used in an electochemical element, wherein: the temperature at which the volume expansion rate is increased by a factor of 2 or more is greater than 150°C and less than 400°C; the contained amount of (A) elements belonging to group 2 of the periodic table is less than 100 mass ppm; the contained amount of (B) elements belonging to group 17 of the periodic table is less than 100 mass ppm; and the contained amount of (C) the elements Cr, Mn, Fe, Co, Ni, Cu, and Zn is less than 5 mass ppm. |