ADDITIVE FOR ELECTROCHEMICAL DEVICE, BINDER COMPOSITION FOR ELECTROCHEMICAL DEVICE, SLURRY COMPOSITION FOR ELECTROCHEMICAL DEVICE, ELECTRODE FOR ELECTROCHEMICAL DEVICE, AND ELECTROCHEMICAL DEVICE

Provided is an additive for an electrochemical device that can ensure a high level of safety of an electrochemical device. The additive for an electrochemical device is an additive for an electrochemical device that is used in an electrochemical device, for which a temperature at which a volume expansion ratio thereof reaches a factor of 2 or more is higher than 150° C. and lower than 400° C., and in which the content of (A) each element belonging to group 2 of the periodic table is less than 100 mass ppm, the content of (B) each element belonging to group 17 of the periodic table is less than 100 mass ppm, and the content of (C) each element among Cr, Mn, Fe, Co, Ni, Cu, and Zn is less than 5 mass ppm.