Electrolyte of 700-750V aluminum electrolytic capacitor

The invention provides a working electrolyte of a 700-750V aluminum electrolytic capacitor. The working electrolyte comprises a solute, a main solvent, an auxiliary solvent and an additive, wherein the solute is an ammonium salt of a high-molecular polymer as shown in the formula (I); the molecular weight distribution range of the high-molecular polymer is 20,000-100,000. By virtue of the electrolyte formed by the solute which is the ammonium salt of the high-molecular polymer as shown in the formula (I), the flash fire voltage of the capacitor can be obviously improved, and the electric conductivity of the obtained capacitor is relatively high; the capacitor after a high-temperature long-time test is low in capacity change rate, small in Tan delta and leakage current, and little in appearance change, the high-temperature stability is better, and the use requirement of the 700-750V ultrahigh-voltage aluminum electrolytic capacitor can be met. 本发明提供了种700-750V铝电解电容器工作电解液，包括：溶质、主溶剂、副溶剂及添加剂，其中溶质为式(I)所示高分子聚合物的铵盐，其