提出了一种在冰-水体系中快速测定LiPF₆电解液中游离酸含量（以氟化氢计）的方法。优化的仪器工作条件为：①反应温度为0~4℃；②支持电解质为1.0 mol·L^-1 KCl溶液；③pH复合玻璃电极为指示电极，铂片电极和铂丝辅助电极为工作电极对；④恒电流为0.250~20.00 mA；⑤滴定终点为pH 7.40。通过工作电极上电解产生滴定剂OH^-与LiPF₆电解液中的游离酸反应至滴定终点，并依据法拉第电解定律计算得到LiPF₆电解液中的游离酸含量。结果表明：整个测定过程可控制在5 min之内；标准曲线的线性范围为5.0~200 μg，测定下限为5.0 μg；加标回收率为99.7%~102%。按此方法分析了4个实际样品，测定值相对标准偏差（n=5）均小于1.0%，和非水库仑滴定法的基本一致，远优于电位滴定法的。

A new method for rapid determination of the content of free acid in LiPF₆ electrolyte in an ice-water system was proposed. The optimized instrumental working conditions were found as follows:① 0-4℃ in the ice-water system as reaction temperature; ② 1.0 mol·L^-1 KCl solution as supporting electrolyte; ③ composite glass electrode as indicating electrode, platinum electrode and platinum wire auxiliary electrode as working electrode pairs; ④ constant current of 0.250-20.00 mA; ⑤ pH 7.40 as the titration end-point. The titrant OH^- generated by constant current electrolysis of water was reacted with free acid in the electrolyte, and the content of free acid obtained was determined by the Faraday's law of electrolysis. The results showed that the whole measurement process could be completed within 5 minutes. The linearity range of the standard curve was kept in the range of 5.0-200 μg, with lower limit of determination of 5.0 μg; the recoveries found by the spiked test were ranged from 99.7% to 102%. Four actual samples were analyzed by this method, giving RSDs (n=5) of the measured values less than 1.0%, consistent with the coulometric titration in non-aqueous systems and far superior to the potentiometric titration method.