107 results about "Acid–base titration" patented technology

The invention relates to a method of detecting surface lithium of a ternary cathode material. The method includes stirring and mixing a ternary cathode material sample and water, filtering the mixture to obtain filtrate that is a solution to be detected, adding a phenolphthalein indicator into the solution to be detected, titrating the mixture with a standard hydrochloric acid solution until the mixture is colorless, recording the volume V1 of the consumed standard hydrochloric acid solution, then adding a methyl red indicator into the mixture, titrating the system with a standard hydrochloric acid solution until the color is turned from yellow to orange, heating and boiling the system to allow the color to be turned back from the orange to yellow, cooling the system to room temperature, titrating the system with the standard hydrochloric acid solution until the system is reddish that is adopted as a terminal point, recording the volume V2 of the consumed standard hydrochloric acid solution in the whole titrating process, and calculating the surface lithium content of the ternary cathode material according to a formula (1). According to the method, the surface lithium content of the ternary cathode material is detected through selecting the indicators and through an acid-base titration process, influences of an intermediate that is LiHCO3 on titration data are taken into full consideration, the surface lithium content measuring error of the acid-base titration process is reduced and detection accuracy is improved.