In a multi-component co precipitation system, pH control is crucial. Because the alkaline ammonia mixed solution is constantly added and complex reactions occur, it is difficult to control the pH value. In order to completely solve this problem, the R&D team of Changsha Sichen Instrument Technology Co., Ltd. has recently developed the third-generation high-precision pH automatic control system (mainly including the upgraded SC-100A plus version/SC-300A plus version and the scientific research SC-100A Max version/SC-300A Max version). This system adopts touch screen operation and is a new type of automated control system that integrates real-time online display, measurement, and automatic adjustment of pH value (acid/alkali) solution. Widely used in places where pH value needs to be controlled and adjusted, such as laboratory researchers monitoring and controlling the acidity and alkalinity of solutions in various reaction vessels, reaction tanks, biochemical containers, catalytic fields, and bioreactors. For laboratories in higher education institutions and research institutes; Specially designed and manufactured by domestic and foreign R&D enterprises and R&D production departments in biopharmaceuticals, life sciences, new materials, etc. And it has completely independent intellectual property rights, obtaining one national invention patent (ZL201410349779.8) and multiple utility model patents (ZL201721373766.X); ZL 201420406067.0; ZL201420406055.8.

In addition, hydroxides containing Mn are prone to form manganese oxides. When the temperature exceeds 60 ℃ and the pH value increases to a certain range, manganese hydroxides do not precipitate and preferentially form manganese oxides. When there is an excess of alkali and oxygen present, it is also easy to form certain manganese oxides. Researchers have found that within the range of 8<pH<10, the supersaturation of the co precipitation system decreases continuously with the increase of pH value, the nucleation rate of crystals slows down, the growth rate of crystals accelerates, and the resulting grain size continues to increase; Within the range of 10<pH<12, the supersaturation of the co precipitation system increases continuously with the increase of pH value, and the resulting particle size also decreases continuously. When the pH of the control system is 11, the precipitate product has a single morphology, good sphericity, narrow particle size distribution, and high tap density, which is beneficial for improving the electrochemical performance of the positive electrode material.