The production of a lithium-ion battery starts with high quality materials. Cathode Active Material (CAM) and the precursor product (PCAM) are central to battery performance. During PCAM production, pH stability is critical, as explained in this application note.
Lithium-ion battery performance with respect to charging and discharging depends greatly on the level of entrained impurities and uniformity of CAM particles. Therefore, PCAM production must be carefully controlled.
The pH level during PCAM production in a crystallizer has significant impact on product quality. A shift of only 0.1 pH can strongly influence particle size shape and distribution, so highly accurate and continuous pH measurement is vital. However, precipitating metal hydroxides in the crystallizer will coat a pH sensor and lead to false measurements. If not caught early, process consistency is impacted and off-spec product is the result.
The application note looks at the critical role of pH in lithium-ion battery PCAM production and issues around its control. It introduces METTLER TOLEDO's solution for reliable, on-line pH measurement for PCAM crystallizers. The InPro4260i pH sensor, with solid polymer reference electrolyte, is designed to withstand processes with high concentrations of suspended solids. In conjunction with the EasyClean 200e automated cleaning system, sensors can be kept free of build up and constantly deliver reliable measurements. For even greater process reliability, Intelligent Sensor Management (ISM) continuously monitors the pH sensor's performance and predictively communicates maintenance needs. With ISM, scheduling sensor calibration or replacement becomes easy and avoids the use of sensors that are not fit for purpose.