In the rapidly growing lithium-ion battery industry, the production and refinement of battery-grade salts for manufacturing essential cathode materials involves some highly critical processes. During PCAM production in crystallizers, an oxygen-free atmosphere is essential.
Oxygen in the process easily leads to formation of undesired NCM oxides that will lead to PCAM degradation. This is why crystallizers are run under an inert atmosphere. But measuring O2 in these vessels is not straightforward.
This application note looks at the issues around the presence of oxygen in crystallizers and how PCAM degradation can be avoided with in situ O2 monitoring.
Lithium-ion battery charging and discharging performance is closely related to the quality of the Cathode Active Material (CAM) and the precursor product, PCAM. Impurities in the PCAM can greatly impact battery performance, as can the size, shape, and distribution of PCAM particles.
For nickel, cobalt and manganese (NCM)-type cathodes, PCAM is made through a co-precipitation reaction of Ni, Co, and Mn hydroxides in a stirred tank reactor/crystallizer. Air/oxygen in the vessel's headspace leads to the formation of unwanted oxides, so monitoring the headspace for O2 is critical.
Continuous, oxygen measurement with an in situ sensor is highly recommended to provide instant notification of oxygen, therefore allowing corrective action to prevent the production of off-spec product.
The high humidity and splashing from slurries make conditions difficult for in situ sensors. METTLER TOLEDO offer a measurement system designed to tolerate PCAM production.