Identification of critical moisture exposure for nickel-rich cathode active materials in lithium-ion battery production

Abstract

Nickel-rich cathode materials are crucial for improving lithium-ion battery performance due to their potential for high energy densities. However, their sensitivity to humidity demands cost- and energy-intensive dry room production environments. This study examined the storage stability of a surface-treated nickel-rich cathode (≈ 91 mol% nickel) under industry-relevant scenarios to assess the required atmospheres and the impact of short moisture exposure on material and cell performance. Calendered and non-calendered cathodes were produced in a dry room with a dew point of −60 °C and then exposed to dew points of up to −20 °C and ambient atmosphere (dew point ≈ 5 °C). Analysis showed that calendered electrodes were more susceptible to carbonate formation at higher dew points. Cycling tests of single-layer full-pouch cells indicated that carbonate impurities, predominantly present on electrodes stored in ambient conditions, reduced energy efficiency during formation but did not significantly affect long-term performance. These findings suggest that less stringent dry room requirements could reduce production costs and energy consumption for high-performance lithium-ion battery cells. • Study moisture effects on Ni-rich cathodes (≈91 mol% Ni) in industrial scenarios. • Electrodes more prone to moisture and carbonate surface impurities when calendered. • No impact of dry room downtime at dew point −20 °C on cell performance. • 72-h air-exposed electrodes perform like those handled at dew point −60 °C.