Water sensitivity of layered P2/P3-NaxNi0.22Co0.11Mn0.66O2 cathode material

Sodium-based layered oxides undergo several structural changes upon the (de-)sodiation process and reveal a strong tendency towards water intercalation at lower sodium contents. However, valuable information about their handling during the investigation are still rare. Herein, we report an investigation of the water sensitivity of layered NaxNi0.22Co0.11Mn0.66O2 with mixed P2/P3 structure via X-ray diffraction. At lower sodium contents, i.e. below x approximate to 0.33 or above 3.6 V vs. Na/Na+, a strong tendency for the uptake of water is observed, supported by the appearance of new diffraction peaks confirming a dramatically increased interlayer distance. However, at high sodium content (x > 0.33) the material can be processed in open air without major changes.