Chemical stability of layered lithium cobalt nitrides in air

The chemical stability in air of a layered lithium nitridocobaltate Li2.13Co0.43N has been investigated using in situ XRD diffraction as a function of time. A high reactivity of the nitride with air moisture is found with the rapid emergence of lithium hydroxide. The ageing process finally leads to the decomposition of the nitride into lithium carbonate (Li2CO3), cobalt hydroxide (Co(OH)2) and the release of gaseous NH3. The effect of the ageing process on the electrochemical properties of this promising anode material for Li-ion batteries is reported. The discharge–charge properties of the compound slightly deteriorate after few hours while they are dramatically affected after 15 h. The present results suggest handling of these anodic materials in dry air would be possible with satisfactory electrochemical properties.

► Ageing process in air of a lithiated nitridocobaltate anode material for lithium-ion batteries.
► X-ray diffraction characterisation of changes in chemical composition and structure.
► Influence of the ageing time in air on the electrochemical properties.