Ab initio investigations of the electronic structures and chemical bonding in LiCo6P4 and Li2Co12P7

• Chemical bonding resolved in the metal-rich phosphides LiCo6P4 and Li2Co12P7.
• Strong covalent Co–P bonding character in the [Co6P4] and [Co12P7] substructures.
• Total energy calculations indicate stability of the de-lithiated substructures.

The electronic structures of the metal-rich phosphides LiCo6P4 and Li2Co12P7 were studied by DFT calculations. Both phosphides consist of three-dimensional [Co6P4] and [Co12P7] polyanionic networks which leave hexagonal channels for the lithium atoms. COOP data show strong Co–P and Co–Co bonding within the polyanions. The lithium atoms have trigonal prismatic phosphorus coordination. Total energy calculations indicate stability upon de-lithiation towards the Co6P4 and Co12P7 substructures

The cobalt–phosphorus networks in LiCo6P4 and Li2Co12P7.Figure optionsDownload as PowerPoint slide