Lithium insertion in Sn-P and Sn-B-P oxide glasses

<p> The behaviour of electrodes based on Sn2P2O7 and Sn2BPO6 glasses during cycling were characterized with diffuse IR reflectance. By removing the electrodes from the half-cells at different stages of the electrochemical cycling it was possible to follow the development of the glass structures during lithium insertion and extraction. It was found that the local network structure around the phosphate groups in the glass experience structural changes by the lithium insertion. These changes are not fully recovered by lithium extraction during the first cycle and are likely related to the initial irreversible loss of capacitance of the electrodes.