Reversible Li Insertion Studies on V4O3(PO4)(3) as High Energy Storage Material for Li-Ion Battery Applications
Abstract
Li-insertion studies were performed on V4O3(PO4)(3) that belongs to the libscombite/lazulite family. Availability of multiple oxidation states and vacancies in crystal structure allows for the insertion of more than 7 lithium ions per formula unit. We will show that in the voltage window of 1-4 V vs. Li+/Li, 6.0 Li-ions could be inserted leading to a reversible capacity of 195 mAh/g at a C/5 rate. A structural transformation is observed from ex-situ XRD patterns after the insertion of 2 lithium at 2.4 V vs. Li+/Li, consistent with the available crystallographic sites in the structure. Interestingly we show that from this phase Li2V4O3(PO4)(3), further lithium insertion lead to an amorphous material but the structure is completely recovered on charge.