Reversible Li Insertion Studies on V 4 O 3 (PO 4 ) 3 as High Energy Storage Material for Li-Ion Battery Applications

Abstract

© The Author(s) 2016. Published by ECS. Li-insertion studies were performed on V 4 O 3 (PO 4 ) 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 Li 2 V 4 O 3 (PO 4 ) 3 , further lithium insertion lead to an amorphous material but the structure is completely recovered on charge.