Investigation of Li+ insertion in columbite structured FeNb2O6 and rutile structured CrNb2O6 materials

• FeNb2O6 and CrNb2O6 cathode materials achieved.
• Reversible lithium insertion proved in both FeNb2O6 and CrNb2O6.
• Nb(V)/Nb(IV) redox couple dominant rather than Cr(III)/Cr(II).
• Initial drop in capacity interpreted as a result of channel blocking.
• Strategies for future material developments proposed.

Lithium insertion in FeNb2O6 and CrNb2O6 has been investigated using the galvanostatic charge–discharge method and showed that more than half of the intercalated Li+ during first cycle is retained in the structure and is not de-intercalated during subsequent cycles. The effects of sintering on FeNb2O6 were investigated with lower applied temperatures yielding higher Li+ intercalation capability. Post galvanostatic XRD shows that the initial phase has been retained during cell cycling. Cyclic voltammetry reveals that chromium also takes part in electro-chemical activity in CrNb2O6.

Figure optionsDownload as PowerPoint slide