Elucidating the Al3+ ion electrochemical behaviour of LiFePO4

This report illustrates an investigation on the electrochemical behaviour of LiFePO4 in Al3+ ion conducting aqueous electrolyte for the first time. It is inferred from the electrochemical measurements that Al3+ ion together with the structural Li+ ion could take part in the reversible oxidation-reduction process of LiFePO4. This is also supported by the ex-situ X-ray diffraction and X-ray photoelectron spectroscopy investigations. It is also found that leaching of iron species from LiFePO4 in the electrolyte results in low cycling stability. This could be mitigated to an appreciable degree by tweaking the electrolyte composition with a low fraction of iron species in the electrolyte.