Advanced rechargeable aluminium ion battery with a high-quality natural graphite cathode.

ABSTRACT: Recently, interest in aluminium ion batteries with aluminium anodes, graphite cathodes and ionic liquid electrolytes has increased; however, much remains to be done to increase the cathode capacity and to understand details of the anion-graphite intercalation mechanism. Here, an aluminium ion battery cell made using pristine natural graphite flakes achieves a specific capacity of ?110?mAh?g-1 with Coulombic efficiency ?98%, at a current density of 99?mA?g-1 (0.9?C) with clear discharge voltage plateaus (2.25-2.0?V and 1.9-1.5?V). The cell has a capacity of 60?mAh?g-1 at 6?C, over 6,000 cycles with Coulombic efficiency ? 99%. Raman spectroscopy shows two different intercalation processes involving chloroaluminate anions at the two discharging plateaus, while C-Cl bonding on the surface, or edges of natural graphite, is found using X-ray absorption spectroscopy. Finally, theoretical calculations are employed to investigate the intercalation behaviour of choloraluminate anions in the graphite electrode.

SUBMITTER: Wang DY 

PROVIDER: S-EPMC5316828 | biostudies-other | 2017 Feb

REPOSITORIES: biostudies-other