A simple strategy to improve the electrochemical performance of rechargeable aqueous Al-graphite battery

We report here the improved performance of a rechargeable Al-graphite cell in aqueous electrolyte which is achieved by a modification of the graphite electrode. A simple electrochemical method was adopted to exfoliate the graphite electrode which was further treated at 800 degrees C to obtain thermally exfoliated graphite. The thermal treatment resulted in formation of high surface area nanosized graphite flakes. This thermally exfoliated graphite shows a discharge capacity of 100-120 mAhg- 1, whereas exfoliated graphite shows only 50-60 mAhg- 1 at current rate of 0.5 Ag-1. The improvement is due to lesser charge transfer resistance at the electrode-electrolyte interface. The influence of 'water-in-salt' electrolyte in the electrochemical performance was also investigated.