Pyrolyzed Bacterial Cellulose as the Backbone of the Cathode Catalyst-CoFe2O4 for the Li-O2 Battery

Abstract

In this paper, CoFe2O4@pyrolyzed bacterial cellulose (CFO@PBC) nanocomposites were synthesized by a hydrothermal process and an in situ composite technique as the cathode for rechargeable Li-O2 batteries (LOB). CoFe2O4@Ketjenblack (CFO@KB) were prepared in the same way as the comparison. The as-prepared materials were characterized by SEM, XRD, and BET. The LOB with CFO@PBC-3 showed a maximum initial discharge capacity of 2660 mAh g−1 (electrode) at the current density of 100 mAg−1, while the mass ratio of CoFe2O4 and pyrolyzed bacterial cellulose was 3. The cyclic voltammetry of the CFO@PBC nanocomposite electrodes was investigated at 0.1 mVs−1 in the voltage window of 2.0–4.5 V. With the limited capacity of 640 mAh g−1 (electrode), the CFO@PBC-3 electrode showed the best cycle stability and higher cutoff voltage of discharging. The pyrolyzed bacterial cellulose, as the fibrous 3D backbone in CFO@PBC nanocomposite electrodes, produced better results than the CFO@KB.