Laser irradiation of graphite foils as robust current collectors for high-mass loaded electrodes of supercapacitors

Conductive substrates with low cost, lightweight, and chemical stability have been highly recognized as alternative current collectors for energy storage devices. Graphite foil is promising to fulfill these requests, whereas the inert surface chemistry denies its possibility as the carrier with high-mass loading active species. Herein, we report a facile yet efficient laser-mediated strategy to fast regulate graphite foils for robustly loading active species. The smooth and hydrophobic graphite foil surface turned to be a rough, super-hydrophilic one containing oxygen-rich clusters after lasering. The reconstructed surface affords anchors for active species, such as nanostructured MnO2, FeOOH, and Fe2O3, with the highest loading mass of 20 mg.cm(-2). The high-mass loading MnO2 electrode offers an areal capacitance of 3933 mF.cm(-2) at 1 mA.cm(-2). Then, the asymmetric supercapacitor, fabricated by MnO2 and Fe2O3 deposited laser-irradiated graphite foils, exhibits improved performance with high energy density, large power capability, and long-term stability. The strategy suggests a reliable way to produce alternative current collectors for robust energy storage devices.