Reduced graphene composited N-containing polymer engineered by ball milling as electrode for high-volumetric-performance supercapacitor

The poor inherent conductivity of nitrogen containing polymers (excluding nitrogen-containing conductive polymers) with electrochemically-active species hampers their application in energy storage. Combining conductive substrates with polymers is highly essential to fabricate new electrode materials. Herein, we exploited a facile ball milling compositing technique to prepare reduced graphene oxide composited nitrogen containing polymer. In our strategy, the low-cost melamine was employed as nitrogen sources, which was highly mixed with different ratio of graphene oxide (GO) by ball milling and then was annealed to prepare the target products (rGON). The resultant rGON owns a sheet-like morphology, homogenous element distribution and large packing density (1.189–1.343 g cm⁻³). As electrode for supercapacitor, a superior volumetric performances were achieved with high capacitance of 410 F cm⁻³@1.0 A g⁻¹, large energy density of 30.8 Wh L⁻¹@1230 W L⁻¹, which is much higher than that of MN300 (13.3 Wh L⁻¹@1338 W L⁻¹) and rGO (6.5 Wh L⁻¹@ 648 W L⁻¹) based device due to the improved surface wettability and structural stability of the composite material. And more, a superlong cycling stability with near 100 % capacitance retention after continual charge/discharge for 30,000 cycles. The present approach is versatile and opens an avenue to prepare composite material for multiple application in fields like catalysis, sorption, energy storage and so on.