Disassembly–Reassembly Approach to RuO 2 /Graphene Composites for Ultrahigh Volumetric Capacitance Supercapacitor

A porous, yet compact, RuO2/graphene hybrid is successfully prepared by using a disassembly–reassembly strategy, achieving effective and uniform loading of RuO2 nanoparticles inside compact graphene monolith. The disassembly process ensures the uniform loading of RuO2 nanoparticles into graphene monolith, while the reassembly process guarantees a high density yet simultaneously unimpeded ion transport channel in the composite. The resulting RuO2/graphene hybrid possesses a density of 2.63 g cm−3, leading to a record high volumetric capacitance of 1485 F cm−3 at the current density of 0.1 A g−1. When the current density is increased to 20 A g−1, it remains a high volumetric capacitance of 1188 F cm−3. More importantly, when the single electrode mass loading is increased to 12 mg cm−2, it still delivers a high volumetric capacitance of 1415 F cm−3 at the current density of 0.1 A g−1, demonstrating the promise of this disassembly–reassembly approach to create high volumetric performance materials for energy storage applications.