S. Wang, X. Wang, C.L. Sun*, Z.-S. Wu*

Journal of Energy Chemistry, 2021, 61, 23-28.

DOI: 10.1016/j.jechem.2021.01.019 [PDF]

Synthesis and applications of three-dimensional (3D) porous graphene frameworks (GFs) have attracted extensive interest owing totheir intriguing advantages of high specific surface area, enriched porosity, excellent electrical conductivity,exceptional compressibilityandprocessability. However, it is still challenging foreconomically viable,fast and scalable assembly of3D GFs at roomtemperature. Herein, we reported a one-step scalable strategy for fast self-assembly of graphene oxide into 3D macroscopically porous GFs, with assistance of polyoxometalates (POM) as functional cross-linker and hydrazine hydrate as reductant at room temperature. The resulting 3D interconnected macroporous network POM-GFsuniformly decorated with ultrasmall POM nanoclusterswere directly processed into binder-/additive-free film compact electrodes (1.68 g cm^-3) with highly aligned, layer-stacked structure and electricallyconductivity(622 S m^-1) for high-performance supercapacitors, showing animpressive gravimetric capacitance of205 F g^-1, volumetric capacitance of 334 F cm^-3(1 mV s^-1),and remarkable cycling stability with capacitance retention of 83% after 10000 cycles, outperforming the most reported GFs. Further, the solid-state supercapacitors offered excellent gravimetric capacitance of157 F g^-1,exceptionally volumetric capacitance of 115 F cm^-3at 2 mV s^-1,andvolumetric energy density of 2.6 mWh cm^-3.Therefore, this work will open novel opportunities to room-temperature fast assembly of 3D porous graphene architecturesforhigh-energy supercapacitors.