Functional integrated electromagnetic interference shielding in supercapacitors based on aligned SiC nanowires decorated vertical graphene nanosheets

To ensure the normal operation of electronic components without mutual infection in radiated electromagnetic waves, integrating the function of electromagnetic interference (EMI) into the energy storage device is a feasible measure. In this work, highly conductive vertical graphene sheets (VGNs) were in-situ introduced on aligned SiC nanowires (SiCNWs) arrays, constructing the core-shell SiCNWS@VGNs structure with good structural stability, robust interface, exceptional electrical conductivity and large specific surface area. Benefiting from the unique hierarchical array-like structure, the constructed self-supporting SiCNWS@VGNs electrode exhibited excellent electromagnetic interference (EMI) shielding and electrochemical performance. The specific capacitance of the SiCNWs@VGNs electrode could be up to 26.42 mF/cm2 at a current density of 0.2 mA/cm2, which was 185 % of that of pure SiCNWs electrode. Surprisingly, the assembled symmetrical supercapacitor displayed superior cycling stability with a capacitance retention of 120.06 % after 5000 cycles at 10 mA/cm2. Additionally, with the synergistic effect of VGNs, SiCNWs arrays and carbon fabric substrate, the SiCNWS@VGNs electrode also possessed excellent EMI shielding effectiveness (EMI SE) of 56.09 dB with a thickness of 0.4 mm. Remarkably, when the thickness of the electrode material reached 1.2 mm, the EMI SE was as high as 108.27 dB, owing to the excellent electrical conductivity and abundant heterogeneous interfaces. Significantly, this work provides a new inspiration for the construction of multifunctional supercapacitors with the ability of electromagnetic interference shielding.