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The ever-growing demand for portable, bendable, twistable, and wearable microelectronics operating in a wide temperature range has stimulated an immense interest in the development of solid-state flexible energy storage devices using scalable fabrication technology. Herein, we developed additively manufactured graphene aerosol gel-based all-solid-state micro-supercapacitors (MSCs) via inkjet printing with functioning temperature in the range from −15 to +70 °C and exhibiting a super-stable and reliable electrochemical performance using interdigitated finger electrodes and PVA/H3PO4 solid-state electrolyte. The graphene aerosol gel was obtained using a scalable single step synthesis method from a gas phase precursor using a detonation process, producing a nanoscale shell type structure. The fabricated graphene aerosol gel-based solid-state MSC achieved a volumetric capacitance of 376.63 mF cm−3 (areal capacitance of 76.23 μF cm−2) at a constant current of 0.25 μA and demonstrated exceptional cyclic stability (∼99.6% of capacitance retention) over 10 000 cycles. To exploit the mechanical strength of the as-fabricated graphene aerosol gel-based solid-state MSC, its supercapacitive performance was scrutinized under various bending and twisting angles and the results showed excellent mechanical flexibility. Furthermore, to study the electrochemical performance of the as-fabricated graphene aerosol gel solid-state MSC in stringent surroundings, a broad temperature dependent supercapacitive analysis was performed as stated above. The electrochemical results of the as-fabricated graphene aerosol gel based all-solid-state MSC exhibit a highly potential route to develop scalable and authentic future miniaturized energy storage devices for IoT based smart electronic appliances. 

Abstract This study reports the superior performance of graphene nanosheet (GNS) materials over Vulcan XC incorporated as a cathode catalyst in Li–O2 battery. The GNSs employed were synthesized from a novel, eco-friendly, and cost-effective technique involving chamber detonation of oxygen (O2) and acetylene (C2H2) precursors. Two GNS catalysts i.e., GNS-1 and GNS-2 fabricated with 0.3 and 0.5 O2/C2H2 precursor molar ratios, respectively, were utilized in this study. Specific surface area (SSA) analysis revealed significantly higher SSA and total pore volume for GNS-1 (180 m2 g−1, 0.505 cm3 g−1) as compared with GNS-2 (19 m2 g−1, 0.041 cm3 g−1). GNS-1 exhibited the highest discharge capacity (4.37 Ah g-1) and superior cycling stability compared with GNS-2 and Vulcan XC. Moreover, GNS-1 demonstrated promising performance at higher current densities (0.2 and 0.3 mA cm−2) and with various organic electrolytes. The superior performance of GNS-1 can be ascribed to its higher mesopore volume, SSA, and optimum wettability compared to its counterparts.