Fabrication Of Hybrid Supercapacitors Research Articles

Fabrication of Hybrid Supercapacitor by MoCl5 Precursor‐Assisted Carbonization with Ultrafast Laser for Improved Capacitance Performance

AbstractHybrid supercapacitors use electric double‐layer capacitance and Faradaic pseudocapacitance as energy storage mechanisms. This type of supercapacitor is becoming a prime candidate for next‐generation energy storage devices, with advantages in terms of energy density, specific capacitance, and life cycle. However, reducing the electrode area and increasing the specific capacitance of hybrid supercapacitors remain challenging. In this study, a MoCl5 Precursor‐assisted Ultrafast Laser Carbonization (MPAULC) method to fabricate symmetric hybrid supercapacitors with improved capacitance and reduced size is proposed. The method uses an ultrafast laser to induce the formation of carbon/MoO3 composite with the assistance of the MoCl5 precursor. This ultrafast laser carbonization method exhibited high processing precision. The role of the precursor in laser processing is studied using time‐resolved imaging and temperature calculations. The specific area capacitance of the C/MoO3 hybrid supercapacitor is 11.85 mF cm−2, 9.2 times higher than that of the laser‐induced carbon supercapacitor without precursor. The MPAULC method provides a reliable pathway for fabricating miniaturized hybrid supercapacitors with carbon/metal oxide composite electrodes on polymer substrates.

Rational design of Cu-doped Co3O4@carbon nanocomposite and agriculture crop-waste derived activated carbon for high-performance hybrid supercapacitors

Development of structurally stable transition metal-oxides and cost-effective biomass-based carbon materials have attracted considerable attention in the fabrication of hybrid supercapacitors. In this work, we designed spinal copper-doped cobalt oxide (Cu-Co3O4) nanoboxes decorated functionalized-carbon nanotubes (f-CNTs) as hybrid redox-type material and agriculture crop-waste derived mesoporous activated carbon as capacitive-type electrode for high-performance hybrid supercapacitors. Structural properties reveal that the Cu-Co3O4has a cubic spinel structure and Raman spectra results confirm the presence of f-CNTs. The hybrid composite material demonstrates superior redox behavior with excellent structural durability. The hybrid electrodes exhibit maximum specific capacity of 130.7 mAh g−1 at 0.5 A g−1 with 86.7 % capacitance retention over 10,000 cycles. Besides, the crop waste-derived activated carbon demonstrates high surface area (1549 m2g-1), mesoporous characteristics and excellent capacitive behavior. The high voltage hybrid supercapacitor is further fabricated with Cu-Co3O4@F-CNTs as battery-type and biomass-derived activated carbon as capacitive-type electrodes, which demonstrate high energy density of 30.8 Wh kg−1 at 5972 W kg -1 power density. The augmented results indicate that the hybrid composites with biomass-derived carbon materials pave the way for design of eco-friendly energy storage applications.

Improvement of capacitive performance of polyaniline based hybrid supercapacitor

This study focuses on synthesis of polyaniline composites and application as electrode material in the fabrication of hybrid supercapacitors. Hybrid supercapacitors were fabricated using aluminum foil as current collector, and conductive Polyaniline (PANI) composites as electrode materials. Cobalt oxide (Co2O3), ammonium peroxydisulfate (APS) were used along with PANI in the preparation of electrodes of the supercapacitor. Polyaniline and its various composites were used in the cathode and activated carbon in the anode (positive electrodes) of the asymmetric hybrid supercapacitor. Electrochemical performance of the supercapacitors has been evaluated on the basis of capacitive properties (i.e. capacitance, energy density and power density). Area of the supercapacitor, applied voltage for charging and composition of cathode materials have been optimized in this study. The optimum area of the supercapacitor was found 30 cm2 at optimum voltage 5 V. The result showed that supercapacitor fabricated using polyaniline (PANI) as cathode material with Al foil as current collector provided highest capacitance of 249 F/g, Energy density of 31 Wh/kg and Power density of 18 W/kg. Among various PANI composites (Ni-PANI, Cu-PANI, CNF-PANI) synthesized in this study, Ni-PANI composite showed highest capacitance of 336 F/g, energy density of 42 Wh/kg, and power density of 31 W/kg. The result indicates that Ni-PANI composite has high potential as cathode materials for the hybrid supercapacitor.