Influence of microstructure on the capacitive performance of polyaniline/carbon nanotube array composite electrodes

3D-Printed Nanocarbon Polymer Conductive Structures for Electromagnetic Interference Shielding

Electromagnetic interference (EMI) significantly affects the performance and reliability of electronic devices. Although current metallic shielding materials are effective, they have drawbacks such as high density, limited flexibility, and poor corrosion resistance that limit their wider application in modern electronics. This study investigates the EMI shielding properties of 3D-printed conductive structures made from polylactic acid (PLA) infused with 0D carbon black (CB) and 1D carbon nanotube (CNT) fillers. This study demonstrates that CNT/PLA composites exhibit superior EMI shielding effectiveness (SE), achieving 43 dB at 10 GHz, compared to 22 dB for CB/PLA structures. Further, conductive coating of polyaniline (PANI) electrodeposition onto the CNT/PLA structures improves the SE to 54.5 dB at 10 GHz. This strategy allows fine control of PANI loading and relevant tuning of SE. Additionally, the 3D-printed PLA-based composites offer several advantages, including lightweight construction and enhanced corrosion resistance, positioning them as a sustainable alternative to traditional metal-based EMI shielding materials. These findings indicate that the SE of 3D-printed materials can be substantially improved through low-cost and straightforward PANI electrodeposition, enabling the production of customized EMI shielding materials with enhanced performance. This novel fabrication method offers promising potential for developing advanced shielding solutions in electronic devices.

Large-Area Fabrication of Porous Graphene Networks on Carbon Fabric via Millisecond Photothermal Processing of Polyaniline for Supercapacitors

Supercapacitors demonstrate promising potential for flexible, multi-functional energy storage devices; however, their widespread adoption is confronted by fabrication challenges. To access a combination of desirable device qualities such as flexibility, lightweight, structural stability, and enhanced electrochemical performance, carbon fiber (CF) can be utilized as a current collector, alongside graphene as an electrochemically active material. Yet achieving a cost-effective, large-scale graphene production, particularly on CF, remains challenging. Here, a rapid (<1 min) photothermal approach is developed for the large-scale production of graphene directly onto CF, utilizing polyaniline (PANI) as a polymer precursor. The in situ electropolymerization of PANI on CF facilitates its rapid synthesis on large areas, followed by conversion into graphene networks, enabling the binder-free fabrication of supercapacitor devices. These devices exhibit an areal capacitance of 180 mF cm-2 (at 2 mA cm-2 in 1 m H2SO4), an order of magnitude higher than other fabric-based devices. Moreover, the devised photothermal strategy allows for one-step preparation of supercapacitor devices on areas exceeding 100 cm-2, yielding an absolute areal capacitance of 4.5 F. The proportional increase in capacitance with device area facilitates scaling and indicates the commercial viability of this approach for low-cost, energy-efficient, and high-throughput production of lightweight, high-performance graphene-based multi-functional supercapacitor devices.

Highly efficient Ni-Mo-P composite rare earth elements electrode as electrocatalytic cathode for oil-based drill sludge treatment

It is considered an effective strategy to improve electrochemical performance that introducing rare elements into metal catalysts, which would provide abundant electrochemical active sites and be a benefit for redox reactions. A new Ni-Mo-P composite electrode material modified with rare earth elements (light rare earth Nd and heavy rare earth Yb) was prepared, evaluating the current density of direct current electrodeposition, the doping ratio of Yb and Nd, and the cyclic voltammetry deposition (CVD) cycle numbers on electrode structure and electrochemical performance. The results showed that the electrode has the most obvious amorphous state, the lowest hydrogen evolution overpotential (41.5 mV vs Ag/AgCl) and charge transfer resistance (15.74 Ω/cm²), and remarkable stability when the molar ratio of Yb and Nd was 8:2 and the 20 cycle numbers under the CVD condition. The electrochemical performance and characterization of the electrode showed that there was a good synergistic effect between rare earth elements (Yb, Nd) and Ni-Mo-P alloys. The oil-based drill sludge (OBDS) treatment indicated that the organic matter content is significantly reduced by using the above-modified electrode as the cathode, and the COD and petroleum removal rate can reach up to 85.4 ± 1.2% and 66.2 ± 5.9%. The effect of degradation for aliphatic hydrocarbon was better than aromatic hydrocarbons and no other intermediates are produced during the degradation, which may eventually mineralize the organic matter. This research provided technical support for the preparation of new Ni-Mo-P electrodes modified with rare earth elements and confirmed that electrocatalytic technology was a suitable method for OBDS treatment.

Improving the Performance of a Graphite Foil/Polyaniline Electrode Material by a Thin PEDOT:PSS Layer for Application in Flexible, High Power Supercapacitors

In this study, we present a novel strategy for enhancing polyaniline stability and thus obtaining an electrode material with practical application in supercapacitors. A promising (graphite foil/polyaniline/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) GF/PANI/PEDOT:PSS) electrode material was characterized and used in the construction of a symmetric supercapacitor that provides an outstanding high power density. For this purpose, the electropolymerization of PANI was carried out on a graphite foil and then a thin protective layer of PEDOT:PSS was deposited. The presence of the nanometer PEDOT:PSS layer made it possible to widen the electroactivity potential range of the electrode material. Moreover, the synergy between materials positively affected the amount of accumulated charge, and thus the thin PEDOT:PSS layer contributed to enhancing the specific capacity of the electrode material. The electrochemical performance of the GF/PANI/PEDOT:PSS electrode, as well as the symmetrical supercapacitor, was investigated by cyclic voltammetry and galvanostatic charge/discharge cycles in 1 M H2SO4 at room temperature. The fabricated electrode material shows a high specific capacitance (Csp) of 557.4 Fg-1 and areal capacitance (Careal) of 2600 mF·cm-2 in 1 M H2SO4 at a current density of 200 mA·cm-2 (~4 A·g-1). The supercapacitor performance was studied and the results show that a thin PEDOT:PSS layer enables cycling stability improvement of the device from 54% to 67% after 10,000 cycles, and provides a high specific capacity (159.8 F·g-1) and a maximum specific power (18,043 W·kg-1) for practical applications.

Efficient Design for a High-Energy and High-Power Capability Hybrid Electric Power Device with Enhanced Electrochemical Interfaces

Fabrication of novel electrode architectures with tailored electrochemical interfaces (EI) is an effective strategy for enhancing charge and mass transport processes within electrochemical devices. Here, we design and fabricate a well-hybrid electrode based on the coupling of polyaniline (PANI) nanowires and Pt-based electrocatalysts to manufacture a hybrid electric power device (HEPD) combining the advantages of supercapacitors and fuel cells. Because of the boosted charge transfer between PANI nanowires and Pt-based materials via enhanced EIs, the HEPD assembled with hybrid electrodes shows remarkable performance with a peak power density of 222 mW cm^-2, a specific power of 3810 W kg^-1, and a specific energy of 2100 Wh kg^-1, normalized to the mass of membrane electrode assemblies. The in situ Raman spectra and extended electrochemical studies demonstrate the intrinsic mechanism of charge transfer processes within hybrid electrodes, shedding light on the alternative progress of electrochemical energy conversion systems and storage devices.

Ultrasound promoted transition metal doped polyaniline nanofibers: Enhanced electrode material for electrochemical energy storage applications

Here in, we report a simple and facile method to synthesis morphology oriented transition metal (Nickel) doped polyaniline (Ni²⁺/PANI) by chemical oxidative polymerization with the assistance of ultrasonic irradiation. Physicochemical property of the materials examined through XRD and FT-IR. The morphological feature exposed that the sonochemical assisted Ni²⁺ doped PANI is differing from the conventional method and it reveals a notable electrochemical property as in the form of specific capacitance (370 F g^-1 at 0.5 A g^-1) with improved rate capability and sustained cycling performance due to its typical interconnected nano-fibrillar morphology than the other synthesized materials. These intriguing features realized from the properly arranged nanostructure with perfect doping and make as a promising candidate as an electrode material in supercapacitor applications.

Preparation and Application of Electrodes in Capacitive Deionization (CDI): a State-of-Art Review

As a promising desalination technology, capacitive deionization (CDI) have shown practicality and cost-effectiveness in brackish water treatment. Developing more efficient electrode materials is the key to improving salt removal performance. This work reviewed current progress on electrode fabrication in application of CDI. Fundamental principal (e.g. EDL theory and adsorption isotherms) and process factors (e.g. pore distribution, potential, salt type and concentration) of CDI performance were presented first. It was then followed by in-depth discussion and comparison on properties and fabrication technique of different electrodes, including carbon aerogel, activated carbon, carbon nanotubes, graphene and ordered mesoporous carbon. Finally, polyaniline as conductive polymer and its potential application as CDI electrode-enhancing materials were also discussed.

Carbon nanotube–polyaniline core–shell nanostructured hydrogel for electrochemical energy storage

Highly porous three-dimensional core (carbon nanotube)–shell (polyaniline) conductive hydrogels synergize the advantageous features of hydrogels and conductive materials, showing enhanced electrical conductivity and electrochemical activity.

Carbons and electrolytes for advanced supercapacitors

Electrical energy storage (EES) is one of the most critical areas of technological research around the world. Storing and efficiently using electricity generated by intermittent sources and the transition of our transportation fleet to electric drive depend fundamentally on the development of EES systems with high energy and power densities. Supercapacitors are promising devices for highly efficient energy storage and power management, yet they still suffer from moderate energy densities compared to batteries. To establish a detailed understanding of the science and technology of carbon/carbon supercapacitors, this review discusses the basic principles of the electrical double-layer (EDL), especially regarding the correlation between ion size/ion solvation and the pore size of porous carbon electrodes. We summarize the key aspects of various carbon materials synthesized for use in supercapacitors. With the objective of improving the energy density, the last two sections are dedicated to strategies to increase the capacitance by either introducing pseudocapacitive materials or by using novel electrolytes that allow to increasing the cell voltage. In particular, advances in ionic liquids, but also in the field of organic electrolytes, are discussed and electrode mass balancing is expanded because of its importance to create higher performance asymmetric electrochemical capacitors.

Ionic liquid directed assembly of wrinkled and porous composite electrode for high-power flexible supercapacitors

By using carbon nanotube/ionic liquid as surfactant-like agent, flexible reduced graphene oxide/polyaniline composite electrode membranes with wrinkled and porous structure were fabricated for high performance supercapacitors.

Conducting polymer composite film incorporated with aligned carbon nanotubes for transparent, flexible and efficient supercapacitor

Polyaniline composite films incorporated with aligned multi-walled carbon nanotubes (MWCNTs) are synthesized through an easy electrodeposition process. These robust and electrically conductive films are found to function as effective electrodes to fabricate transparent and flexible supercapacitors with a maximum specific capacitance of 233 F/g at a current density of 1 A/g. It is 36 times of bare MWCNT sheet, 23 times of pure polyaniline and 3 times of randomly dispersed MWCNT/polyaniline film under the same conditions. The novel supercapacitors also show a high cyclic stability.

An overview of the applications of graphene-based materials in supercapacitors

Due to their unique 2D structure and outstanding intrinsic physical properties, such as extraordinarily high electrical conductivity and large surface area, graphene-based materials exhibit great potential for application in supercapacitors. In this review, the progress made so far for their applications in supercapacitors is reviewed, including electrochemical double-layer capacitors, pseudo-capacitors, and asymmetric supercapacitors. Compared with traditional electrode materials, graphene-based materials show some novel characteristics and mechanisms in the process of energy storage and release. Several key issues for improving the structure of graphene-based materials and for achieving better capacitor performance, along with the current outlook for the field, are also discussed.