Pseudocapacitive Mechanism Research Articles

Intercalation pseudocapacitance mechanism realizes high-performance cathode for aqueous potassium ion batteries

Aqueous potassium-ion batteries have garnered significant interest due to their eco-friendly characteristics and affordability. However, The suboptimal lifetime and restricted energy density of electrode materials present considerable obstacles to the advancement of aqueous potassium ion batteries. In this paper, we report a Ce doped MnO2 material (Ce-MnO2). Ce-MnO2 with large lattice spacing and abundant oxygen defects successfully triggered the intercalation pseudocapacitance behavior in aqueous potassium ion batteries. The intercalation pseudocapacitance mechanism gives MnO2 good capacity and enhanced stability. The Ce-MnO2 demonstrates a high discharge capacity of 120 mAh g−1 at 1 A g−1 with a low concentration electrolyte. It also has a capacity retention rate of 82.5% at 2000 cycles at 5 A g−1. The application of the intercalation pseudocapacitance mechanism offers a new approach to addressing the challenges associated with aqueous potassium-ion batteries.

High electrochemical energy storage device via cation insertion kinetics in Cs3Bi2(Cl0.5I0.5)9@NiO composite electrodes with wide potential window

Surface faradaic process in pseudocapacitor can enable a device that stores higher energy than electrical double-layer capacitors, at higher power delivery than batteries. Yet, most known pseudocapacitive materials exhibit capacitances much less than their predicted values, and possess a low power capability due to their low intrinsic conductivity, in addition to poor cation accessibility. Here, we demonstrate that a bicontinuous Cs3Bi2(Cl0.5I0.5)9@NiO composite electrode is able to operate at rates comparable to those of conventional EDLCs; it provide high gravimetric and area normalized capacitances. We present the design of perovskite based electrode designs with improved ion accessibility to redox-active sites, which delivered up to 487 Fg−1 at scan rates of 10 mVs−1 with exceptionally high specific energy density of ∼270 Wh/kg. The electrode architecture enabled us to achieve excellent capacitance retention and power density up to 194 W/g, at rate of 1.0 Vs-1, with ∼76% contribution from fast surface-controlled (pseudocapacitive) mechanism.

Unlocking the Interfacial Adsorption‐Intercalation Pseudocapacitive Storage Limit to Enabling All‐Climate, High Energy/Power Density and Durable Zn‐Ion Batteries

AbstractSluggish storage kinetics and insufficient performance are the major challenges that restrict the transition metal dichalcogenides (TMDs) applied for zinc ion storage, especially at the extreme temperature conditions. Herein, a multiscale interface structure‐integrated modulation concept was presented, to unlock the omnidirectional storage kinetics‐enhanced porous VSe2−x⋅n H2O host. Theory research indicated that the co‐modulation of H2O intercalation and selenium vacancy enables enhancing the interfacial zinc ion capture ability and decreasing the zinc ion diffusion barrier. Moreover, an interfacial adsorption‐intercalation pseudocapacitive storage mechanism was uncovered. Such cathode displayed remarkable storage performance at the wide temperature range (−40–60 °C) in aqueous and solid electrolytes. In particular, it can retain a high specific capacity of 173 mAh g−1 after 5000 cycles at 10 A g−1, as well as a high energy density of 290 Wh kg−1 and a power density of 15.8 kW kg−1 at room temperature. Unexpectedly, a remarkably energy density of 465 Wh kg−1 and power density of 21.26 kW kg−1 at 60 °C also can be achieved, as well as 258 Wh kg−1 and 10.8 kW kg−1 at −20 °C. This work realizes a conceptual breakthrough for extending the interfacial storage limit of layered TMDs to construct all‐climate high‐performance Zn‐ion batteries.

Unlocking the Interfacial Adsorption-Intercalation Pseudocapacitive Storage Limit to Enabling All-Climate, High Energy/Power Density and Durable Zn-Ion Batteries.

Sluggish storage kinetics and insufficient performance are the major challenges that restrict the transition metal dichalcogenides (TMDs) applied for zinc ion storage, especially at the extreme temperature conditions. Herein, a multiscale interface structure-integrated modulation concept was presented, to unlock the omnidirectional storage kinetics-enhanced porous VSe2-x ⋅n H2 O host. Theory research indicated that the co-modulation of H2 O intercalation and selenium vacancy enables enhancing the interfacial zinc ion capture ability and decreasing the zinc ion diffusion barrier. Moreover, an interfacial adsorption-intercalation pseudocapacitive storage mechanism was uncovered. Such cathode displayed remarkable storage performance at the wide temperature range (-40-60 °C) in aqueous and solid electrolytes. In particular, it can retain a high specific capacity of 173 mAh g-1 after 5000 cycles at 10 A g-1 , as well as a high energy density of 290 Wh kg-1 and a power density of 15.8 kW kg-1 at room temperature. Unexpectedly, a remarkably energy density of 465 Wh kg-1 and power density of 21.26 kW kg-1 at 60 °C also can be achieved, as well as 258 Wh kg-1 and 10.8 kW kg-1 at -20 °C. This work realizes a conceptual breakthrough for extending the interfacial storage limit of layered TMDs to construct all-climate high-performance Zn-ion batteries.

Ultrafine Fe2VO4 nanoparticles anchored on Ti3C2Tx nanosheets (Fe2VO4@Ti3C2Tx) as high-energy anode for lithium-ion storage

Recently, as a new breakthrough for lithium-ion storage anode materials, transition metal vanadates, such as Fe2VO4, have attracted much attention, which, however, still suffer from slow electrochemical kinetics and substantial volume expansion. Hybrid with high conductivity materials is an effective route to deal with these issues. Herein, in situ synthesis of Fe2VO4@Ti3C2Tx composites with porous sandwich structure by co-precipitation-calcination process was reported. Ultrafine Fe2VO4 nanoparticles (10–15 nm) in situ grew and was anchored on Ti3C2Tx nanosheets, which effectively inhibits both the grain growth for Fe2VO4 and stacking for Ti3C2Tx, thus facilitating the electrochemical kinetics and alleviating the volume change of Fe2VO4 to maintain the integrated structure during the cycling process. As a result, Fe2VO4@Ti3C2Tx anode shows high Li+ diffusion coefficient (2.72 × 10−11 cm2 s−1) and pseudocapacitive charge storage mechanism (capacitive charge storage contribution 70.85–84.80 % at 0.2–1.0 mV s−1), which guarantee rapid charging and discharging capability. Consequently, outstanding rate performance (1012–595 mAh g−1 at 0.2–3.0 A g−1) and superior cycling capability (663 and 416 mAh g−1 at 1.0 A g−1 for 200 cycles and 2.0 A g−1 for 500 cycles, with the average capacity attrition rate of 0.059 % and 0.053 %, respectively), were achieved, which render Fe2VO4@Ti3C2Tx composites important potential for lithium-ion storage.

Ethyl viologen-functionalized reduced graphene oxide composites for asymmetric ionic liquid-based supercapacitors

The development of pseudocapacitive materials matching ionic liquid (IL) electrolytes can significantly enhance the performance of supercapacitors (SCs). Herein we report an ethyl viologen-functionalized reduced graphene oxide composite (EV-RGO) synthesized by one-step hydrothermal method. In EV-RGO, the ethyl viologen cations are anchored on the RGO sheets through electrostatic interactions, π-π stacking interactions, and cation-π interactions, which makes EV-RGO as an electrode material more stable and reversible during charging and discharging. Meanwhile, the viologen cations with ethyl groups can better function as a spacer to suppress effectively the stacking of RGO sheets and expand their interlayer spacing. In 1-ethyl-3-methylimidazolium tetrafluoroborate (EmimBF4) IL electrolyte, the electrochemical performance of the composite is enhanced due to synergic contributions from electric double-layer capacitance and pseudocapacitance. The pseudocapacitance mechanism is also supported by the results of XPS data. The specific capacitance of the EV-RGO as a negative electrode material for SCs reaches to 222.7 F g−1 at a current density of 0.5 A g−1. An asymmetric SC device (EV-RGO//AC ASC) exhibits an energy density of 64.1 Wh kg−1 at a power density of 888 W kg−1. This work offers an advanced strategy for the fabrication of high-performance SCs using organic molecule-modified graphene composites.

Localized Ligands Assist Ultrafast Multivalent‐Cation Intercalation Pseudocapacitance

AbstractRechargeable batteries based on multivalent cation (Mvn+, n>1) carriers are considered potentially low‐cost alternatives to lithium‐ion batteries. However, the high charge‐density Mvn+ carriers generally lead to sluggish kinetics and poor structural stability in cathode materials. Herein, we report an Mvn+ storage via intercalation pseudocapacitance mechanism in a 2D bivalve‐like organic framework featured with localized ligands. By switching from conventional intercalation to localized ligand‐assisted‐intercalation pseudocapacitance, the organic cathode exhibits unprecedented fast kinetics with little structural change upon intercalation. It thus enables an excellent power density of 57 kW kg−1 over 20000 cycles for Ca2+ storage and a power density of 14 kW kg−1 with a long cycling life over 45000 cycles for Zn2+ storage. This work may provide a largely unexploited route toward constructing a local dynamic coordination microstructure for ultrafast Mvn+ storage.

Localized Ligands Assist Ultrafast Multivalent-Cation Intercalation Pseudocapacitance.

Rechargeable batteries based on multivalent cation (Mvn+ , n>1) carriers are considered potentially low-cost alternatives to lithium-ion batteries. However, the high charge-density Mvn+ carriers generally lead to sluggish kinetics and poor structural stability in cathode materials. Herein, we report an Mvn+ storage via intercalation pseudocapacitance mechanism in a 2D bivalve-like organic framework featured with localized ligands. By switching from conventional intercalation to localized ligand-assisted-intercalation pseudocapacitance, the organic cathode exhibits unprecedented fast kinetics with little structural change upon intercalation. It thus enables an excellent power density of 57 kW kg-1 over 20000 cycles for Ca2+ storage and a power density of 14 kW kg-1 with a long cycling life over 45000 cycles for Zn2+ storage. This work may provide a largely unexploited route toward constructing a local dynamic coordination microstructure for ultrafast Mvn+ storage.

Cation-deficient T-Nb2O5/graphene Hybrids synthesized via chemical oxidative etching of MXene for advanced lithium-ion capacitors

Orthorhombic niobium pentoxide (T-Nb2O5) is widely acknowledged as a fast pseudocapacitive material. Nevertheless, its application is hindered by the narrow voltage window (1–3 V vs. Li/Li+) that arises from irreversible phase transformation and sluggish kinetics during deep lithiation. Herein, we demonstrate a unique method for introducing Nb vacancies in T-Nb2O5 nanoparticles via amine-assisted oxidative etching of Nb2CTx MXene, providing extra storage sites and improving structural flexibility by introducing cationic defects. Subsequently reduced graphene oxide (rGO) is employed as substrate to disperse T-Nb2O5 nanoparticles and construct T-Nb2O5/rGO nanohybrids. Multiple characterizations and computational simulations demonstrate that the resulting T-Nb2O5/rGO hybrid anode exhibits rapid and stable multi-electron transfer lithium storage. Owing to the enrichment of Nb vacancies and nanoparticle morphology, even when voltage window of 0.01–3 V (vs. Li/Li+) is extended, T-Nb2O5 exhibits a pseudocapacitive mechanism and integrity of partial crystal structure; effectively tackling the structural collapse and sluggish kinetics of T-Nb2O5. Consequently, the T-Nb2O5/rGO anode shows a superior rate capacity (148 mAh/g at 10 A/g) and cycling stability (3000 cycles at 5 A/g). Remarkably, the assembled lithium-ion capacitors achieve a high energy density of 123.7 Wh/kg, a power density of 22.5 kW/kg, and a capacity retention of 83.6% after 20,000 cycles.

Understanding Pseudocapacitance Mechanisms by Synchrotron X‐ray Analytical Techniques

Pseudocapacitive materials that store charges via reversible surface or near‐surface faradaic reactions are capable of overcoming the capacity limitations of electrical double‐layer capacitors. Revealing the structure–activity relationship between the microstructural features of pseudocapacitive materials and their electrochemical performance on the atomic scale is the key to build high‐performance capacitor‐type devices containing ideal pseudocapacitance effect. Currently, the high brightness (flux), and spectral and coherent nature of synchrotron X‐ray analytical techniques make it a powerful tool for probing the structure–property relationship of pseudocapacitive materials. Herein, we report a comprehensive and systematic review of four typical characterization techniques (synchrotron X‐ray diffraction, pair distribution function [PDF] analysis, soft X‐ray absorption spectroscopy, and hard X‐ray absorption spectroscopy) for the study of pseudocapacitance mechanisms. In addition, we offered significant insights for understanding and identifying pseudocapacitance mechanisms (surface redox pseudocapacitance, intercalation pseudocapacitance, and the extrinsic pseudocapacitance phenomenon in battery materials) by combining in situ hard XAS and electrochemical analyses. Finally, a perspective for further depth of understanding into the pseudocapacitance mechanism using synchrotron X‐ray analytical techniques is proposed.

FeSe2/TiO2 heterostructure as an efficient photocatalyst and their electrochemical energy storage applications

This paper reported the facile synthesis of FeSe2 and TiO2 and their different wt.% composites (75 and 50% of TiO2, here after FT-1 and FT-2) via solvothermal in/ex-situ sol-gel method for the first time efficient photocatalytic degradation of Rhodamine removal and supercapacitor applications. Small bandgap energy was obtained for FT-1 samples from the optical analysis, with a more negligible band edge absorption. The result shows that the composite of FeSe2 and TiO2 increases the absorption, which collectively enhances the separation of the charge carriers and redox activities. The photocatalytic activities analysis demonstrated that the FT-1 sample reveals the fastest removal of the RB dye in just 60 min (FT-2, FeSe2, and TiO2 = 90, 100, and 180 min) with good stability (98%) after several cycles. As supercapacitor electrode materials, all electrodes showed well-defined peaks in their CV loops and voltage plateaus in their charge/discharge profile, illustrating the pseudocapacitive charge storage mechanism. No voltage decay was observed during many discharge currents from the charge/discharge investigation, demonstrating the chosen potential frame is a suitable window for the FeSe2 and TiO2 nanomaterials. The higher capacity of 295 (FT-1) than other electrodes (FeSe2, TiO2, and FT-2 = 220, 115, and 240 C/g) at 1 A/g was obtained to reach 180 at 10 A/g, resulting in an enhanced rate capability of 82%. The high rate capability is the cause of its more minor charge transfer resistance, resulting in higher conductivity and supporting rapid charge transport kinetics. These outstanding properties open a new avenue for other FeSe2 and TiO2 nanomaterials for efficient energy storage technologies.

Electrochemical insights into the energy storage mechanism of birnessite in aqueous solutions

The birnessite structure of manganese dioxide makes this compound a promising electrode materials for energy storage devices including, in particular for supercapacitors, thanks to the high theoretical capacitance and pseudocapacitive response of MnO2. The effect of ionic species, in particular alkali cations, on the structure of birnessite has been intensively discussed, however their role on the charge storage mechanism is still controversial. Taking into consideration the solvation/desolvation process of different alkali cations (Li+, Na+, K+ and Cs+), this work unveils relevant new aspects of the pseudocapacitive charge storage mechanism of birnessite. The work also discusses the simultaneous contribution of non-faradaic (double-layer processes) and faradaic redox reactions to the charge storage mechanism based on electrochemical impedance spectroscopy (EIS) analysis. It was found that the relative extension of these processes was dependent on diffusional features related to the cation degree of solvation. Results revealed that the potassium birnessite exhibited an interesting specific capacitance value that reached 175.6 F g−1 at 0.5 A g−1 in a potential window of 0.8 V in 0.5 M Li2SO4. This capacitance value includes a contribution resulting from intercalation/deintercalation of cations in the interlayer region and a larger contribution from the double-layer processes (above 76%). This investigation provides new electrochemical insights on the charge storage of birnessite, highlighting the role of alkali ions intercalation in the interlayer structure of birnessite.

High‐rate sodium‐ion storage of vanadium nitride via surface‐redox pseudocapacitance

AbstractVanadium nitride (VN) electrode displays high‐rate, pseudocapacitive responses in aqueous electrolytes, however, it remains largely unclear in nonaqueous, Na+‐based electrolytes. The traditional view supposes a conversion‐type mechanism for Na+ storage in VN anodes but does not explain the phenomena of their size‐dependent specific capacities and underlying causes of pseudocapacitive charge storage behaviors. Herein, we insightfully reveal the VN anode exhibits a surface‐redox pseudocapacitive mechanism in nonaqueous, Na+‐based electrolytes, as demonstrated by kinetics analysis, experimental observations, and first‐principles calculations. Through ex situ X‐ray photoelectron spectroscopy and semiquantitative analyses, the Na+ storage is characterized by redox reactions occurring with the V5+/V4+ to V3+ at the surface of VN particles, which is different from the well‐known conversion reaction mechanism. The pseudocapacitive performance is enhanced through nanoarchitecture design via oxidized vanadium states at the surface. The optimized VN‐10 nm anode delivers a sodium‐ion storage capability of 106 mAh g−1 at the high specific current of 20 A g−1, and excellent cycling performance of 5000 cycles with negligible capacity losses. This work demonstrates the emerging opportunities of utilizing pseudocapacitive charge storage for realizing high‐rate sodium‐ion storage applications.

Surface redox pseudocapacitance-based vanadium nitride nanoparticles toward a long-cycling sodium-ion battery

Structure-stable anodes are essential for achieving long-cycling stability in sodium-ion batteries. However, a large cycled structure/volume change is inevitable in conversion-type or alloying-reaction anodes, which make them intrinsically unsuitable for durable sodium-ion batteries . Here, we synthesized carbon fiber-anchored vanadium nitride nanoparticles (denoted as VN@CF) through a simple molten-salt method without NH3 treatment. The VN@CF anode shows an ultra-stable Na-storage structure with a discharge capacity of 204 mAh/g at 0.1 A/g after 500 cycles. More notably, it shows remarkably long-cycling stability over 6600 cycles without capacity attenuation at 1.0 A/g. Multiple ex-situ characterizations, such as X-ray diffraction and X-ray photoelectron spectroscopy, indicate that the sodium storage behavior of VN@CF is a surface redox-related pseudocapacitive process, which is further supported by theoretical calculations. Such surface pseudocapacitive could not only enhance the sodium-storage structure stability but increase the redox reaction kinetics, which should be the origins of VN@CF's superior electrochemical properties. Our work paves a way for designing structure-stable energy storage materials based on the surface redox pseudocapacitance mechanism.

Boosting Pseudocapacitive Behavior of Supercapattery Electrodes by Incorporating a Schottky Junction for Ultrahigh Energy Density

HighlightsIncorporation of Schottky Junction increases the pseudocapacitive mechanism at higher current rate.The pseudocapacitance behavior of the positive and negative electrodes is balanced to construct a solid-state supercapattery device.An energy density of 236.14 Wh kg−1 is achieved for solid-state supercapattery device.

High Proportion of Active Nitrogen-Doped Hard Carbon Based on Mannich Reaction as Anode Material for High-Performance Sodium-Ion Batteries.

The potential for energy storage in carbonaceous materials is well known. Heteroatom doping - particularly nitrogen doping - can further enhance their electrochemical performance. The type of N configuration determines the reactivity of doped carbon. It remains a challenge, however, to achieve a high ratio of active N (N-5) in N-doped carbon. In this study, a high proportion of active nitrogen-doped hard carbon (PTA-Lys-800) is synthesized by the classical Mannich reaction, using tannic acid (TA) and amino acid as precursors. For sodium-ion batteries (SIBs), PTA-Lys-800 provides outstanding cycling stability and rate performance (338.8 mAh g-1 at 100 mA g-1 for 100 cycles, a capacity retention of 86 %; 131.1 mAh g-1 at 4 A g-1 after 5000 cycles). The excellent performance of PTA-Lys-800 is attributed to stable hierarchical pore structure, abundant defects, and a high proportion of N-5 formed during the carbonization process. Based on a detailed fundamental analysis, the pseudocapacitance mechanism is found to contribute to the higher sodium storage process in PTA-Lys-800. The Na-adsorption mechanism is further explored through ex situ Raman spectroscopy. A new method is presented for designing carbonaceous anode materials with high capacity and long cycle life.

Phytic acid-doped and ammonium hydroxide de-doped polyaniline cathodes for rechargeable aluminum ion battery

Rechargeable aluminum ion battery (RAIB) is a very promising large-scale energy storage scheme attributed by the advantages of aluminum with large theoretical capacity, high energy density, low cost, abundant earth resources and environment friendliness. The selection and preparation of cathode materials are crucial for the electrochemical performance of RAIB. In this study, the specific capacity and cycle life of RAIB were improved by using polyaniline doped with phytic acid and further optimized by ammonium hydroxide de-doping treatment. Phytic acid doping improves the spatial configuration of polyaniline, making the nanostructure more hierarchical and increasing the specific surface area. More importantly, ammonium hydroxide treatment provides more chemical reaction sites while maintaining hierarchic structural morphology of the material. Due to the advantages above, the de-doped polyaniline cathode obtains an initial discharge-specific capacity of the initial cycle is 78.1 mAh g−1 at a high current density of 1 A g−1. After cycling of 2000, the capacity loss is only 16.7%, and an average decay rate of 0.007% per cycle with the Coulomb efficiency remains about 100% after cycling of 5000. At the same time, the contribution of pseudo capacitance and working mechanism are investigated. The capacity contribution of RAIB has been divided into diffusion-control, surface-control and double-layer, which is more consistent with the actual situation and further deepens the understanding of the charging-discharging mechanism of RAIB. These results are expected to lay a foundation for the future development of RAIB systems for large-scale energy storage using organic polymers as cathode materials.

Hydrothermal assisted synthesis of hierarchical SnO2 micro flowers with CdO nanoparticles based membrane for energy storage applications

Hierarchical nanostructures with appropriate morphology and surface functionalities are highly desired to achieve an optimized electrochemical property for active electrode materials. This work renders the facile hydrothermal synthesis of CdO, SnO2, and CdO–SnO2 nanocomposite, and their capacitive performance was tested. The formation of the pure samples and their composite was committed by low-temperature Raman spectroscopy and x-ray diffraction studies which revealed the tetragonal and cubic structures of CdO and SnO2 powder samples with good crystallinity and purity. The morphological postmortem reveals the formation of nanoparticles morphology of CdO with a highly smooth surface appearance. Besides, the SnO2 illustrates the morphology of the micro flowers composed of ultrathin nanosheets. More specifically, the electrochemical properties indicate the pseudocapacitive charge storage mechanism based on cyclic voltammetry and chronopotentiometry analysis. The CdO–SnO2 composite electrode displayed a higher capacitance due to additional pores/space offered for active sites and continuously allowed electrolyte ions to interact with the inner/outer surface of the electrode. These exciting findings led us to design and fabricate battery hybrid supercapacitors (BHSC) from CdO–SnO2, and activated carbon (AC), referred to as CdO–SnO2//AC BHSC, attains a high power delivery (5717 W/kg), and a maximum energy density of 42 Wh/kg at low discharge rate. Noteworthy, a stable cycling performance was obtained with only 91.3% retention after 8000 cycling at a large discharge current of 10 A/g, denoting the magnificent durability of the active electrode material.

Ag@Fe3O4 nanoparticles decorated NrGO nanocomposite for supercapacitor application

There is still a great need for production and design of electrode materials with superior electrochemical properties for supercapacitor application. Nanocomposites containing graphene-based metal-metal oxide nanostructures are promising electrode materials because of their high conductivity, excellent surface properties, and effective charge storage with both EDLC and pseudocapacitance mechanisms. In this study, Ag@Fe3O4 core@shell nanoparticles decorated nitrogen doped reduced graphene oxide (NrGO) was obtained with a facile and simple method. On the surface of NrGO nanosheets, Ag nanoparticles were found to be coated with Fe3O4 nanoparticles with a particle size of 5–12 nm. The electrochemical measurements of NrGO-Ag@Fe3O4 nanocomposite were carried out in a two-electrode cell. The ternary nanocomposite exhibited 212.2 F/g specific capacitance at a current density of 1 A/g, as well as high cyclic stability, the NrGO-Ag@Fe3O4 nanocomposite retained 77 % of its specific capacitance after 10,000 cycles. The Ag@Fe3O4 decorated NrGO nanocomposite indicates great potential as an electrode material for supercapacitor applications.

Fabrication of Coral-like Polyaniline/Continuously Reinforced Carbon Nanotube Woven Composite Films for Flexible High-Stability Supercapacitor Electrodes

The electrochemical performance is significantly influenced by the structure and surface morphology of the electrode materials used in supercapacitors. Using the floating catalytic chemical vapor deposition (FCCVD) technique, a self-supporting, flexible layer of continuously reinforced carbon nanotube woven film (CNWF) was developed. Then, polyaniline (PANI) was formed in the conductive network of CNWF using cyclic voltammetry electrochemical polymerization (CVEP) in various aqueous electrolytes to produce a series of flexible CNWF/PANI composite films. The impacts of the CVEP period, electrolyte type, and electrolyte concentration on the surface morphology, doping degree, and hydrophilicity of CNWF/PANI composite films were thoroughly examined. The CNWF/PANI1-15C composite electrode, which was created using 15 cycles of CVEP in a solution of 1 M sodium bisulfate, displayed a distinctive coral-like PANI layer with a well-defined sharp nanoprotuberance structure, a 48% doping degree, and a quick reversible pseudocapacitive storage mechanism. At a current density of 1 A g-1, the energy density and specific capacitance reached 54.9 Wh kg-1 and 1098.0 F g-1, respectively, with a specific capacitance retention rate of 75.9% maintained at 10 A g-1. Both the specific capacitance and coulomb efficiency were maintained at 96.9% and more than 98.1% of their initial values after being subjected to 2000 cycles of galvanostatic charge and discharge, demonstrating excellent electrochemical cycling stability. The CNWF/PANI1-15C composite film, an ideal electrode material, offers a promising future in the field of flexible energy storage due to its exceptional mechanical properties (127.9 MPa tensile strength and 16.2% elongation at break).