Supercapacitor Electrode Research Articles

Cellulose intercalation activation of natural ramie fiber derived carbon electrode for flexible supercapacitors

The complex structure of cellulose leads to its low accessibility to reagents, which hinders the further development of cellulose-based natural fibers in supercapacitors. The key issue is how to achieve deep internal activation while maintaining the flexible self-supporting skeleton structure of cellulose. In this work, an intercalation activation method was proposed. The activator infiltrated into the cellulose microcrystalline structure under rapid swelling to construct a new hydrogen bond network. RC/N2 has a large specific surface area (1897 m2 g−1) and exhibits excellent electrochemical performance due to the uniform activation of NaOH pre-inserted between cellulose layers while ensuring the flexibility of cellulose. At a current density of 0.1 A g−1, it reaches 352 F g−1, and the assembled symmetric supercapacitor has a capacitance retention rate of 98 % after 70,000 cycles. In addition, the symmetric flexible supercapacitor assembled based on RC/N2 has good stability after multi-angle bending, which opens up further possibilities for the development of flexible energy storage devices.

Preparation by Wet-spinning and Properties Polyaniline-Polyethersulfone Fibers for Flexible Supercapacitor Electrodes

Preparation by Wet-spinning and Properties Polyaniline-Polyethersulfone Fibers for Flexible Supercapacitor Electrodes

Tin sulfide dendritic hybrids enhanced by metallic carbon nanotubes for superior supercapacitor performance

This study presents a facile, one-step solvothermal approach to enhance the performance of SnS2-based supercapacitor electrodes through the incorporation of metallic single-walled carbon nanotubes (m-SWNTs) via a one-step solvothermal method. The resulting dendritic heterostructures exhibit significantly improved electrochemical properties compared to pristine SnS2. Comprehensive characterization using XRD, XPS, FE-SEM, and BET analysis reveals that m-SWNT incorporation leads to a significant 111.3 % increase in specific surface area and a 255.1 % increase in pore volume for the optimized SNSC5 sample. This structural modification translates to enhanced electrochemical performance, with SNSC5 demonstrating a high specific capacitance of 161 F.g−1 at 1 A.g−1, excellent cyclic stability (94.2 % retention after 5000 cycles), and a high power density of 84.7 Wkg−1. The synergistic effect of the dendritic morphology and m-SWNT network facilitates improved electron transport and ion accessibility. Furthermore, a symmetric solid-state supercapacitor device based on SNSC5 successfully powered LEDs when charged by a solar panel, showcasing its potential for practical energy storage applications. This work provides valuable insights into the design of high-performance electrode materials for next-generation supercapacitors.

Highly conducting Laser-Induced Graphene-Ag nanoparticle composite as an effective supercapacitor electrode with anti-fungal properties

This study presents a simple and an environmentally friendly approach to make Laser-Induced Graphene (LIG) based supercapacitor electrodes anchored with abundant Silver Nanoparticles (AgNPs). LIG, was synthesized using a CO2 laser writing technique on polyimide substrate. The LIG-Ag composite was prepared using two techniques, drop-coating, and screen-printing. Ag nanoparticles prepared using the plant extract of Swietenia Macrophylla was utilized to drop-coat AgNP on LIG substrate. Screen-printing was done by using a commercial Ag-ink and a suitable mesh. The supercapacitor made from screen-printed electrodes and supercapacitor made form drop-coated electrodes showed a high specific capacitance of 118 mF/cm2, 38 mF/cm2, and a high energy density of 2.42 mWh/cm2, 0.05 mWh/cm2 respectively. The screen-printed composite of LIG and AgNP was further studied for its anti-fungal properties and proved to be effective against Candida sp.

Enhancing activated carbon supercapacitor electrodes using sputtered Cu-doped BiFeO3 thin films

This work describes the fabrication of a composite supercapacitor electrode made of Cu-doped BiFeO3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_3$$\\end{document} (Cu-BFO) films on an activated carbon (AC) electrode using radio-frequency (RF) magnetron sputtering. To prevent exfoliation of Cu-BFO and AC upon immersion in an electrolyte, the nickel foam sandwiching electrode technique was introduced. The Cu-BFO films significantly enhanced electrochemical properties, increasing specific capacitance by up to 151% compared to that of an AC electrode. This was attributed to Faradaic reactions and specific surface area in the Cu-BFO/AC electrode. The highest specific capacitance achieved was 169 F g-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {g}^{-1}$$\\end{document} at 0.5 A g-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {g}^{-1}$$\\end{document} , and cycling stability retention was 93.12% after 500 cycles. However, the remaining percentage of the specific capacitance decreased differently with increasing thickness, which is also discussed. Furthermore, an asymmetric supercapacitor using Cu-BFO/AC and AC electrodes demonstrated a high energy density of 4.71 Wh kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {kg}^{-1}$$\\end{document} , power density of 2.66 kW kg-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {kg}^{-1}$$\\end{document}, and over 90% retention after 1000 cycles, highlighting its durability. The uniform RF magnetron sputtering deposition is vital for mass production. Combined with impressive retention in asymmetric supercapacitors, this scalability suggests a promising pathway for large-scale manufacturing. Consequently, this work could pave the way for the large-scale production of supercapacitors.

Trichosanthes Cucumerina Derived Activated Carbon: The Potential Electrode material for High Energy Symmetric Supercapacitor

AbstractHigh surface area porous activated carbons obtained from sustainable biomass are excellent functional materials for energy storage applications. This is the first report on snake gourd (Trichosanthes cucumerina) pericarp as a raw material of activated carbon and supercapacitor electrode material. Herein, a simple KOH activation and carbonisation method is used. The obtained SGC900 sample has a surface area of 1841 m2/g and an average pore volume of 0.52 cm3/g. SGC900 based supercapacitor exhibits good electrochemical storage capacity in 1 M H2SO4 with a specific capacitance of 206 F/g at 1 A/g. The symmetric device delivered an energy density of 11 Wh/kg at a power density of 1.6 kW/kg. It provides a series resistance (Rs) of 1.2 Ω and a charge transfer resistance Rct of 1.9 Ω. Furthermore, the device retains 95 % of capacitance over 5000 cycles. This work presents an easy and feasible approach for producing value‐added activated carbon from sustainable biomass, potentially used in high‐performance energy storage.

Covalent Organic Framework Derived Oxygen/Sulfur-Doped Porous Carbon for Robust High-Capacitance Symmetric Supercapacitors.

Heteroatom-doped porous carbons (HPCs) have been considered promising electrode materials for supercapacitors due to their improvement of energy density by providing extra pseudocapacity. Covalent organic frameworks (COFs) are obtaining great importance in energy storage because of their designable structure and versatile functionality. Herein, we designed and fabricated oxygen and sulfur dual-doped covalent organic framework (COF) derived HPCs with very high heteroatoms content (up to 25.76 atom%) via a facile coupling reaction. The optimized HPCs exhibit a porous structure with high specific surface area (up to 2835 m2 g-1) along with a high specific capacitance (430 F g-1 at 0.5 A g-1), excellent capacitance retention (96.9%), and high coulombic efficiency (98.5%) after 10000 cycles at 5 A g-1. As electrodes for aqueous symmetric supercapacitors, the HPCs exhibits a high energy density of 60 Wh kg-1 at a 250 W kg-1 power density, excellent cycling stability of capacity retention (82.2%) and a high coulombic efficiency (92.3%) after 10000 cycles at 10 A g-1, indicating attractive application potential in chemical energy storage. This work establishes a promising strategy for preparation of high heteroatom content HPCs using COFs and demonstrates great potential for energy storage/conversion devices.

Tuning properties of binary functionalization of Sc2C MXenes for supercapacitor electrodes

Surface functionalization of two-dimensional (2D) materials like Sc2C MXenes offers a promising avenue for tailoring their properties for various applications. At the same time, significant research has focused on pure terminations involving oxygen (-O), fluorine (-F), or hydroxyl (-OH) groups. Binary surface functionalization still needs to be explored. Our work addresses this gap by investigating binary functionalized Sc2C monolayers, specifically Sc2CFN and Sc2COS. Using first-principles calculations, we explore the structural, electronic, and quantum capacitance (CQ) properties of pristine Sc2C and functionalized Sc2CFN and Sc2COS. The CQ measurements reveal distinctive electronic behaviour, with Sc2CFN and Sc2COS exhibiting indirect bandgaps of 0.90 and 1.48 eV, respectively. Introducing functional groups induces a metal-to-semiconductor transition, enhancing charge storage at the cathode and increasing the CQ to 371.64 and 341.23 μF/cm2 for Sc2CFN and Sc2COS, respectively. As far as energy applications are concerned, we also calculate the Shockley-Queisser (SQ) efficiency, which is a widely accepted quantity to get an estimate of the photovoltaic efficiency of 28.77 % for Sc2CFN and 32.97 % for Sc2COS materials. Additionally, we analyze the current-voltage (IV) characteristics, uncovering negative differential conductance (NDC) effects in Sc2COS, indicative of its potential for fast molecular switching applications. Our study provides valuable insights into the properties of binary functionalized Sc2C MXenes, paving the way for their utilization in energy storage and nanoelectronic devices.

In-Situ Preparation of Iron(II)-phthalocyanine@multi-Walled-CNTs Nanocomposite for Quasi-Solid-State Flexible Symmetric Supercapacitors with Long Cycling Life.

The construction of supercapacitor electrode materials with exceptional performance is crucial to the commercialisation of flexible supercapacitors. Here, a novel in-situ precipitation technique was applied for constructing iron(II)-phthalocyanine (FePc) based nanocomposite as the electrode material in quasi-solid-state flexible supercapacitors. The highly redox-active FePc nanostructures were grown in the multi-walled-CNTs (MWCNTs) networks, which shows convenient electron/electrolyte ion transport pathways along with outstanding structural stability, leading to high energy storage and long cycling life. The electrode of FePc@MWCNTs delivered a higher specific capacity than that of individual MWCNTs and FePc. The quasi-solid-state symmetric flexible device that was constructed using FePc@MWCNTs electrode demonstrated impressive performance with a maximum energy density of 29.7 Wh kg-1 and a maximum power density of 4000 W kg-1. Moreover, the device demonstrated superior durability and flexibility, as evidenced by its exceptional cyclic stability (111.3 %) even after 30000 cycles at 8 A g-1. These results reveal that the FePc@MWCNTs nanocomposite prepared by this simple in-situ precipitation method is promising as electrode material for next-generation flexible wearable power sources.

Role of synthetic process parameters of nano-sized cobalt/nickel oxide in controlling their structural characteristics and electrochemical energy performance as supercapacitor electrodes

The synthesis of nano-sized bimetallic Cobalt/Nickel oxides (Ni1.5Co1.5O4) with a 1:1 Co/Ni atomic ratio has been achieved using a surfactant-free co-precipitation/hydrothermal process. The growth mechanism of Cobalt/Nickel oxides Ni1.5Co1.5O4 is elucidated by tuning the synthesis process parameters, including co-precipitation pH and hydrothermal time. The formation of Cobalt/Nickel oxides Ni1.5Co1.5O4 oxide began with the nucleation of cobalt nickel hydroxide nanoplates through the co-precipitation process, followed by dissolution-recrystallization, stacked hexagonal nano-flakes, and a flower-like microstructure. The electrochemical performances of the oxides were evaluated, with the largest surface area observed at pH 9 being the main factor for the best super-capacitive performance. As hydrothermal time increased, the structural directing growth forward, resulted in the formation of a nano-flower structure with a larger surface area. The as-prepared cobalt nickel oxide exhibited a maximum specific capacitance value of 525.5 F g-1 at a current density of 1 A g-1 and energy and power densities of 88.2 WhKg-1 and 606 WKg-1, respectively.

One-Step Synthesis of NiCo-LDH@Ni(OH)2 Heterostructure Foams on Biomass-Derived Porous Carbon for High-Performance Supercapacitors.

Layered double hydroxides (LDHs) have attracted much attention as pseudocapacitor supercapacitor electrodes because of their high theoretical specific capacity. However, LDHs have drawbacks such as poor electrical conductivity, and their specific capacities are lower than the theoretical values. In this work, NNCLDH@OPC electrodes are constructed via in situ synthesis of heterostructure foams (NNCLDH) consisting of NiCo-LDH and Ni(OH)2 on pomelo peel-derived porous carbon (OPC) through a one-step solvothermal method using ZIF-67 as a template. Owing to the synergistic effect of the 3D nanofoam structure and the multicomponent heterostructure as well as the conductive porous carbon support, the NNCLDH/OPC exhibited ultrahigh electrochemical performance as well as excellent cycling stability: a specific capacity of 3290 F g-1 at 1 A g-1 and a capacitance retention of 77.8% after 4000 cycles at a current density of 10 A g-1. In addition, the assembled NNCLDH@OPC//OPC asymmetric supercapacitor (ASC) has a maximum energy density of 51Wh kg-1 with a power density of 812W kg-1 and a maximum power density of 16kW kg-1 at a current density of 20 A g-1. These results demonstrate the significant application potential of NNCLDH/OPC composites in supercapacitor electrodes.

Novel asymmetrical oxime ligand-based coordination compounds in conducting copolymer as a useful electrodes for electrochemical supercapacitors

Novel asymmetrical oxime ligand-based coordination compounds in conducting copolymer as a useful electrodes for electrochemical supercapacitors

Enhanced Electrochemical Performance of Highly Porous CeO2-Doped Zr Nanoparticles for Supercapacitor Applications.

The aim of this work was to develop an ultrasonic-assisted synthesis method for the fabrication of CeO2-doped Zr nanoparticles that would improve the performance of supercapacitor electrodes. This method, which eliminates the need for high-temperature calcination, involves embedding CeO2 into Zr nanoparticles through 1 hr (CeO2-Zr-1) and 2 hrs (CeO2-Zr-2) of ultrasonic irradiation, resulting in the formation of nanostructures with significant improvements in their electrochemical properties. Through physicochemical analysis, we observed that the CeO2-doped Zr nanoparticles, particularly those treated for 2 hrs (CeO2-Zr-2), exhibit superior crystalline phase purity, optimal chemical surface composition, minimal agglomeration with particle sizes below 50 nm, and an impressive average surface area of 178 m2/g. Compared to the 1 hr irradiation samples (CeO2-Zr-1) and undoped CeO2 nanoparticles, the (CeO2-Zr-2) electrodes demonstrated a remarkable capacitance of 198 Fg-1 at a current density of 1 A/g while maintaining ~94.9% of their capacity after 3750 cycles. This indicates not only good reversibility but also exceptional stability. In (CeO2-Zr-2) samples, the nanospherical structure achieved through ultrasonic synthesis is responsible for the enhanced capacitive behavior and stability, along with the synergistic effects caused by Zr doping, which improves the CeO2 nanoparticle conductivity to a significant extent. Surface areas of the electrodes are larger due to the combination of these two materials, which contribute to their superior performance.

Neutral-state black electrochromic polymer with enhanced supercapacitor electrode performance

Neutral-state black electrochromic materials are attracting attention, especially in the applications of displays, car-rear views, sensors, and electronic papers. This study aimed to obtain a black electrochromic polymer via electrochemical techniques. For this aim, the monomer of a green-electrochromic polymer, 4-(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-7-(3,3-dihexyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-8-yl)-2-cyclohexyl-2H-benzo-[d]imidazole (PBP), was copolymerized with 3,4-ethylenedioxythiophene (EDOT) with 2:1 and 2:2 (PBP: EDOT) monomer feed ratios. The resulting copolymer films were investigated in terms of their electrochromic properties. Equal feeded copolymerization resulted in a neutral-state black electrochromic polymer (L:11.5, a:1.5, b:-2.55) with satisfying responses in the electrochromic device application (100 % electroactivity maintenance after 300 switches with 1.4 s response time). Furthermore, increasing the quantity of EDOT in the copolymer chain improved the capacitive characteristics, showing that the equal-fed copolymer is a good candidate for a supercapacitor electrode (4.07 mF/cm2). The supercapacitor device application showed that the equal feeded copolymer has superior specific capacitance retention of 97 % after 500 charge/discharge cycle, with 100 % coulombic efficiency in each cycle. Moreover, the supercapacitor is capable of lighting a 1.5 V LED for >30 s.

Microwave assisted activation of silkworm excrement for fast adsorption of methylene blue and high performance supercapacitor

The activated carbon (AC) with an exceptionally high surface area was made of silkworm excrement (SE) by microwave-assisted KOH activation (MAKA). It was investigated for the potential applications in methylene blue (MB) adsorption and a supercapacitor electrode. The effect of activation time on the AC properties and performance was studied. The physical and chemical properties of the as-prepared samples were analyzed by FE-SEM, TEM, N2 adsorption, and Raman spectroscopy. Remarkably, the AC with the largest specific surface area (SAs) of 2530.3 m2g−1 was produced by partial carbonization of SE at 400 °C (SE400-5) and then activated for only 5 min. The large SAs is attributed to the abundance of micro-pores, leading to the enhanced MB absorption performance, as equilibrium was reached within 10 min at 25 ppm of MB concentration. The maximum MB adsorption capacity for SE400-5 was 902.56 mg g−1. The adsorption isotherms revealed that the Langmuir model best fits the empirical data (R2 ≥ 0.9813), indicating monolayer adsorption. The kinetic model fitted well to the Pseudo-second-order (PSO) (R2 ≥ 0.9691). CV, GCD, and EIS measurements also evaluated the electrochemical properties of all samples. The electrodes were made without the addition of conductive material. The SE400-5 also had the lowest total resistance and highest total effective capacitance, which resulted in its highest specific capacitance (Cs) of 322 F g−1 at 0.5 A g−1. The capacitive retention of SE400-5 remained as high as 98% even after 10,000 cycles at 10 A g−1. These results demonstrate that SE is a viable source of AC for MB adsorption and a supercapacitor electrode.Graphical abstract

A Minireview of Multimetallic Iron‐Based Oxides for Supercapacitive Negative Electrode Materials

The serious mismatch between the positive and negative electrodes of supercapacitors (SCs) makes it imperative to develop high‐performance negative electrode materials. Among them, multimetallic iron‐based oxides (MIBOs) are intensively investigated attributed to their high theoretical specific capacitance, wide operating potential window, copious electrochemical active sites, variable metal oxidation states, and abundant redox centers. This paper briefly introduces some essential information on SCs and the most common synthesis methods of MIBOs. Also, the research progress of several important MIBOs and their composites is discussed. Finally, the existing problems and challenges of MIBOs are summarized and future outlooks are likewise proposed.

High‐Performance Supercapacitor Electrodes Based on Porosity‐Controllable Carbon Paper by Centrifugal Spinning

Carbon paper is widely utilized in supercapacitors primarily for its notable attributes, including high specific surface area, commendable electrical conductivity, and excellent chemical stability. Then investigate the effect of carbon paper with different porosities as supercapacitor substrates on the electrochemical performance of electrodes. Meanwhile, tungsten oxide is grown on the surface of carbon paper using the hydrothermal method to test the electrochemical performance of the composite electrode. The prepared carbon paper and oxygen‐deficient tungsten oxide (WOx) composite electrode (CP@WOx) exhibit an area‐specific capacitance of 915.8 mF/cm² at a current density of 5 mA/cm². In addition, the electrode exhibits good cycling stability. After 20,000 cycles, the capacitance remains 104.1% of the original capacity at 50 mA/cm² current density. Solid‐state symmetric supercapacitors assembled using CP@WOx electrode exhibit excellent performance in terms of surface energy density of 6.25 µWh/cm2(at a power density of 0.6 mW/cm2) and maintain 100.4% of their original capacity after 7000 charge/discharge cycles. Relying on the higher productivity advantage of centrifugal spinning technology over electrostatic spinning technology and other preparation processes, this study develops a new way of thinking for the large‐scale production of composite electrode materials, which has more considerable potential for large‐scale development.

Zeolitic imidazolate framework@graphene oxide nanocomposites for efficient supercapacitor electrodes

Despite advancements in nanoscale electrode materials, the pursuit of dependable, effective, and environmentally sound supercapacitors continues. This study explores the potential of zeolitic imidazolate framework@graphene oxide (ZIF@GO) nanocomposites as a viable option by revealing their improved electrochemical performance, including enhanced charge storage capacity and prolonged cycling stability. The ZIF-8@GO electrode exhibited an exceptional specific capacitance of 1372.67F/g at 1 A/g, indicating remarkable energy storage capacity. Furthermore, it showed exceptional cycling stability and durability by maintaining 96.02% of its capacitance after 20,000 cycles. To further evaluate ZIF-8@GO for energy storage, an asymmetric supercapacitor was assembled using the engineered electrode and activated carbon as the cathode and anode, respectively. The ZIF-8@GO nanostructure device demonstrated outstanding energy storage capability, maintaining a high specific capacitance of 165.29F/g at 1 A/g. Additionally, the device exhibited remarkable stability and endurance after 20,000 cycles, retaining 87.47% of its initial value. The promising electrochemical performance and ability of ZIF-8@GO nanocomposite to maintain capacitance across multiple cycles suggest a potential for advanced supercapacitor electrode materials.

Tailoring the electrochemical performance of rods-like Co-MOF: Fe-derived Co3O4: Fe electrodes for supercapacitor applications

With the increasing global demand for energy, there is a critical need for efficient and sustainable energy storage solutions. Supercapacitors (SCs) have emerged as promising candidates due to their high-power density, long cycle life, and environmental friendliness. This study explores the development of iron-doped cobalt metal–organic frameworks (Co-MOFs: Fe) and their derived oxides supported on Ni foam as high-performance supercapacitor electrodes. The impact of conversion temperature on electrochemical properties of Co-MOFs: Fe derived Co3O4: Fe was evaluated. The results disclosed that the conversion at 500 °C significantly enhances the surface area, specific capacitance, and charge transfer efficiency of the electrodes. It exhibited the highest specific capacity of ∼ 2135.08 F g−1 at a current density of 1 A/g, along with excellent cycling stability of 87 %. Subsequently, an asymmetric supercapacitor was constructed with the MOF-derived Co3O4: Fe at 500 °C as anode and activated carbon as cathode materials. The device exhibited a specific capacitance of 233.98 F g−1 at 1 A/g with an energy density of ∼ 51.99 Wh/kg, power density of 500.14 W/kg, and a significant capacity retention of ∼ 89 % over 10,000 cycles. These findings validate the potential of Co-MOF: Fe derived Fe-doped Co3O4 as potential materials for practical energy storage applications.

SiC-induced modification of MnCo2O4 nanoneedles fabricated on Ni foam for binder-free electrodes in high-performance asymmetrical supercapacitors

Supercapacitors with large energy densities are required for commercial applications. Herein, the urchin-like and hexagonal MnCo2O4/SiC composite is prepared in situ on Ni foam. The urchin-like MnCo2O4/SiC consists of nanoneedle clusters with a length of about 10 μm and a diameter of 20 nm. The MnCo2O4/SiC||AC asymmetrical supercapacitor (ASCs) shows an energy density of 90.3 Wh/kg (1.73F cm−2) at a power density of 1.25 kW/kg together with 92.1 % retention of the specific capacitance after 10,000 cycles. The results reveal excellent properties and large commercial potential.