Symmetric electric double-layer capacitor containing imidazolium ionic liquid-based solid polymer electrolyte: Effect of TiO2 and ZnO nanoparticles on electrochemical behavior

Poly(vinylidene fluoride-co-hexafluoropropene) (PVDF–HFP)-based polymer electrolytes embedded with 1-ethyl-3-methylimidazolium tetrafluoroborate ioniliquid have been synthesized to improve the ionic conductivity. Electric double-layer capacitors (EDLC) have been prepared using the synthesized polymer electrolytes. Inorganic oxide fillers (5 wt %) such as titanium dioxide (TiO₂) and zinc oxide (ZnO) nanoparticles have been added to polymer electrolytes to compare the electrochemical behavior of the fabricated EDLC. The intrinsic dielectric constant of nanoparticles contributes in ionic dissociation which enhances ionic conductivity of electrolytes and also controls the specific capacitance of the EDLC fabricated with these electrolytes. Physicochemical properties of polymer nanocomposites have been investigated using X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared analysis, which confirms decrease of crystalline phase in host polymer PVDF–HFP. The maximum voltage stability is obtained for TiO₂-based polymer electrolyte. The high specific capacitance as well as high energy density is obtained for the EDLC cell with TiO₂-based polymer electrolyte compared to EDLC with ZnO nanoparticles-based electrolyte. EDLC cells show specific capacitance of 76.4 and 44.51% of initial specific capacitance value at 2000th cycle for ZnO and TiO₂-based polymer electrolytes, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48757.     

Gel Polymer Electrolyte with Anion‐Trapping Boron Moieties via One‐Step Synthesis for Symmetrical Supercapacitors

A novel gel polymer electrolyte (GPE) which is based on new synthesized boron‐containing monomer, benzyl methacrylate, 1 m LiClO₄/N,N‐dimethylformamidel liquid electrolyte solution is prepared through a one‐step synthesis method. The boron‐containing GPE (B‐GPE) not only displays excellent mechanical behavior, favorable thermal stability, but also exhibits an outstanding ionic conductivity of 2.33 mS cm^?1 at room temperature owing to the presence of anion‐trapping boron sites. The lithium ion transference in this gel polymer film at ambient temperature is 0.60. Furthermore, the symmetrical supercapacitor which is fabricated with B‐GPE as electrolyte and reduced graphene oxide as electrode demonstrates a broad potential window of 2.3 V. The specific capacitance of symmetrical B‐GPE supercapacitors retains 90% after 3000 charge–discharge cycles at current density of 1 A g^?1.     

A redox‐mediator‐doped gel polymer electrolyte applied in quasi‐solid‐state supercapacitors

Methylene blue (MB) redox mediator was introduced into polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) blend host to prepare a gel polymer electrolyte (PVA‐PVP‐H₂SO₄‐MB) for a quasi‐solid‐state supercapacitor. The electrochemical properties of the supercapacitor with the prepared gel polymer electrolyte were evaluated by cyclic voltammetry, galvanostatic charge–discharge, electrochemical impedance spectroscopy, and self‐discharge measurements. With the addition of MB mediator, the ionic conductivity of gel polymer electrolyte increased by 56% up to 36.3 mS·cm^?1, and the series resistance reduced, because of the more efficient ionic conduction and higher charge transfer rate, respectively. The electrode specific capacitance of the supercapacitor with PVA‐PVP‐H₂SO₄‐MB electrolyte is 328 F·g^?1, increasing by 164% compared to that of MB‐undoped system at the same current density of 1 A·g^?1. Meanwhile, the energy density of the supercapacitor increases from 3.2 to 10.3 Wh·kg^?1. The quasi‐solid‐state supercapacitor showed excellent cyclability over 2000 charge/discharge cycles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39784.     

LiClO4 doped cellulose acetate as biodegradable polymer electrolyte for supercapacitors

The possibility of producing a biodegradable polymer electrolyte based on cellulose acetate (CA) with varied concentration of LiClO₄ for use in supercapacitors has been investigated. The successful doping of the CA films has been analyzed by FTIR and DSC measurements of the LiClO₄ doped CA films. The ionic conductivity of the films increased with increase in salt content and the maximum ionic conductivity obtained for the solid polymer electrolyte at room temperature was 4.9 × 10^?3 Ω^?1 for CA with 16% LiClO₄. The biodegradation of the solid polymer electrolyte films have been tested by soil burial, degradation in activated sludge, and degradation in buffer medium methods. The extent of biodegradation in the films has been measured by AC Impedance spectroscopy and weight loss calculations. The study indicated sufficient biodegradability of the materials. A p/p polypyrrole supercapacitor has been fabricated and its electrochemical characteristics and performance have been studied. The supercapacitor showed a fairly good specific capacitance of 90 F g^?1 and a time constant of 1 s. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

有机添加剂对超级电容器中水系电解液理化性能的影响

以6 mol/L KOH水溶液为电解液,高比表面积的活性炭为活性物质,研究了有机添加剂对体系润湿性、电导率、工作电压窗口及阻抗的影响,测试了超级电容器的电化学性能。结果表明,适量添加有机添加剂可明显抑制体系的极化现象,提高超级电容器的工作电压窗口。添加10vol%异丙醇时,电极材料和电解液间的润湿性大幅提高,比电容从79.3 F/g提高至113.2 F/g。添加20vol%异丙醇时,超级电容器的能量密度达19.4 Wh/kg,体系的电荷转移电阻明显降低,在10 A/g电流密度下的比电容比0.5 A/g时下降13.9%,而不加添加剂时下降30.3%。添加30vol%异丙醇时,电解液电导率迅速下降,比电容降低,电导率是影响比电容的关键因素。     

Janus POSS-based hydrogel electrolytes with highly stretchable and low-temperature resistant performances for all-in-one supercapacitors

Conductive hydrogels can be utilized in the field of flexible supercapacitors due to their stretchable properties and high ionic conductivity. However, many of the conductive hydrogels lose their stretchability and conductivity at subzero temperatures. Herein, a novel Janus POSS-based hydrogel electrolyte that shows excellent flexibility and ionic conductivity at low temperatures is designed and prepared by the copolymerization of acrylamide and a water-soluble Janus-type polyhedral oligomeric silsesquioxane (AS-POSS) containing sodium sulfonate groups and double bonding groups. The sodium sulfonate groups of AS-POSS and LiCl endow the hydrogel electrolyte with excellent anti-freezing ability. Simultaneously, the double bonding groups of AS-POSS enable a successful POSS crosslinking in the polymer network, resulting in a highly stretchable hydrogel electrolyte (1445%) with high ionic conductivity (0.067 S cm⁻¹) at −20°C. Thereafter, the all-in-one flexible supercapacitor is prepared by in-situ polymerization of aniline. Based on the exceptional anti-freezing properties of the Janus POSS-based hydrogel electrolyte, the all-in-one supercapacitor exhibits stable electrochemical performance (>90% capacitance retained under deformation at −20°C) and excellent cycling stability (only 19.7% capacitance decay over 2000 charge/discharge cycles at −20°C) at low temperatures. The Janus POSS-based hydrogel electrolyte is expected to be a promising gel electrolyte for an all-in-one supercapacitor that resists freezing.     

Improved performance of carbon‐based supercapacitors with sulfonated poly(ether ether ketone)/poly(vinyl alcohol) composite membranes as separators

Supercapacitors have attracted much interest because of their high power density and long cycling life. However, the porous polypropylene membranes that are widely used as separators in supercapacitors are unfavorable for transporting ions and constructing the interfaces between electrolyte and electrodes due to their hydrophobic property. As a consequence, a crosslinked solid polymer electrolyte membrane and a semi‐interpenetrating polymer network (sIPN) were fabricated from sulfonated poly(ether ether ketone) (SPEEK) and poly(vinyl alcohol) (PVA), which can be used as hydrophilic separators. Their structures were examined using Fourier transform infrared spectroscopy. The electrochemical properties of assembled electrical double‐layer capacitors (EDLCs) were investigated using cyclic voltammetry, galvanostatic charging–discharging and impedance analysis. At a current density of 1 A g^?1, a single electrode in the EDLC with the sIPN shows a specific capacitance of 134 F g^?1. As a comparison, a single electrode in the EDLC with a SPEEK membrane demonstrates a specific capacitance of only 121 F g^?1. After 1000 charge–discharge cycles, the specific capacitance retentions of both EDLCs are nearly 100%. These results suggest that the sIPN based on SPEEK and PVA has great potential to serve as a separator in EDLCs. © 2018 Society of Chemical Industry     

硅酸盐水泥基复合电解质的制备及其在建筑储能器件中的应用

近几年,将水泥基复合材料用于建筑储能已成为研究热点之一。本文将硅酸盐水泥、丙烯酰胺(AM)混合制备了一种优化的水泥基复合结构电解质,并研究了AM质量分数分别为0%、25.0%、27.5%、30.0%、32.5%和35.0%时对结构电解质的离子电导率、力学性能及微观结构的影响。研究结果表明,增加AM的掺量有助于提高硅酸盐水泥基复合电解质的离子电导率,同时会不可避免地降低电解质的抗压强度。当AM掺量为30.0%时,可以使离子电导率和抗压强度达到理想平衡,抗压强度高达41.1 MPa,离子电导率最大为22.47 mS·cm^-1。此外,对结构电解质与还原氧化石墨烯(rGO)电极组装成一体式的结构超级电容器进行了一系列电化学性能测试,发现AM掺量为30.0%的硅酸盐水泥基复合电解质构成的结构超级电容器的面积比电容最大可以达到96.8 mF·cm^-2。在恒定电流为0.1 mA·cm^-2下充放电循环5 000次后,该结构超级电容器的面积比电容值保持率为91.08%,该结构超级电容器在建筑储能领域具有广阔的应用前景。     

Synthesis and characterization of novel crosslinked polyurethane–acrylate electrolyte

Flexible, transparent, and crosslinked polymer films were synthesized by polymerization of PEG‐modified urethane acrylate using a simple method. A series of novel solid polymer electrolytes and gel electrolytes were prepared based on this type of polymer film. To understand the interactions among salt, solvent, and polymer, the swelling behaviors of the crosslinked polymer in pure propylene carbonate (PC) and liquid electrolyte solutions (LiClO₄/PC) were investigated. The results showed that the swelling rate in the electrolyte solution containing moderate LiClO₄ was greater than that in pure PC. Thermogravimetric analysis (TGA) also supported the interaction between the solvent and polymer. The morphology and crystallinity of the crosslinked polymer and polymer electrolytes were studied using atomic force microscopy (AFM) and wide‐angle X‐ray diffraction (WAXD) spectroscopy. The effects of the content of the electrolyte solution on the ionic conductivity of gel electrolytes were explored. The dependence of the conductivity on the amount of the electrolyte solution was nonlinear. With a different content of the plasticizer, the ionic conduction pathway of the polymer electrolytes would be changed. The best ionic conductivity of the gel electrolytes, which should have good mechanical properties, was 4 × 10^r?3 S cm^?1 at 25°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 340–348, 2003     

1-Methyl-3-butylimidazolium tetraflouroborate with activated carbon for electrochemical double layer supercapacitors

This article presents the main features of electrochemical double layer supercapacitors, made of nanostructured carbon materials with specially selected and optimized porosity structure and electrolyte based on solvent-free ionic liquid as follows 1-methyl-3-butylimidazolium tetrafluoroborate (1Me3BuImBF₄). The performance of supercapacitor was carried out by cyclic voltammetry and galvanostatic charge/discharge measurements. The main characteristics of stacked supercapacitors exhibit a nominal voltage 3.0 V and a maximum cell voltage 3.5 V as well as a specific capacitance (individual electrode of supercapacitor) of 111 F/g. The specific energy of 4.1 Wh/kg and specific power of 1.7 W/kg for industrial stacked supercapacitor has been achieved.     

Preparation and characterization of gel polymer electrolyte based on PVA-K2CO3

ABSTRACT

In this study, electrolyte materials were synthesized by mixing a highly conducting salt (K₂CO₃) with the poly(vinyl alcohol) (PVA) in different proportions (from 10 to 50 wt.%). The synthesized electrolyte was characterized using Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV) for their functional groups, morphology, thermal stability, glass transition temperature (T_g ), ionic conductivity, and potential window, respectively. Characterization results show that the complex formation between PVA and K₂CO₃ salt has been established by FTIR spectroscopic study, which indicates the detailed interaction between PVA and the salts in PVA-K₂CO₃ composites while the amorphous nature of the electrolyte after incorporation of the salts has been confirmed by FESEM analysis. Similarly, TGA and DSC analysis revealed that both decomposition temperature and T_g of the synthesized electrolytes decrease with the addition of K₂CO₃ due to the strong plasticizing effect of the salt. The results confirm that the electrolytes have sufficient thermal stability for supercapacitor operation, as well as an amorphous phase to effectively deliver high ionic conductivity. The highest ionic conductivity of 4.53 × 10^?3 S cm^?1 at 373 K and potential window of 2.7 V was exhibited by PK30 (30 wt.% K₂CO₃), which can be considered as high value for solid-state electrolytes which are superior to those electrolytes from PVA salts earlier reported. The results similarly show that the prepared electrolyte is temperature-dependent as conductivity increase with increase in temperature. Based on these properties, it can be imply that the PVA-K₂CO₃ gel polymer electrolyte (GPE) could be a promising electrolyte candidate for EDLC applications. The results indicate that the PVA-K₂CO₃ as a new electrolyte material has great potential in practical applications of portable energy-storage devices.     

Ni(OH)2与不同碳质材料复合制备超级电容器电极材料研究进展

超级电容器具有功率密度大、寿命长、生产成本低等优点,被认为是最有发展前途的储能系统之一。然而,超级电容器的低能量密度阻碍了其实际应用。由于存储的能量与CV2成正比,可以通过增加材料的电容"C"或操作电压窗口"V"或两者同时增加来提高超级电容器的能量密度。然而具有宽电位窗口的有机电解质离子往往电导率差,成本高,容易引起环境问题。因此为改善能量密度,应采用高比电容的电极材料,故而设计出具有高比电容的适合电极材料就成为研究热点。Ni(OH)2作为超级电容器电极材料,具有理论容量大、成本低、天然丰富、易于合成等优点,近年来备受关注。但由于Ni(OH)2导电率低、比表面积小,其容量劣化严重。碳质材料作为双电层超级电容器的电极材料,其能量存储机制取决于电极表面的电解质离子吸附和解离,具有导电率好、原料丰富、成本较低、电化学稳定性高等优点而应用广泛。因此,有必要将高导电碳质材料引入Ni(OH)2组成复合材料以提高电容性能。笔者综述了Ni(OH)2基材料的合成方法,特别是与碳质材料复合来提高Ni(OH)2基材料的循环稳定性和倍率性能方面的研究新进展。     

Fabrication and properties of crosslinked poly(propylene carbonate maleate) gel polymer electrolyte for lithium‐ion battery

The poly(propylene carbonate maleate) (PPCMA) was synthesized by the terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride. The PPCMA polymer can be readily crosslinked using dicumyl peroxide (DCP) as crosslinking agent and then actived by absorbing liquid electrolyte to fabricate a novel PPCMA gel polymer electrolyte for lithium‐ion battery. The thermal performance, electrolyte uptake, swelling ratio, ionic conductivity, and lithium ion transference number of the crosslinked PPCMA were then investigated. The results show that the T_g and the thermal stability increase, but the absorbing and swelling rates decrease with increasing DCP amount. The ionic conductivity of the PPCMA gel polymer electrolyte firstly increases and then decreases with increasing DCP ratio. The ionic conductivity of the PPCMA gel polymer electrolyte with 1.2 wt % of DCP reaches the maximum value of 8.43 × 10⁻³ S cm⁻¹ at room temperature and 1.42 × 10⁻² S cm⁻¹ at 50°C. The lithium ion transference number of PPCMA gel polymer electrolyte is 0.42. The charge/discharge tests of the Li/PPCMA GPE/LiNi_1/3Co_1/3Mn_1/3O₂ cell were evaluated at a current rate of 0.1C and in voltage range of 2.8–4.2 V at room temperature. The results show that the initial discharge capacity of Li/PPCMA GPE/LiNi_1/3Co_1/3Mn_1/3 O₂ cell is 115.3 mAh g⁻¹. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Nano-size LiAlO2 ceramic filler incorporated porous PVDF-co-HFP electrolyte for lithium-ion battery applications

The optimized composition of PVdF-co-HFP-LiAlO₂ based micro-porous nano-composite polymer electrolyte membranes (MPNCPEMs) was prepared with a preferential polymer dissolution process. Nitrogen adsorption isotherms and SEM micrographs showed that the enhanced ionic conductivity of polymer electrolyte was due to increase in pore-size, surface area and pore density, results an increase in the electrolyte uptake. The ac-impedance spectroscopy showed that the room temperature ionic conductivity of PVdF-co-HFP-LiAlO₂ based polymer electrolyte membranes increased with the removal of PVA content and attained the maximum ionic conductivity of 8.12 × 10⁻³ S cm⁻¹. The prepared MPNCPEM of high ionic conductivity was subjected into LSV study. Finally, the electrode/electrolyte interfacial resistance was evaluated by monitoring the impedance response at different time intervals.     

PEDOT solid-state polymer supercapacitor assembled with a KI-doped gel polymer electrolyte

Solid-state polymer supercapacitors (SSP-SCs) have vast potential for future development due to their compact, safe, environment-friendly, and facile designing. Thus, prevalent researches have been explored in this area. In this article, poly(3,4-ethylenedioxythiophene) (PEDOT) SSP-SCs were assembled by using poly(3,4-ethylenedioxythiophene)/carbon paper (PEDOT/CP) as electrodes and polyvinyl alcohol/sulfuric acid/potassium iodide (PVA/H₂SO₄/KI) as the gel polymer electrolyte. The effect of KI content on the electrochemical performance of the SC was studied by cyclic voltammetry, galvanostatic charge–discharge measurements (GCD), and electrochemical impedance spectroscopy. The results indicated that the PEDOT SSP-SC has excellent electrochemical properties when KI doping amount was 60 wt %. The introduction of KI increased the specific capacitance due to the improved ionic conductivity and additional pseudocapacitance reaction at the electrode–electrolyte interface. The PEDOT SSP-SC showed high energy and power densities of 451.32 Wh kg⁻¹ and 13.29 kW kg⁻¹, respectively, as well as a specific capacitance of 352.59 F g⁻¹ for a discharge current of 1 mA cm⁻². In addition, after 1000 GCD cycles, the PVA/H₂SO₄/KI-based PEDOT SSP-SC showed capacitance retention of 74.08%. Therefore, the SC exhibits outstanding energy and power density and good cycle stability and has great potential to be used in high-energy density equipment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48723.     

Electrochemical properties of novel ionic liquids for electric double layer capacitor applications

An aliphatic quaternary ammonium salt which has a methoxyethyl group on the nitrogen atom formed an ionic liquid (room temperature molten salt) when combined with the tetrafluoroborate (BF₄⁻) and bis(trifluoromethylsulfonyl)imide [TFSI; (CF₃SO₂)₂N⁻] anions. The limiting oxidation and reduction potentials, specific conductivity, and some other physicochemical properties of the novel ionic liquids, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium tetrafluoroborate (DEME-BF₄) and DEME-TFSI have been evaluated and compared with those of 1-ethyl-3-methylimidazolium tetrafluoroborate. DEME-BF₄ is a practically useful ionic liquid for electrochemical capacitors as it has a quite wide potential window (6.0 V) and high ionic conductivity (4.8 mS cm⁻¹ at 25 °C). We prepared an electric double layer capacitor (EDLC) composed of a pair of activated carbon electrodes and DEME-BF₄ as the electrolyte. This EDLC (working voltage ∼2.5 V) has both, a higher capacity above room temperature and a better charge-discharge cycle durability at 100 °C when compared to a conventional EDLC using an organic liquid electrolyte such as a tetraethylammonium tetrafluoroborate in propylene carbonate.     

Perovskite oxide and polyazulene–based heterostructure for high–performance supercapacitors

Several types of electrode materials have been developed for high–performance supercapacitors. Most of the relevant studies have focused on the discovery of new atomic structures and paid limited attention to the effect of heterostructures in supercapacitor electrodes, which has long hindered the fundamental understanding of the use of hybrid materials in supercapacitors. In this study, a novel heterostructure based on perovskite oxide (LaNiO₃) nanosheets and polyazulene was synthesized. The as–prepared heterostructure–based supercapacitor exhibited a specific capacitance of up to 464 F g⁻¹ at a high current density of 2 A g⁻¹ in 1–ethyl–3–methylimidazolium tetrafluoroborate. In a symmetric supercapacitor, this heterostructure delivered an energy density of up to 56.4 Wh kg⁻¹ at a power density of 1100 W kg⁻¹. Both LaNiO₃ and polyazulene contributed pseudocapacitance and dominated the performance. Unexpectedly, electric double–layer capacitance was found to contribute in this system. Density functional theory calculations indicated that the advantage of the high electrical conductivity of the heterostructure benefited the supercapacitor operation. Electrochemical quartz crystal microbalance analysis revealed that the fast ion flux and adsorption boosted performance. The high intrinsic electrical conductivity and improved stability make this heterostructure a promising electrode material candidate for supercapacitors.     

Electrochemical properties of MnO2/CNT nanocomposite in neutral aqueous electrolyte as cathode material for asymmetric supercapacitors

A MnO₂/carbon nanotube (CNT) nanocomposite was synthesised using a simple hydrothermal treatment. The nanocomposite exhibits a CNT core/MnO₂ porous sheath hierarchy architecture, which makes it promising as an electrode material for supercapacitors. An asymmetric supercapacitor based on activated carbon (AC) as anode, MnO₂/CNT nanocomposite as cathode and 1M Na₂SO₄ solution as electrolyte was assembled in a Swagelok cell. The full cell exhibits excellent power capability, cycling stability and a high energy density of 23 W h/kg at a power density of 330 W/kg based on the total mass of the active electrode materials. This AC//MnO₂/CNT asymmetric supercapacitor is promising for high-power applications due to its high energy density and power density.     

Diamond-coated silicon wires for supercapacitor applications in ionic liquids

For a long time sp² carbon has been the dominating material for supercapacitor applications. In this paper a new concept of using boron-doped diamond for supercapacitors is proposed. Diamond surface enlargement is realized via bottom-up template-growth. In this method, silicon nanowire electrodes are coated with a thin (~ 100 nm) layer of nanocrystalline diamond (NCD) by microwave enhanced chemical vapor deposition (MWCVD). The quality of overgrowth is characterized by high resolution scanning electron microscopy which reveals a homogeneous coverage of diamond on Si nanowire surface. To enhance the potential window to 4 V, a room temperature ionic liquid is used as electrolyte. The dilution of the ionic liquid is investigated in terms of conductivity and specific capacitance. The capacitance as measured via cyclic voltammetry reaches 105 μF/cm². An energy density of 84 μJ/cm² and a high power density of 0.94 mW/cm² are obtained in combination with good stability of over 10,000 charging/discharging cycles.     

Fabrication and characterization of PEO/PPC polymer electrolyte for lithium‐ion battery

A new poly(propylene carbonate)/poly(ethylene oxide) (PEO/PPC) polymer electrolytes (PEs) have been developed by solution‐casting technique using biodegradable PPC and PEO. The morphology, structure, and thermal properties of the PEO/PPC polymer electrolytes were investigated by scanning electron microscopy, X‐ray diffraction, and differential scanning calorimetry methods. The ionic conductivity and the electrochemical stability window of the PEO/PPC polymer electrolytes were also measured. The results showed that the T_g and the crystallinity of PEO decrease, and consequently, the ionic conductivity increases because of the addition of amorphous PPC. The PEO/50%PPC/10%LiClO₄ polymer electrolyte possesses good properties such as 6.83 × 10^?5 S cm^?1 of ionic conductivity at room temperature and 4.5 V of the electrochemical stability window. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010