Pseudocapacitance

Last updated
Simplified view of a double-layer with specifically adsorbed ions which have submitted their charge to the electrode to explain the faradaic charge-transfer of the pseudocapacitance. Pseudocapacitance-Priciple.png
Simplified view of a double-layer with specifically adsorbed ions which have submitted their charge to the electrode to explain the faradaic charge-transfer of the pseudocapacitance.
Hierarchical classification of supercapacitors and related types Supercapacitors-Short-Overview.png
Hierarchical classification of supercapacitors and related types

Pseudocapacitance is the electrochemical storage of electricity in an electrochemical capacitor that occurs due to faradaic charge transfer originating from a very fast sequence of reversible faradaic redox, electrosorption or intercalation processes on the surface of suitable electrodes. [1] [2] [3] Pseudocapacitance is accompanied by an electron charge-transfer between electrolyte and electrode coming from a de-solvated and adsorbed ion. One electron per charge unit is involved. The adsorbed ion has no chemical reaction with the atoms of the electrode (no chemical bonds arise [4] ) since only a charge-transfer takes place. Supercapacitors that rely primarily on pseudocapacitance are sometimes called pseudocapacitors. [5] [6] [7]

Contents

Faradaic pseudocapacitance only occurs together with static double-layer capacitance. Pseudocapacitance and double-layer capacitance both contribute inseparably to the total capacitance value. The amount of pseudocapacitance depends on the surface area, material and structure of the electrodes. Pseudocapacitance may contribute more capacitance than double-layer capacitance for the same surface area by 100x. [1]

The amount of electric charge stored in a pseudocapacitance is linearly proportional to the applied voltage. The unit of pseudocapacitance is farad.

History

Redox reactions

Differences

Rechargeable batteries

Redox reactions in batteries with faradaic charge-transfer between an electrolyte and the surface of an electrode were characterized decades ago. These chemical processes are associated with chemical reactions of the electrode materials usually with attendant phase changes. Although these chemical processes are relatively reversible, battery charge/discharge cycles often irreversibly produce unreversed chemical reaction products of the reagents. Accordingly, the cycle-life of rechargeable batteries is usually limited. Further, the reaction products lower power density. Additionally, the chemical processes are relatively slow, extending charge/discharge times.

Electro-chemical capacitors

Schematic representation of a double layer on an electrode (BMD) model. 1. Inner Helmholtz plane, (IHP), 2. Outer Helmholtz plane (OHP), 3. Diffuse layer, 4. Solvated electrolyte ions (cations) 5. Specifically adsorbed ions (redox ion, which contributes to the pseudocapacitance), 6. Molecules of the solvent Electric double-layer (BMD model) NT-int.svg
Schematic representation of a double layer on an electrode (BMD) model. 1. Inner Helmholtz plane, (IHP), 2. Outer Helmholtz plane (OHP), 3. Diffuse layer, 4. Solvated electrolyte ions (cations) 5. Specifically adsorbed ions (redox ion, which contributes to the pseudocapacitance), 6. Molecules of the solvent

A fundamental difference between redox reactions in batteries and in electrochemical capacitors (supercapacitors) is that in the latter, the reactions are a very fast sequence of reversible processes with electron transfer without any phase changes of the electrode molecules. They do not involve making or breaking chemical bonds. The de-solvated atoms or ions contributing the pseudocapacitance simply cling [4] to the atomic structure of the electrode and charges are distributed on surfaces by physical adsorption processes. Compared with batteries, supercapacitor faradaic processes are much faster and more stable over time, because they leave only traces of reaction products. Despite the reduced amount of these products, they cause capacitance degradation. This behavior is the essence of pseudocapacitance.

Pseudocapacitive processes lead to a charge-dependent, linear capacitive behavior, as well as the accomplishment of non-faradaic double-layer capacitance in contrast to batteries, which have a nearly charge-independent behavior. The amount of pseudocapacitance depends on the surface area, material and structure of the electrodes. The pseudocapacitance may exceed the value of double-layer capacitance for the same surface area by 100x. [1]

Capacitance functionality

Intercalated metal atoms between planar graphite layers Intercalactionrp.svg
Intercalated metal atoms between planar graphite layers
Confinement of solvated ions in pores, such as those present in carbide-derived carbon (CDC). As the pore size approaches the size of the solvation shell, the solvent molecules are removed, resulting in larger ionic packing density and increased charge storage capability. Figure5CDC.jpg
Confinement of solvated ions in pores, such as those present in carbide-derived carbon (CDC). As the pore size approaches the size of the solvation shell, the solvent molecules are removed, resulting in larger ionic packing density and increased charge storage capability.

Applying a voltage at the capacitor terminals moves the polarized ions or charged atoms in the electrolyte to the opposite polarized electrode. Between the surfaces of the electrodes and the adjacent electrolyte an electric double-layer forms. One layer of ions on the electrode surface and the second layer of adjacent polarized and solvated ions in the electrolyte move to the opposite polarized electrode. The two ion layers are separated by a single layer of electrolyte molecules. Between the two layers, a static electric field forms that results in double-layer capacitance. Accompanied by the electric double-layer, some de-solvated electrolyte ions pervade the separating solvent layer and are adsorbed by the electrode's surface atoms. They are specifically adsorbed and deliver their charge to the electrode. In other words, the ions in the electrolyte within the Helmholtz double-layer also act as electron donors and transfer electrons to the electrode atoms, resulting in a faradaic current. This faradaic charge transfer, originated by a fast sequence of reversible redox reactions, electrosorptions or intercalation processes between electrolyte and the electrode surface is called pseudocapacitance. [8]

Depending on the electrode's structure or surface material, pseudocapacitance can originate when specifically adsorbed ions pervade the double-layer, proceeding in several one-electron stages. The electrons involved in the faradaic processes are transferred to or from the electrode's valence-electron states (orbitals) and flow through the external circuit to the opposite electrode where a second double-layer with an equal number of opposite-charged ions forms. The electrons remain in the strongly ionized and electrode surface's "electron hungry" transition-metal ions and are not transferred to the adsorbed ions. This kind of pseudocapacitance has a linear function within narrow limits and is determined by the potential-dependent degree of surface coverage of the adsorbed anions. The storage capacity of the pseudocapacitance is limited by the finite quantity of reagent or of available surface.

Systems that give rise to pseudocapacitance: [8]

All three types of electrochemical processes have appeared in supercapacitors. [8] [9]

When discharging pseudocapacitance, the charge transfer is reversed and the ions or atoms leave the double-layer and spread throughout the electrolyte.

Materials

Electrodes' ability to produce pseudocapacitance strongly depends on the electrode materials' chemical affinity to the ions adsorbed on the electrode surface as well as on the electrode pore structure and dimension. Materials exhibiting redox behavior for use as pseudocapacitor electrodes are transition-metal oxides inserted by doping in the conductive electrode material such as active carbon, as well as conducting polymers such as polyaniline or derivatives of polythiophene covering the electrode material.

Transition metal oxides/sulfides

These materials provide high pseudocapacitance and were thoroughly studied by Conway. [1] [10] Many oxides of transition metals like ruthenium (RuO
2), iridium (IrO
2), iron (Fe
3O
4), manganese (MnO
2) or sulfides such as titanium sulfide (TiS
2) or their combinations generate faradaic electron–transferring reactions with low conducting resistance.[ citation needed ]

Ruthenium dioxide (RuO
2) in combination with sulfuric acid (H
2SO
4) electrolyte provides one of the best examples of pseudocapacitance, with a charge/discharge over a window of about 1.2 V per electrode. Furthermore, the reversibility on these transition metal electrodes is excellent, with a cycle life of more than several hundred-thousand cycles. Pseudocapacitance originates from a coupled, reversible redox reaction with several oxidation steps with overlapping potential. The electrons mostly come from the electrode's valence orbitals. The electron transfer reaction is very fast and can be accompanied with high currents.

The electron transfer reaction takes place according to:

where [11]

During charge and discharge, H+
 (protons) are incorporated into or removed from the RuO
2 crystal lattice, which generates storage of electrical energy without chemical transformation. The OH groups are deposited as a molecular layer on the electrode surface and remain in the region of the Helmholtz layer. Since the measurable voltage from the redox reaction is proportional to the charged state, the reaction behaves like a capacitor rather than a battery, whose voltage is largely independent of the state of charge.

Conducting polymers

Another type of material with a high amount of pseudocapacitance is electron-conducting polymers. Conductive polymer such as polyaniline, polythiophene, polypyrrole and polyacetylene have a lower reversibility of the redox processes involving faradaic charge transfer than transition metal oxides, and suffer from a limited stability during cycling.[ citation needed ] Such electrodes employ electrochemical doping or dedoping of the polymers with anions and cations. Highest capacitance and power density are achieved with a n/p-type polymer configuration, with one negatively charged (n-doped) and one positively charged (p-doped) electrode.

Structure

Pseudocapacitance may originate from the electrode structure, especially from the material pore size. The use of carbide-derived carbons (CDCs) or carbon nanotubes (CNTs) as electrodes provides a network of small pores formed by nanotube entanglement. These nanoporous materials have diameters in the range of <2 nm that can be referred to as intercalated pores. Solvated ions in the electrolyte are unable to enter these small pores, but de-solvated ions that have reduced their ion dimensions are able to enter, resulting in larger ionic packing density and increased charge storage. The tailored sizes of pores in nano-structured carbon electrodes can maximize ion confinement, increasing specific capacitance by faradaic H
2 adsorption treatment. Occupation of these pores by de-solvated ions from the electrolyte solution occurs according to (faradaic) intercalation. [12] [13] [14]

Verification

A cyclic voltammogram shows the fundamental difference of the current curves between static capacitors and pseudocapacitors Voltagram-Engl.png
A cyclic voltammogram shows the fundamental difference of the current curves between static capacitors and pseudocapacitors

Pseudocapacitance properties can be expressed in a cyclic voltammogram. For an ideal double-layer capacitor, the current flow is reversed immediately upon reversing the potential yielding a rectangular-shaped voltammogram, with a current independent of the electrode potential. For double-layer capacitors with resistive losses, the shape changes to a parallelogram. In faradaic electrodes the electrical charge stored in the capacitor is strongly dependent on the potential, therefore, the voltammetry characteristics deviate from the parallelogram due to a delay while reversing the potential, ultimately coming from kinetic charging processes. [15] [16]

Examples

Brezesinki et al. showed that mesoporous films of α-MoO3 have improved charge storage due to lithium ions inserting into the gaps of α-MoO3. They claim this intercalation pseudocapacitance takes place on the same timescale as redox pseudocapacitance and gives better charge-storage capacity without changing kinetics in mesoporous MoO3. This approach is promising for batteries with rapid charging ability, comparable to that of lithium batteries, [17] and is promising for efficient energy materials.

Other groups have used vanadium oxide thin films on carbon nanotubes for pseudocapacitors. Kim et al. electrochemically deposited amorphous V2O5·xH2O onto a carbon nanotube film. The three-dimensional structure of the carbon nanotubes substrate facilitates high specific lithium-ion capacitance and shows three times higher capacitance than vanadium oxide deposited on a typical Pt substrate. [18] These studies demonstrate the capability of deposited oxides to effectively store charge in pseudocapacitors.

Conducting polymers, such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT), have tunable electronic conductivity and can achieve high doping levels with the proper counterion. A high-performing conducting polymer pseudocapacitor has high cycling stability after undergoing charge/discharge cycles. Successful approaches include embedding the redox polymer in a host phase (e.g. titanium carbide) for stability and depositing a carbonaceous shell onto the conducting polymer electrode. These techniques improve cyclability and stability of the pseudocapacitor device. [19]

Applications

Pseudocapacitance is an important property in supercapacitors.

Related Research Articles

<span class="mw-page-title-main">Capacitor types</span> Manufacturing styles of an electronic device

Capacitors are manufactured in many styles, forms, dimensions, and from a large variety of materials. They all contain at least two electrical conductors, called plates, separated by an insulating layer (dielectric). Capacitors are widely used as parts of electrical circuits in many common electrical devices.

<span class="mw-page-title-main">Flow battery</span> Type of electrochemical cell

A flow battery, or redox flow battery, is a type of electrochemical cell where chemical energy is provided by two chemical components dissolved in liquids that are pumped through the system on separate sides of a membrane. Ion transfer inside the cell occurs across the membrane while the liquids circulate in their respective spaces.

<span class="mw-page-title-main">Nanobatteries</span> Type of battery

Nanobatteries are fabricated batteries employing technology at the nanoscale, particles that measure less than 100 nanometers or 10−7 meters. These batteries may be nano in size or may use nanotechnology in a macro scale battery. Nanoscale batteries can be combined to function as a macrobattery such as within a nanopore battery.

A paper battery is engineered to use a spacer formed largely of cellulose. It incorporates nanoscopic scale structures to act as high surface-area electrodes to improve conductivity.

<span class="mw-page-title-main">Double layer (surface science)</span> Molecular interface between a surface and a fluid

In surface science, a double layer is a structure that appears on the surface of an object when it is exposed to a fluid. The object might be a solid particle, a gas bubble, a liquid droplet, or a porous body. The DL refers to two parallel layers of charge surrounding the object. The first layer, the surface charge, consists of ions which are adsorbed onto the object due to chemical interactions. The second layer is composed of ions attracted to the surface charge via the Coulomb force, electrically screening the first layer. This second layer is loosely associated with the object. It is made of free ions that move in the fluid under the influence of electric attraction and thermal motion rather than being firmly anchored. It is thus called the "diffuse layer".

<span class="mw-page-title-main">Lithium-ion capacitor</span> Hybrid type of capacitor

A lithium-ion capacitor is a hybrid type of capacitor classified as a type of supercapacitor. It is called a hybrid because the anode is the same as those used in lithium-ion batteries and the cathode is the same as those used in supercapacitors. Activated carbon is typically used as the cathode. The anode of the LIC consists of carbon material which is often pre-doped with lithium ions. This pre-doping process lowers the potential of the anode and allows a relatively high output voltage compared to other supercapacitors.

Nanoarchitectures for lithium-ion batteries are attempts to employ nanotechnology to improve the design of lithium-ion batteries. Research in lithium-ion batteries focuses on improving energy density, power density, safety, durability and cost.

The lithium–air battery (Li–air) is a metal–air electrochemical cell or battery chemistry that uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow.

Carbide-derived carbon (CDC), also known as tunable nanoporous carbon, is the common term for carbon materials derived from carbide precursors, such as binary (e.g. SiC, TiC), or ternary carbides, also known as MAX phases (e.g., Ti2AlC, Ti3SiC2). CDCs have also been derived from polymer-derived ceramics such as Si-O-C or Ti-C, and carbonitrides, such as Si-N-C. CDCs can occur in various structures, ranging from amorphous to crystalline carbon, from sp2- to sp3-bonded, and from highly porous to fully dense. Among others, the following carbon structures have been derived from carbide precursors: micro- and mesoporous carbon, amorphous carbon, carbon nanotubes, onion-like carbon, nanocrystalline diamond, graphene, and graphite. Among carbon materials, microporous CDCs exhibit some of the highest reported specific surface areas (up to more than 3000 m2/g). By varying the type of the precursor and the CDC synthesis conditions, microporous and mesoporous structures with controllable average pore size and pore size distributions can be produced. Depending on the precursor and the synthesis conditions, the average pore size control can be applied at sub-Angstrom accuracy. This ability to precisely tune the size and shapes of pores makes CDCs attractive for selective sorption and storage of liquids and gases (e.g., hydrogen, methane, CO2) and the high electric conductivity and electrochemical stability allows these structures to be effectively implemented in electrical energy storage and capacitive water desalinization.

<span class="mw-page-title-main">Supercapacitor</span> High-capacity electrochemical capacitor

A supercapacitor (SC), also called an ultracapacitor, is a high-capacity capacitor, with a capacitance value much higher than solid-state capacitors but with lower voltage limits. It bridges the gap between electrolytic capacitors and rechargeable batteries. It typically stores 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerates many more charge and discharge cycles than rechargeable batteries.

Aluminium-ion batteries are a class of rechargeable battery in which aluminium ions serve as charge carriers. Aluminium can exchange three electrons per ion. This means that insertion of one Al3+ is equivalent to three Li+ ions. Thus, since the ionic radii of Al3+ (0.54 Å) and Li+ (0.76 Å) are similar, significantly higher numbers of electrons and Al3+ ions can be accepted by cathodes with little damage. Al has 50 times (23.5 megawatt-hours m-3) the energy density of Li and is even higher than coal.

Double-layer capacitance is the important characteristic of the electrical double layer which appears at the interface between a surface and a fluid. At this boundary two layers of electric charge with opposing polarity form, one at the surface of the electrode, and one in the electrolyte. These two layers, electrons on the electrode and ions in the electrolyte, are typically separated by a single layer of solvent molecules that adhere to the surface of the electrode and act like a dielectric in a conventional capacitor. The amount of charge stored in double-layer capacitor depends on the applied voltage.

Research in lithium-ion batteries has produced many proposed refinements of lithium-ion batteries. Areas of research interest have focused on improving energy density, safety, rate capability, cycle durability, flexibility, and reducing cost.

In materials science, MXenes are a class of two-dimensional inorganic compounds along with MBenes, that consist of atomically thin layers of transition metal carbides, nitrides, or carbonitrides. MXenes accept a variety of hydrophilic terminations. The first MXene was reported in 2011 at Drexel University's College of Engineering.

Lithium hybrid organic batteries are an energy storage device that combines lithium with an organic polymer. For example, polyaniline vanadium (V) oxide (PAni/V2O5) can be incorporated into the nitroxide-polymer lithium iron phosphate battery, PTMA/LiFePO4. Together, they improve the lithium ion intercalation capacity, cycle life, electrochemical performances, and conductivity of batteries.

In electrochemistry, faradaic impedance is the resistance and capacitance acting jointly at the surface of an electrode of an electrochemical cell. The cell may be operating as either a galvanic cell generating an electric current or inversely as an electrolytic cell using an electric current to drive a chemical reaction. In the simplest nontrivial case faradaic impedance is modeled as a single resistor and single capacitor connected in parallel, as opposed say to in series or as a transmission line with multiple resistors and capacitors.

Lithium–silicon batteries are lithium-ion battery that employ a silicon-based anode and lithium ions as the charge carriers. Silicon based materials generally have a much larger specific capacity, for example 3600 mAh/g for pristine silicon, relative to the standard anode material graphite, which is limited to a maximum theoretical capacity of 372 mAh/g for the fully lithiated state LiC6.

In materials science, vertically aligned carbon nanotube arrays (VANTAs) are a unique microstructure consisting of carbon nanotubes oriented with their longitudinal axis perpendicular to a substrate surface. These VANTAs effectively preserve and often accentuate the unique anisotropic properties of individual carbon nanotubes and possess a morphology that may be precisely controlled. VANTAs are consequently widely useful in a range of current and potential device applications.

Linda Faye Nazar is a Senior Canada Research Chair in Solid State Materials and Distinguished Research Professor of Chemistry at the University of Waterloo. She develops materials for electrochemical energy storage and conversion. Nazar demonstrated that interwoven composites could be used to improve the energy density of lithium–sulphur batteries. She was awarded the 2019 Chemical Institute of Canada Medal.

<span class="mw-page-title-main">Electrochemical quartz crystal microbalance</span>

Electrochemical quartz crystal microbalance (EQCM) is the combination of electrochemistry and quartz crystal microbalance, which was generated in the eighties. Typically, an EQCM device contains an electrochemical cells part and a QCM part. Two electrodes on both sides of the quartz crystal serve two purposes. Firstly, an alternating electric field is generated between the two electrodes for making up the oscillator. Secondly, the electrode contacting electrolyte is used as a working electrode (WE), together with a counter electrode (CE) and a reference electrode (RE), in the potentiostatic circuit constituting the electrochemistry cell. Thus, the working electrode of electrochemistry cell is the sensor of QCM.

References

  1. 1 2 3 4 B. E. Conway (1999), Electrochemical Supercapacitors: Scientific Fundamentals and Technological Applications (in German), Berlin: Springer, pp. 1–8, ISBN   978-0306457364 see also Brian E. Conway in Electrochemistry Encyclopedia: ELECTROCHEMICAL CAPACITORS Their Nature, Function, and Applications Archived 2012-04-30 at the Wayback Machine
  2. ↑ Marin S. Halper, James C. Ellenbogen (March 2006). Supercapacitors: A Brief Overview (PDF) (Technical report). MITRE Nanosystems Group. Archived from the original (PDF) on 2014-02-01. Retrieved 2014-01-20.
  3. ↑ E. Frackowiak, F. Beguin: Carbon Materials For The Electrochemical Storage Of Energy In Capacitors. In: CARBON. 39, 2001, S. 937–950 (PDF [ permanent dead link ]) E. Frackowiak, K. Jurewicz, S. Delpeux, F. Béguin: Nanotubular Materials For Supercapacitors. In: Journal of Power Sources. Volumes 97–98, Juli 2001, S. 822–825, doi : 10.1016/S0378-7753(01)00736-4.
  4. 1 2 Garthwaite, Josie (12 July 2011). "How ultracapacitors work (and why they fall short)". Earth2Tech. GigaOM Network. Archived from the original on 22 November 2012. Retrieved 23 April 2013.
  5. ↑ Conway, Brian Evans, "ELECTROCHEMICAL CAPACITORS Their Nature, Function, and Applications", Electrochemistry Encyclopedia, archived from the original on 2012-04-30
  6. ↑ Frackowiak, Elzbieta; Beguin, Francois (2001). "Carbon Materials For The Electrochemical Storage Of Energy In Capacitors" (PDF). Carbon. 39 (6): 937–950. Bibcode:2001Carbo..39..937F. doi:10.1016/S0008-6223(00)00183-4.[ permanent dead link ]
  7. ↑ Frackowiak, Elzbieta; Jurewicz, K.; Delpeux, S.; Béguin, Francois (July 2001), "Nanotubular Materials For Supercapacitors", Journal of Power Sources, 97–98: 822–825, Bibcode:2001JPS....97..822F, doi:10.1016/S0378-7753(01)00736-4
  8. 1 2 3 B.E. Conway, W.G. Pell, Double-layer and pseudocapacitance types of electrochemical capacitors and their applications to the development of hybrid components
  9. ↑ B. E. Conway, V. Birss, J. Wojtowicz, The role and the utilization of pseudocapacitance for energy storage by supercapacitors, Journal of Power Sources, Volume 66, Issues 1–2, May–June 1997, Pages 1–14
  10. ↑ Conway, B. E. (May 1991). "Transition from 'Supercapacitor' to 'Battery' Behavior in Electrochemical Energy Storage". J. Electrochem. Soc. 138 (6): 1539–1548. Bibcode:1991JElS..138.1539C. doi: 10.1149/1.2085829 .
  11. ↑ P. Simon, Y.Gogotsi, Materials for electrochemical capacitors, nature materials, VOL 7, NOVEMBER 2008
  12. ↑ A.G. Pandolfo, A.F. Hollenkamp, Carbon properties and their role in supercapacitors Archived 2014-01-02 at the Wayback Machine , Journal of Power Sources 157 (2006) 11–27
  13. ↑ B.P. Bakhmatyuk, B.Ya. Venhryn, I.I. Grygorchak, M.M. Micov and S.I. Mudry, INTERCALATION PSEUDO-CAPACITANCE IN CARBON SYSTEMS OF ENERGY STORAGE
  14. ↑ P. Simon, A. Burke, Nanostructured carbons: Double-Layer capacitance and more Archived 2018-12-14 at the Wayback Machine
  15. ↑ Elżbieta Frąckowiak, Francois Beguin, PERGAMON, Carbon 39 (2001) 937–950, Carbon materials for the electrochemical storage of energy in Capacitors
  16. ↑ Why does an ideal capacitor give rise to a rectangular cyclic voltammogram
  17. ↑ Brezesinski, Torsten; Wang, John; Tolbert, Sarah H.; Dunn, Bruce (2010-02-01). "Ordered mesoporous α-MoO3 with iso-oriented nanocrystalline walls for thin-film pseudocapacitors". Nature Materials. 9 (2): 146–151. Bibcode:2010NatMa...9..146B. doi:10.1038/nmat2612. ISSN   1476-1122. PMID   20062048.
  18. ↑ Kim, Il-Hwan; Kim, Jae-Hong; Cho, Byung-Won; Lee, Young-Ho; Kim, Kwang-Bum (2006-06-01). "Synthesis and Electrochemical Characterization of Vanadium Oxide on Carbon Nanotube Film Substrate for Pseudocapacitor Applications". Journal of the Electrochemical Society. 153 (6): A989–A996. Bibcode:2006JElS..153A.989K. doi:10.1149/1.2188307. ISSN   0013-4651.
  19. ↑ Bryan, Aimee M.; Santino, Luciano M.; Lu, Yang; Acharya, Shinjita; D’Arcy, Julio M. (2016-09-13). "Conducting Polymers for Pseudocapacitive Energy Storage". Chemistry of Materials. 28 (17): 5989–5998. doi:10.1021/acs.chemmater.6b01762. ISSN   0897-4756.

Literature

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.