Reversible Charge Storage Research Articles

A facile two-step method for the fabrication of carbon coated manganese oxide nanostructure as a binder-free supercapacitor electrode

In this work, a facile two-step strategy had been developed to synthesize carbon coated manganese oxide for the fabrication of high performance supercapacitor. First, MnO2 nanoflakes were synthesized on Ni foam by a simple chemical deposition method. Then a thin layer of alginate sodium (NaAlg) coated the nanoflakes by electrophoretic deposition (EPD) and was calcined to carbon, which could increase the conductivity and prevent the crystal from dissolving. As a result, the carbon coated manganese oxide displayed an enhanced capacitance of 412 F g−1 at a current density of 1 A g−1 and the capacitance retention maintained 95.7% after 10,000 cycles of charge/discharge, indicating that the binder-free process provided low internal resistance and reversible charge storage behavior.

Role of alloying in Cu2O conversion anode for Li-ion batteries

The successful use of metal oxides as conversion anodes in Li-ion batteries invokes the formation and subsequent reductive decomposition of Li2O. Given the standard reduction potential of Li/Li+ couple, the reduction of Li2O to Li is a thermodynamic challenge. This work investigates the interaction of Li+ ions with a Cu2O matrix computationally using the first principles-based DFT + U methodology. Alloying of Cu and Li takes place more readily than Li2O formation in the early part of the charge cycle. Li2O formation is predicted in the later part of the charge cycle. We attribute the capacity fading observed in oxide conversion anodes to the irreversible accumulation of Li2O and the reversible charge storage capacity delivered by the conversion anodes to alloying. This work indicates that reversible alloying plays a far greater role in the charge–discharge process than is generally acknowledged.

On the unsuspected role of multivalent metal ions on the charge storage of a metal oxide electrode in mild aqueous electrolytes.

Insertion mechanisms of multivalent ions in transition metal oxide cathodes are poorly understood and subject to controversy and debate, especially when performed in aqueous electrolytes. To address this issue, we have here investigated the reversible reduction of nanostructured amorphous TiO2 electrodes by spectroelectrochemistry in mild aqueous electrolytes containing either a multivalent metal salt as AlCl3 or a weak organic acid as acetic acid. Our results show that the reversible charge storage in TiO2 is thermodynamically and kinetically indistinguishable when carried out in either an Al3+- or acetic acid-based electrolyte, both leading under similar conditions of pH and concentrations to an almost identical maximal charge storage of ∼115 mA h g-1. These observations are in agreement with a mechanism where the inserting/deinserting cation is the proton and not the multivalent metal cation. Analysis of the data also demonstrates that the proton source is the Brønsted weak acid present in the aqueous electrolyte, i.e. either the acetic acid or the aquo metal ion complex generated from solvation of Al3+ (i.e. [Al(H2O)6]3+). Such a proton-coupled charge storage mechanism is also found to occur with other multivalent metal ions such as Zn2+ and Mn2+, albeit with a lower efficiency than Al3+, an effect we have attributed to the lower acidity of [Zn(H2O)6]2+ and [Mn(H2O)6]2+. These findings are of fundamental importance because they shed new light on previous studies assuming reversible Al3+-insertion into metal oxides, and, more generally, they highlight the unsuspected proton donor role played by multivalent metal cations commonly involved in rechargeable aqueous batteries.

Vanillin decorated chitosan as electrode material for sustainable energy storage.

Energy storage materials made from bioresources are crucial to fulfil the need for truly sustainable energy storage. In this work, vanillin, being a lignin-derived molecule, is coupled to chitosan, a biobased polymer backbone, and used as a redox active electrode material. The structure of those electrodes is highly defined, leading to better product security than in lignin based electrodes, which have been presented as sustainable electrodes in the past. With over 60% of saccharide units in chitosan functionalised by vanillin, the concentration of redox functionalities in the copolymer is significantly higher than in lignin materials. Composites with carbon black require no further binders or additives to be used as electrode material and show reversible charge storage up to 80 mA h g−1 (respective to the total electrode material) and good stability. Consequently, these electrodes are amongst the best performing electrodes made from regrown organic matter.

N-graphene motivated SnO2@SnS2 heterostructure quantum dots for high performance lithium/sodium storage

Nanostructure engineering of the active materials including decreasing the material feature size, or designing appropriate heterostructures, offers immense promise in improving the charge storage kinetics, and enhancing the practical performance in this work, we report a new synthesis of SnO2@SnS2 heterostructured quantum dots (HQDs) uniformly anchored on N-doped graphene (SnO2@SnS2@NG), promoted by the electrostatic interaction between NG and Sn4+. The faster electron transport kinetics than SnO2 and SnS2 can be achieved at heterointerfaces of SnO2@SnS2 through DFT calculation analysis. And, the SnO2@SnS2 HQDs (3–5 nm) can shorten Li/Na ion diffusion pathway greatly, while the NG substrate can provide excellent electrical conductivity and good structural stability. As a result, the ion diffusion coefficient of this HQDs structure is 60 folds higher than that of bare SnO2@SnS2 nanoparticle. High reversible charge storage capacities are achieved for both LIBs (1081 mA h g−1 at 0.05 A g−1, 343 mA h g−1 at 5 A g−1) and SIBs (450 mA h g−1 at 0.05 A g−1, 75 mA h g−1 at 5 A g−1).

Electrochemical performance of CH3COONa aqueous electrolytes

Supercapacitors are a promising high-power energy storage device due to highly reversible charge-storage process and long cyclic stability. However, the major limitation of supercapacitors lies in their energy density. Here, a high voltage carbon-based supercapacitor is built by using 2 M CH3COONa aqueous solution as electrolyte. In three-electrode system, this paper uses the potentiostatic polarization curves to study the 1.8 V high operating voltage window with the nitrogen-self-doped mesoporous carbon materials (FBNC-700) as electrode materials. In two-electrode system, the FBNC-700 displayed a specific capacitance of 111 F g−1 at a current density of 0.5 A g−1 in 2 M CH3COONa aqueous electrolyte. The 2 M CH3COONa aqueous electrolytes which can improve the energy density to 3.8 times than the 1 M H2SO4 aqueous electrolyte exhibits an excellent performance. Also, following 5000 cycles at a current density of 1 A g−1, the FBNC-700 had good stability with 74.2% capacitance retention. As an aqueous electrolyte, 2 M CH3COONa which has the 1.8 V high operating voltage window can improve the energy density in carbon-based supercapactor.

Co3Sn2/SnO2 heterostructures building double shell micro-cubes wrapped in three-dimensional graphene matrix as promising anode materials for lithium-ion and sodium-ion batteries

A double shell micro-cube assembled by nanosized Co3Sn2/SnO2 heterostructures with amorphous carbon layers wrapped in three-dimensional graphene matrix (DS-Co3Sn2/SnO2@C@GN) is successfully synthesized via a series of combined procedures containing co-precipitation, hydrothermal reaction for carbon coating, stirring for mixing and calcination. Compared to the single shell (SS-) and yolk-shell (YS-) structure, this unique hierarchical architecture has several obvious advantages to ameliorate the battery performances, including (1) huge inner voids and plenty of mesopores, (2) the synergetic effect of amorphous carbon and graphene, (3) the internal potential created by the formation of Co3Sn2/SnO2 heterojunction and (4) enhanced structural stability of this micro-cube by chemical bond. When used as the anode electrode of lithium ion batteries (LIBs), it exhibits the superior performance with a reversible charge storage capacity of 744 mA g−1 after 100 cycles and 605 mA g−1 after 300 cycles at a current density of 0.1 A g−1. Meanwhile, the DS-Co3Sn2/SnO2@C@GN micro-cube also shows good sodium storage capacity.

Soluble Supercapacitors: Large and Reversible Charge Storage in Colloidal Iron-Doped ZnO Nanocrystals.

Colloidal ZnO semiconductor nanocrystals have previously been shown to accumulate multiple delocalized conduction-band electrons under chemical, electrochemical, or photochemical reducing conditions, leading to emergent semimetallic characteristics such as quantum plasmon resonances and raising prospects for application in multielectron redox transformations. Here, we demonstrate a dramatic enhancement in the capacitance of colloidal ZnO nanocrystals through aliovalent Fe3+-doping. Very high areal and volumetric capacitances (33 μF cm-2, 233 F cm-3) are achieved in Zn0.99Fe0.01O nanocrystals that rival those of the best supercapacitors used in commercial energy-storage devices. The redox properties of these nanocrystals are probed by potentiometric titration and optical spectroscopy. These data indicate an equilibrium between electron localization by Fe3+ dopants and electron delocalization within the ZnO conduction band, allowing facile reversible charge storage and removal. As "soluble supercapacitors", colloidal iron-doped ZnO nanocrystals constitute a promising class of solution-processable electronic materials with large charge-storage capacity attractive for future energy-storage applications.

Diffusion-Controlled Faradaic Charge Storage in High-Performance Solid Electrolyte-Gated Zinc Oxide Thin-Film Transistors.

An electrochemical device capable of manifesting reversible charge storage at the interface of an active layer offers formidable advantages, such as low switching energy and long retention time, in realizing synaptic behavior for ultralow power neuromorphic systems. Contrary to a supercapacitor-based field-effect device that is prone to low memory retention due to fast discharge, a solid electrolyte-gated ZnO thin-film device exhibiting a battery-controlled charge storage mechanism via mobile charges at its interface with tantalum oxide is demonstrated. Analysis via cyclic voltammetry and chronoamperometry uniquely distinguishes the battery behavior of these devices, with an electromotive force generated due to polarization of charges strongly dependent on the scan rate of the applied voltage. The Faradaic-type diffusion-controlled charge storage mechanism exhibited by these devices is capable of delivering robust enhancement in the channel conductance and leads to a superior ON-OFF ratio of 108-109. The nonvolatile behavior of the interface charge storage and slow diffusion of ions is utilized in efficiently emulating spike timing-dependent plasticity (STDP) at similar time scales of biological synapses and unveils the possibility of STDP behavior using multiple in-plane gates that alleviate additional requirement of waveform-shaping circuits.

Proton Ion Exchange Reaction in Li3IrO4: A Way to New H3+xIrO4 Phases Electrochemically Active in Both Aqueous and Nonaqueous Electrolytes

AbstractProgress over the past decade in Li‐insertion compounds has led to a new class of Li‐rich layered oxide electrodes cumulating both cationic and anionic redox processes. Pertaining to this new class of materials are the Li/Na iridate phases, which present a rich crystal chemistry. This work reports on a new protonic iridate phase H3+xIrO4 having a layered structure obtained by room temperature acid‐leaching of Li3IrO4. This new phase shows reversible charge storage properties of 1.5 e− per Ir atom with high rate capabilities in both nonaqueous (vs Li+/Li) and aqueous (vs capacitive carbon) media. It is demonstrated that Li‐insertion in carbonate LiPF6‐based electrolyte occurs through a classical reduction process (Ir5+ ↔ Ir3+), which is accompanied by a well‐defined structural transition. In concentrated H2SO4 electrolyte, this work provides evidence that the overall capacity of 1.7 H+ per Ir results from two additive redox processes with the low potential one showing ohmic limitations. Altogether, the room temperature protonation approach, which can be generalized to various Li‐rich phases containing either 3d, 4d or 5d metals, offers great opportunities for the judicious design of attractive electrode materials.

Cobalt selenide decorated carbon spheres for excellent cycling performance of sodium ion batteries

Development of electrode materials with high capacity, superior rate performance, long cycle life and low cost is critical to commercialize sodium ion batteries (SIBs). Herein, a unique composite consisted of cobalt selenide (Co0.89Se) nanoparticles (3–10nm) embedded in carbon spheres (CoSe@CSs) is presented as anode for SIBs. The exclusive structure of CoSe@CSs enables the pseudocapacitive charge storage, improves the electronic properties and provides buffer for volumetric changes during the repeated charge-discharge processes. The composite with an average diameter of ~100nm, denoted as CoSe@100CSs, presented the best electrochemical performance (with a reversible charge storage capacity of 554mAh g-1 after 50 cycles at a rate of 100mAg-1) when compared with composites of 300nm and 500nm diameters and also pure CoSe. Additional to high storage capacity, the CoSe@100CSs also showed excellent rate capability and ultra-long cycling life when examined at higher discharge rates. Storage capacities are as high as 350mAh g-1 at the rate of 1000mAg-1 and 260mAh g-1 at the rate of 4000mAg-1 after 4000 and even 10,000 cycles, respectively. Hence, due to this synergetic effect of uniformly distributed cobalt selenide nanoparticles and carbon matrix, the CoSe@CSs composite exhibits exceptional electrochemical performance for SIBs. This strategy is expected to open up new methodologies for the development of advanced electrode materials of high performance SIBs.

(Invited) Development of Flexible Conductive Polymer Electrodes for Recording and Stimulation of Neural Tissue

We describe the development of thin, flexible conductive polymer electrodes for recording and stimulation of excitable tissue including brain, spinal cord, peripheral nerve, and muscle. The electrode material characteristics are intended to mitigate the foreign body response. Manufacturing is based on 3-D robotic deposition of alternating layers of insulating polymer, and polymer doped with electrically conductive particles forming the electrodes and interconnections. The robot can produce multilayer structures and supports synthesis of the electrode array with integrated electronics at low cost. We have performed in vivo and in vitro testing, including flexural tests which demonstrate electrical and mechanical reliability for over 100 million flexions. The capacitive nature of the electrodes provides reversible charge storage capacity that is comparable with other high charge capacity materials. Manufacturing Process: The robotic system first deposits an insulating substrate using a silicone co-polymer which is well established as a chronic implant material. After the substrate cures, a layer of conductive ink based on polymer doped with electrically conductive particles is deposited to form the electrodes and interconnections. Next, an overcoat of insulating polymer is deposited. This process may be repeated to form multilayer structures, similar to the process of printed circuit board manufacturing. Because the ink is mostly polymer by volume fraction, an entire structure has mechanical properties of a homogeneous polymer. This mechanical matching of insulating and conducting phases provides high flexibility and flexural durability. Composite structures with features as small as 100 µm trace width, 200 µm pitch and 30 µm thin insulating layers are achieved with high reproducibility including optional connection directly onto printed circuit boards. Electrode Testing : Mechanical and electrical performance of the devices has been verified through mechanical compression, stretch, and bend tests, and accelerated lifetime soak testing. These stress tests have verified the conductivity of the traces and electrodes and the insulation of the polymer for over 100 million bend cycles (tested per EN 45502-2) and lifetimes equivalent to over 400 days in vivo. The electrodes have also been successfully validated in chronic in vivo studies in rat, cat, rabbit and pig models. Electrical Characterization : DC resistances of the ECoG array vary with trace length and thickness, and are generally on the order of several hundred ohms over several inches of trace. Electrical impedance spectroscopy (EIS) was performed after soaking the arrays in saline solution for at least 12 h, and yielded trace-to-saline impedances below 10 kΩ for frequencies in the range of 0.2 Hz to 1 MHz. Cyclic voltammetry was performed with a Pt counter electrode and a fresh Ag/AgCl reference electrode with a scan rate of 20 mV/s. The reversible charge storage capacity (RCSC) increased with cycling as is common with other materials used for stimulation. After several cycles, the RCSC is on the order of 1 – 1.5 mC/cm2, comparable with other high charge storage capacity materials. This is consistent with the capacitive nature of the platinum embedded within dielectric polymer. Demonstration of Chronic Wireless ECoG Recording : We have developed a wireless recording system used in conjunction with the flexible electrode array. A four-electrode array was implanted subdurally over sensory cortex in swine for chronic ECoG monitoring. Leads from the array passed to a subcutaneous transmitter placed between the scapulae. The transmitter sent data to an external transceiver via infrared transmission. We demonstrated wireless transmission of evoked ECoG recordings over 63 days as the paw was electrically stimulated.

Na‐Ion Intercalation and Charge Storage Mechanism in 2D Vanadium Carbide

Abstract2D vanadium carbide MXene containing surface functional groups (denoted as V2CTx, where Tx are surface functional groups) is synthesized and studied as anode material for Na‐ion batteries. V2CTx anode exhibits reversible charge storage with good cycling stability and high rate capability through electrochemical test. The charge storage mechanism of V2CTx material during Na+ intercalation/deintercalation and the redox reaction of vanadium are studied using a combination of synchrotron based X‐ray diffraction, hard X‐ray absorption near edge spectroscopy (XANES), and soft X‐ray absorption spectroscopy (sXAS). Experimental evidence of a major contribution of redox reaction of vanadium to the charge storage and the reversible capacity of V2CTx during sodiation/desodiation process are provided through V K‐edge XANES and V L2,3‐edge sXAS results. A correlation between the CO32− content and the Na+ intercalation/deintercalation states in the V2CTx electrode observed from C and O K‐edge in sXAS results implies that some additional charge storage reactions may take place between the Na+‐intercalated V2CTx and the carbonate‐based nonaqueous electrolyte. The results of this study provide valuable information for the further studies on V2CTx as anode material for Na‐ion batteries and capacitors.

Dissolvable Conducting Polymers for Electrochemical Energy Storage

Conducting polymers have attracted great interest as energy storage materials in supercapacitors and Li-ion batteries. Polypyrrole in particular is well known for its reversible capacitive charge storage, ease of synthesis, and potential application as a robust, conductive coating for Si-based anodes.1,2 While much research on conducting polymer energy storage has focused on improving energy density and cycle lifetime, conducting polymers are also promising materials for environmentally-friendly, transient, and/or biocompatible energy storage applications.3 An important first step in the advancement of environmentally-friendly, biodegradable energy storage devices is developing materials that break down under mild conditions. Previous work on conducting polymer derivatives indicates that side-chain moieties can reduce polymer crosslinking, enabling conducting polymers to dissolve easily under physiological conditions.4 Here we present for the first time a repeating polymer of methyl 1H-pyrrole-3-carboxylate monomer (“MPC polymer”) as a supercapacitor energy storage material, and its ability to dissolve in a mild aqueous environment. This work is, to the best of our knowledge, the first demonstration of electrochemical energy storage using a dissolvable conducting polymer derivative and thus represents an important contribution to the field of transient, biocompatible energy storage materials. Figure 1 provides a conceptual illustration of supercapacitor energy storage using MPC polymer vs. polypyrrole. Both polymers were electrodeposited onto a Si substrate with Cr/Au coating from a 0.1 M solution of the corresponding monomer in 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF6) in acetonitrile. Cyclic voltammetry measurements conducted in 0.1 M TBAPF6 electrolyte in acetonitrile indicate comparable charge storage abilities for MPC polymer and polypyrrole, with capacitances of 0.98 mF/cm2 and 1.75 mF/cm2, respectively, for the planar electrodes. Figure 3 compares the solubility of MPC polymer and polypyrrole in Tris acetate-EDTA buffer solution (pH 8.2) at 37 oC. Within one hour, most of the MPC polymer film had dissolved, compared to the polypyrrole electrode which remained unchanged after four hours in the buffer solution. These results demonstrate that conducting polymer derivatives can function as dissolvable energy storage materials – an important first step in realizing fully biodegradable electrochemical energy storage materials. Detailed characterization of MPC polymer and its capacitive energy storage performance will be presented, including FT-IR spectroscopy characterization, capacitive charge-discharge cycle life measurements, and impedance characterization. R. Warren, F. Sammoura, K.S. Teh, A. Kozinda, X. Zang, and L. Lin, Sens. Actuators, A, 231, 65 (2015).F.-H. Du, B. Li, W. Fu, Y.-J. Xiong, K.-X. Wang, and J.-S. Chen, Adv. Mater., 26, 6145 (2014).L. Yin, X. Huang, H. Xu, Y. Zhang, J. Lam, J. Cheng, and J. Rogers, Adv. Mater., 26, 3879 (2014).A. Zelikin, D. Lynn, J. Farhadi, I. Martin, V. Shastri, and R. Langer, Angew. Chem. Int. Ed., 41, 141 (2002). Figure 1

Low Molecular Weight Gelators Bearing Electroactive Groups as Cathode Materials for Rechargeable Batteries

SummaryLow molecular weight gelators bearing 2,2,6,6‐tetramethyl‐piperidine‐1‐oxyl (TEMPO) were synthesized and demonstrated to have reversible electrochemical redox properties. The gelation tests showed that the compounds have excellent gelation properties in γ‐butyrolactone and propylene carbonate. Atomic force microscopy and transmission electron microscopy images showed the 3D network fibrous structure with an average diameter of 20–50 nm. Fast and reversible charge storage capabilities were established for the gelators, with an average output voltage of 4.8 V.

Generic Synthesis of Carbon Nanotube Branches on Metal Oxide Arrays Exhibiting Stable High-Rate and Long-Cycle Sodium-Ion Storage.

A new and generic strategy to construct interwoven carbon nanotube (CNT) branches on various metal oxide nanostructure arrays (exemplified by V2 O3 nanoflakes, Co3 O4 nanowires, Co3 O4 -CoTiO3 composite nanotubes, and ZnO microrods), in order to enhance their electrochemical performance, is demonstrated for the first time. In the second part, the V2 O3 /CNTs core/branch composite arrays as the host for Na(+) storage are investigated in detail. This V2 O3 /CNTs hybrid electrode achieves a reversible charge storage capacity of 612 mAh g(-1) at 0.1 A g(-1) and outstanding high-rate cycling stability (a capacity retention of 100% after 6000 cycles at 2 A g(-1) , and 70% after 10 000 cycles at 10 A g(-1) ). Kinetics analysis reveals that the Na(+) storage is a pseudocapacitive dominating process and the CNTs improve the levels of pseudocapacitive energy by providing a conductive network.

(Invited) Interfacial and Transport Phenomena in Hybrid Pseudocapacitors

Electrochemical capacitors have attracted significant attention in recent years due to their promise as electrical energy storage devices for high energy and power applications. They are typically classified as either electric double layer capacitors (EDLCs) or pseudocapacitors depending on the energy storage mechanism. EDLCs store energy physically in the electric double layers (EDLs) forming near the electrode/electrolyte interfaces. Thus, EDLCs feature highly reversible charge storage and long cycle life. However, their energy density remains low compared with that of batteries. On the other hand, pseudocapacitors store energy via the electric double layers as well as via reversible oxidation-reduction (redox) reactions with or without insertion or intercalation. Pseudocapacitors tend to feature larger capacitances and energy densities than EDLCs because the amount of charge they can store is not limited by the surface area of the electrode/electrolyte interface. Finally, hybrid pseudocapacitors are devices combining a pseudocapacitive electrode made of a porous transition metal oxide (e.g., RuO2, MnO2, Nb2O5, MoO3) and an EDLC-type electrode typically made of porous carbon. This invited talk will present recent advances in physical modeling of interfacial, transport, and electrochemical phenomena in pseudocapacitors. It aims to provide physical interpretation of cyclic voltammograms obtained experimentally either from hybrid pseudocapacitors or from pseudocapacitive electrodes using three-electrode systems. First, it will present a continuum model simultaneously accounting for (i) charge transport in electrodes and electrolyte, (ii) the dynamics of the electric double layer, (iii) steric repulsion due to finite ion sizes, (iv) redox reactions, and (v) intercalation. Second, it will report selected numerical simulations of CV curves for different electrode thickness and electron and ion transport properties in the electrodes and electrolyte, representative of actual situations. These results will be used to elucidate the respective contributions of faradaic reactions and electric double layer formation to charge storage in pseudocapacitors. Particular attention will be paid to the so-called b-value characterizing the power law evolution of the total current with respect to scan rate for a given potential. Special effort will be made to systematically compare model predictions with experimental data.

Fast Electron Transfer Exchange at Self-Assembled Monolayers of Organometallic Ruthenium(II) σ-Arylacetylide Complexes.

A new series of ruthenium organometallic carbon-rich complexes, exhibiting fast electron transfer kinetics combined to a low oxidation potential, was synthesized for self-assembled monolayer (SAM) formation on gold surfaces. The molecules consist of highly conjugated ruthenium(II) mono(σ-arylacetylide) or bis(σ-arylacetylide) complexes functionalized with different bridge units with specific (protected) anchoring groups that possess high affinity for gold, such as thiol, carbodithioate, and isocyanide. Single component and mixed SAMs were prepared and fully characterized by wettability studies, infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), and electrochemical analyses. By applying the Laviron's formalism, fast electron transfer kinetics (≈10(4) s(-1)) were found at the derived self-assemblies while no significant effect could have been evidenced with variation of the bridging unit and of the anchoring moiety. Interestingly, a hexyl aliphatic spacer in the bridging unit with a thiol group and dilution with suitable nonelectroactive thiols lead to better SAM organization and packing, in comparison with undiluted complexes with shorter spacers. Such features make these compounds suitable alternatives to the widely used ferrocene center as redox-active building blocks for reversible charge storage devices.

Efficient charge transport of a radical polyether/SWCNT composite electrode for an organic radical battery with high charge-storage density

A fast and reversible charge storage capability was established for the radical polyether/SWCNT composite layer with a large layer thickness of several tens of micrometres despite the low SWCNT content of 10%.

A new design of organic radical batteries (ORBs): carbon nanotube buckypaper electrode functionalized by electrografting.

A novel hybrid material displaying a fast and reversible charge storage capability is prepared by electrografting of an alkoxyamine-bearing acrylate onto a carbon nanotube buckypaper, followed by the quantitative generation of an electroactive polynitroxide.