Electrodes For Energy Storage Applications Research Articles

Hydrothermally synthesized MnCo2O4 nanoparticles for advanced energy storage applications

We observed the impact of reaction time on the electrochemical performance of MnCo2O4 nanoparticles, specifically focusing on the overgrowth of nanoparticles over the nanostructure. We characterized the synthesized nanomaterial using XRD, SEM, and XPS techniques to analyze its crystal structure, surface microstructure, and chemical states, respectively. The electrode prepared via a 5-hour hydrothermal reaction exhibited an outstanding areal capacitance of 144 mF/cm2 at a current density of 1A/g. Furthermore, it demonstrated an areal energy density of 4.1 μWh/cm2 at a power density of 0.225 mW/cm2. We assembled an asymmetric supercapacitor (ASC) configuration, MCO-5 h//AC, using MCO-5 h and activated carbon (AC), which showcased exceptional areal capacitance, areal energy density, and power density. These characteristics make it highly suitable for practical applications in energy storage. Overall, our findings highlight MCO-5 h as a promising electrode for energy storage applications.

Candle soot carbon-Co3O4 nanofibers composite as a binder-free electrode for high-performance supercapacitor application: An experimental and theoretical investigation

Extensive research has been conducted on nanostructured metal oxide electrodes for energy storage applications, particularly in supercapacitors, owing to their high specific capacitance. However, a major hindrance to their commercialization is their limited life cycles. To address this issue, incorporating carbon allotropes as a conductive support to enhance the electrode's stability has been explored. In the current work, a novel composite material was synthesized by combining candle soot carbon with cobalt oxide (Co3O4) to create a highly efficient electrode. The optimal composite, with a 2 wt% of candle soot carbon to Co3O4, exhibited utmost specific capacitance (997.5 Fg−1) at 1 Ag−1. After subjecting both electrodes to 10,000 cycles of repetitive charge and discharge, the composite demonstrated a capacitance retention of 83.3 %, while the Co3O4 electrode only achieved 75 % under identical conditions. Additionally, Density Functional Theory (DFT) investigations were performed to elucidate the improved charge-storing capacities of the composite electrode. The computed density of states indicates enrichment of energy states near the Fermi level in the composite when seen to pristine Co3O4. The Partial Density of States (PDOS) analysis illustrates the transportation of charge from the carbon p orbital (candle soot carbon) to the Co d orbital (Co3O4), validating the conductivity improvement in the hybrid configuration, which benefits from enhanced charge storage performance. Overall, the composite material is promising for hybrid supercapacitors, especially due to the incorporation of candle soot carbon as one of its components. It not only enhances the performance of the supercapacitor but also offers the advantage of being a renewable material derived from waste materials. This combination makes the composite an appealing and sustainable choice for next-generation energy storage devices.

Template-assisted synthesis of hollow anthraquinone-based covalent organic frameworks for aqueous zinc-ion hybrid supercapacitors.

Anthraquinone-based hollow COFs were synthesized via a template-assisted method involving polystyrene nanospheres as the hard template, which enabled doubling the specific capacitance and energy density compared to non-templated COFs. Our approach can be extended to other COFs, offering a promising strategy for enhancing the performance of COF-based electrodes in energy storage applications.

Facile synthesis of morphology-controlled hybrid structure of ZnCo2O4 nanosheets and nanowires for high-performance asymmetric supercapacitors.

Controllable synthesis of electrode materials with desirable morphology and size is of significant importance and challenging for high-performance supercapacitors. Herein, we propose an efficient hydrothermal approach to controllable synthesis of hierarchical porous three-dimensional (3D) ZnCo2O4 composite films directly on Ni foam substrates. The composite films consisted of two-dimensional (2D) nanosheets array anchored with one-dimensional (1D) nanowires. The morphologies of ZnCo2O4 arrays can be easily controlled by adjusting the concentration of NH4F. The effect of NH4F in the formation of these 3D hierarchical porous ZnCo2O4 nanosheets@nanowires films is systematically investigated based on the NH4F-independent experiments. This unique 3D hierarchical structure can help enlarge the electroactive surface area, accelerate the ion and electron transfer, and accommodate structural strain. The as-prepared hierarchical porous ZnCo2O4 nanosheets@nanowires films exhibited inspiring electrochemical performance with high specific capacitance of 1289.6 and 743.2 F g-1 at the current density of 1 and 30 A g-1, respectively, and a remarkable long cycle stability with 86.8% capacity retention after 10 000 cycles at the current density of 1 A g-1. Furthermore, the assembled asymmetric supercapacitor using the as-prepared ZnCo2O4 nanosheets@nanowires films as the positive electrode and active carbon as negative electrode delivered a high energy density of 39.7 W h kg-1 at a power density of 400 W kg-1. Our results show that these unique hierarchical porous 3D ZnCo2O4 nanosheets@nanowires films are promising candidates as high-performance electrodes for energy storage applications.

Understanding the Role of the Binder on the Microstructure and Properties of PTFE-Based Solvent-Free Electrodes

Solvent-free processing, also known as dry-processing refers to a group of manufacturing methods which avoid the use of solvents in the production of electrodes for energy storage applications. This concept has been around for more than a decade, although its popularity has increased dramatically over the last couple of years after the purchase of Maxwell technologies by Tesla. Maxwell patented a novel processing route which involves dry mixing the active material powder with a PTFE binder to form an electrode without the use of any solvent. Solvent-free processes have significant advantages in terms of sustainability, safety and cost over conventional slurry casting.A detailed analysis of the slurry casting process showed that around a quarter of the total manufacturing cost of the battery pack originated from solvent associated steps. Avoiding the use of toxic and flammable solvents such as N-methyl Pyrrolidone (NMP) also naturally leads to an improvement in the safety of the manufacturing environment. More importantly, it was reported that the manufacturing steps associated with solvent removal accounted for half of the embodied energy of a typical Li-ion battery. The embodied energy of a Li-ion battery is a crucial figure of merit in terms of sustainability which is too often neglected. To put things into perspective, Volvo has recently published a carbon footprint report for their fully electric Volvo C40 Recharge and compared it to their internal combustion engine (ICE) equivalent, the XC40. They reported that the production of the electric version generated 26 tonnes of CO2-equivalents compared to 16 tonnes for the ICE model, representing a large increase of almost 70% in the embodied energy of the car. Novel and more sustainable manufacturing processes are urgently needed to reduce as much as possible the embodied energy of Li-ion batteries and make them more sustainable to enable a durable green energy transition.Although the concept of solvent-free processing seems attractive, most of its current development is happening behind closed doors in industry. However, an in-depth characterisation of this new type of electrodes and a comparison with conventional slurry cast electrodes would be beneficial to understand the challenges and opportunities brought by these new systems and help accelerate their development on a larger scale. Within the family of solvent-free processes, three main techniques have emerged: dry painting, powder injection molding and PTFE-fibrillation. Studies dedicated to electrodes based on PTFE-fibrillation are rare and often focused on solid-state systems. In order to dispel some of the mystery surrounding the novel microstructures obtained through the PTFE-fibrillation process and their performance, this work focuses on the characterisation of these new electrodes and investigate the role of the PTFE binder on the microstructure and electrochemical performance of solvent-free electrodes. Our results highlight the crucial importance of the PTFE binder on the mechanical properties of the solvent-free electrodes and reveal how the peculiar mechanical behavior of these composite electrodes during the manufacturing process influences the final microstructure of the electrodes and their electrochemical performance. This work presents a deep insight into PTFE-based solvent-free electrodes by investigating their microstructure, mechanical and electrochemical properties using advanced characterization techniques including High Resolution Analytical Scanning Electron Microscopy, X-Ray Computed Tomography, Electrochemical Impedance Spectroscopy and mechanical testing.

Solvent-Assisted Morphology-Induced Nickel Metal–Organic Framework as a Highly Efficient Electrode for Energy Storage Application

Solvent-Assisted Morphology-Induced Nickel Metal–Organic Framework as a Highly Efficient Electrode for Energy Storage Application

Elucidating the Role of Copper-Induced Mixed Phases on the Electrochemical Performance of Mn-Based Thin-Film Electrodes.

Manganese oxide is a fascinating material for use as a thin-film electrode in supercapacitors. Herein, the consequences of copper incorporation on spray pyrolyzed manganese oxide thin films and their electrochemical performance were investigated. The Cu-incorporated manganese oxide thin films were deposited by spray pyrolysis, and their structural and electrochemical properties were thoroughly evaluated. The formation of the spinel Mn3O4 phase with effective Cu incorporation was confirmed by X-ray diffraction investigation. Through Raman studies, it was noticed that mixed phases of manganese oxide tend to form after Cu incorporation, and this result was also reflected in X-ray photoelectron spectroscopic studies. The surface morphology and roughness were also altered by the addition of copper. However, electrochemical measurements implied a reduction in the specific capacitance upon copper inclusion. The cyclic voltammetry test indicated a specific capacitance of 132 F/g for Mn3O4 electrodes, but a substantial drop for copper-incorporated samples due to the mixed manganese phase. The decremental tendency was further supported by galvanostatic charge-discharge studies and electrochemical impedance spectroscopic measurements. These results provide valuable insights into the effects of copper addition in manganese oxide thin-film-based electrodes for energy storage applications.

A novel double perovskite Dy2CoMnO6 as supercapacitor electrode with efficient electrochemical performance

Novel double perovskite oxide Dy2CoMnO6 (DCMO) based electrodes were fabricated for supercapacitor application. Structural studies indicate a monoclinic structure (space group: P21/n). The evidence of structural distortion is observed due to the large extent of decentralization of oxygen electron clouds around Co and Mn atoms in YZ and XZ directions. Micron-sized particles of DCMO constitutes a flat surface of electrodes for faster electrochemical reaction. Room temperature electrochemical performance was investigated using three electrodes set up. Cyclic voltammograms (CV) and Galvanostatic charging–discharging (GCD) curves display significant specific capacitance with super cyclic stability as electrodes. The DCMO electrode shows 87 % cyclic stability over 10,000 cycles. This work produces efficient and stable double perovskite oxide DCMO as electrodes for energy storage applications.

Binder-free hydrothermal approach to fabricate high-performance zinc phosphate electrode for energy storage applications

Metal phosphates are an emerging class of materials with large porosity that endows them with high specific capacity and ionic conductivity. However, the binder and carbon additive are required to fabricate the electrodes which adds extra expenditure to the supercapacitor's overall fabrication cost. The binder-free electrode fabrication provides a hope to eliminate the need for binders and hence the carbon additive for supercapacitor applications. In this work, a binder-free zinc phosphate hydrate (ZPOH) based electrode is fabricated using a cost-effective hydrothermal method. Two additional electrodes were also fabricated – one without carbon additive (ZPOWCB) and another with the addition of carbon additive (ZPOCB) using the conventional slurry preparation method. ZPOH electrode showed remarkable enhancement in the specific capacity compared to the other two electrodes as it achieved a specific capacity of 433 C/g at a current density of 2 A/g. Moreover, ZPOH also showed negligible charge transfer resistance (Rct), depicting good electrolyte ions interaction with the active material. Hence, the easy and simple binder-free hydrothermal approach is more suitable for preparing electrode materials for energy storage applications.

Hierarchical polyaniline/copper cobalt ferrite nanocomposites for high performance supercapacitor electrode

Increasing energy demand needs efficient energy storage devices, especially for mobile applications and wearable electronics. Conducting polymer based nanocomposite offers excellent charge transfer mechanism with high energy storage ability. Herein, we report preparation of polyaniline/copper cobalt ferrite (PANI/CCF) based nanocomposites to fabricate supercapacitor electrodes. In-situ polymerization of PANI ensures the formation of a well-mixed nanocomposite of PANI and CCF. Detailed structural and morphological analysis reveal the formation of a core-shell type structure with CCF as the core and PANI as the shell. The core-shell structure was formed due to the presence of a synergistic interaction between PANI and CCF. Particle size distribution shows a well distribution with an average size ~100–120 nm, contributing significantly towards high energy density at high power density. The supercapacitor electrode based on 8:1 material shows significantly high capacitance of 408.8 F g−1 at a scan rate of 5 mV s−1 and 460.1 F g−1 at 0.5 A g−1 current density. The energy storage capacity enhanced significantly for 8:1 weight ratio of PANI and CCF. The PANI/CCF 8:1 nanocomposite shows energy density of 23 and 18.2 W h kg−1 at power density of 150 and 1500 W kg−1, respectively with a good cyclic life (~91 % retention after the 1500 cycle). Consequently, PANI/CCF 8:1 nanocomposite has excellent potential for supercapacitor electrodes for energy storage applications.

Graphite Paper-based Device for Energy Storage Application

The demand for versatile flexible energy storage device has arisen due to their potential, application in wearable and portable electronic product. This study presents the characterization of graphite paper-based capacitor and supercapacitor that are produced utilising commercially available pencils to draw a design by developing cheap, green, and reliable low profile electrical electrodes. The objectives of this study are to design graphite paper-based electrodes for energy storage application, characterize the physical properties of the electrodes and electrical properties of the device. Material characterization have been performed including morphology analysis of the electrodes using field emission scanning electron microscope (FESEM), compositional structures by using Energy dispersive X-ray spectroscopy (EDX) and chemical properties of the graphitic electrodes using Raman spectroscopy. Next, the electrical performance of the pencil drawn capacitor and supercapacitor have been performed. It is found that the Acidic G/PANI-Paper supercapacitor sample shows the best electrical performance in terms of lowest resistance with 0.59 MΩ, 1.12 MΩ, 1.8 MΩ and highest capacitance with 27.5 μF, 38.1 μF, 55.25 μF for respective 6 cm2, 8 cm2 and 10 cm2 area size. These characteristics show that the graphite-paper based device has a great potential in flexible energy storage applications.

Laser-induced transient conversion of rhodochrosite/polyimide into multifunctional MnO2/graphene electrodes for energy storage applications

Laser-induced graphene (LIG) has been extensively investigated for electrochemical energy storage due to its easy synthesis and highly conductive nature. However, the limited charge accumulation in LIG usually leads to significantly low energy densities. In this work, we report a novel strategy to directly transform natural rhodochrosite into ultrafine manganese dioxide (MnO2) nanoparticles (NPs) in the polyimide (PI) substrate for high-performance micro-supercapacitors (MSCs) and lithium-ion batteries (LIBs) through a scalable and cost-effective laser processing method. Specifically, laser treatment on rhodochrosite/polyimide precursors induces the thermal explosion, which splits rhodochrosite (10 μm) into MnO2 NPs (12–16 nm) on the carbon matrix of LIG due to the sputtering effect. Benefiting from largely exposed active sites from the ultrafine MnO2 and the synergetic effect from highly conductive LIG, the MnO2/LIG MSCs show a high specific capacitance of 544.0 F g−1 (154.3 mF cm−2; 14.16 F cm−3) at 3 A/g and 82.1% capacitance retention after 10,000 cycles at 5A/g, in contrast to pure LIG (<100 F g−1). Moreover, the MnO2/LIG-based LIBs show the highest reversible discharge capacity of ∼1097 mAh g−1 at 0.2 A/g and ∼ 866.4 mAh g−1 at 1.0 A/g. This study opens a new route for synthesizing novel LIG-based composites from natural minerals.

Rational design and synthesis of bifunctional Dibenzo[g,p]chrysene-based conjugated microporous polymers for energy storage and visible light-driven photocatalytic hydrogen evolution

The importance of conjugated microporous polymers (CMPs) as active components in photocatalytic hydrogen evolution is growing due to its intense ultraviolet–visible (UV–vis) absorption, potent fluorescence, and high carrier transport capacity, dibenzo[g,p]chrysene shows notable photophysical and electrical features. This is because CMPs have stiff molecular structures with large π-conjugation. In this section, we describe our approach and syntheses of three types of polymers for the first time to determine the reactivity of dibenzo[g,p]chrysene (TBN)-based CMPs for photocatalytic H2 evolution and energy storage applications. Three TBN-based CMPs, TBN-TBN (D-D), TBN-TBN-TPA (A-D), and TBN-TBN-BT (D-A), were synthesized via Sonogashira–Hagihara coupling. TBN-CMP materials were used as working electrodes for energy storage applications. The TBN-TBN-BT CMP demonstrated excellent capacity retention (98.2%) over 2000 cycles and high capacitor (130 F g−1) at 0.5 A g−1, in accordance with electrochemical performance. Furthermore, the hydrogen evolution rate (HER) results are in the following order 8452, 9800, and 3060 μmol g−1h−1 for TBN-TBN, TBN-TBN-TPA, and TBN-TBN-BT CMPs, respectively. These findings suggest that using TBN as an acceptor increases the number of active sites for proton reduction, thereby boosting the rate of H2 evolution.

Biomass nanoarchitectonics with Annona reticulate flowers for mesoporous carbon impregnated on CeO2 nanogranular electrode for energy storage application

Metal oxide semiconductors with mesoporous nanoarchitecture are interesting new materials because they have more active sites and a substantially higher surface area, which makes them useful for a wide range of applications. Herein, we report the mesoporous carbon impregnated on CeO2 nanogranular using a pyrolysis method followed by a coprecipitation method. The ecological and affordable biowaste precursor, Annona reticulate flower, was used to prepare the mesoporous carbon. The effect of porous carbon in CeO2 nanogranular on the electrochemical properties of the mesoporous carbon impregnated on the CeO2 nanogranular electrode has been studied meticulously. A CeO2 electrode showed a specific capacitance of 332.9 F g-1 at 2 mA cm-2 current density and an excellent rate capability of 88.23 %. Then mesoporous carbon reveals a specific capacitance of 573.6 F g-1 at 2 mA cm-2 current density and an excellent rate capability of 92.10 %. Furthermore, the composition of mesoporous carbon and CeO2 electrodes showed an enhancement in the supercapacitor behavior. It showed a high specific capacitance of 753.2 % Fg-1 at 2 mA cm-2 current density and an excellent rate capability of 95.50 %. It is observed that the specific capacitance of the composite electrode is higher than that of the individual electrode because the specific area and porosity of the composite electrode are increased, which helps to adsorb more electrolytes and increase the supercapacitor’s behavior. The findings show that composite electrodes made from mesoporous carbon generated from waste biomass and nanogranular CeO2 can be significant electrode materials for energy storage applications.

Interfacial Structural and Dynamical Properties of [BMI+] [PF6 -] Ionic Liquids on the MXene Electrode: A Molecular Dynamics Simulation Study

Two-dimensional MXene nanomaterials are attracting more and more research interests as electrodes in energy storage applications. In this work, the interfacial structural and dynamical properties of solvent-free ionic liquids ([BMI+] [PF6 -]) on the MXene electrode are investigated using molecular dynamics simulation. Multiple alternating structures of [BMI+] cation and [PF6 -] anions on the MXene surface are observed. Interestingly, the ion diffusion coefficients are remarkably reduced (by 30~40%) in the interfacial Helmholtz layer. Importantly, an asymmetric bell-shaped differential capacitance profile with a maximum capacitance of ~7.04 μF/cm2 is observed. This is chiefly correlated with the structural properties of counterions rather than coins in the interfacial areas.

Influence of Fe Doping on the Electrochemical Performance of a ZnO-Nanostructure-Based Electrode for Supercapacitors.

ZnO is a potential candidate for providing an economic and environmentally friendly substitute for energy storage materials. Therefore, in this work, Fe-doped ZnO nanostructures prepared using the microwave irradiation procedure were investigated for structural, morphological, magnetic, electronic structural, specific surface area and electrochemical properties to be used as electrodes for supercapacitors. The X-ray diffraction, high-resolution transmission electron microscopy images, and selective-area electron diffraction pattern indicated that the nanocrystalline structures of Fe-doped ZnO were found to possess a hexagonal wurtzite structure. The effect of Fe doping in the ZnO matrix was observed on the lattice parameters, which were found to increase with the dopant concentration. Rods and a nanosheet-like morphology were observed via FESEM images. The ferromagnetic nature of samples is associated with the presence of bound magnetic polarons. The enhancement of saturation magnetization was observed due to Fe doping up to 3% in correspondence with the increase in the number of bound magnetic polarons with an Fe content of up to 3%. This behavior is observed as a result of the change in the oxidation state from +2 to +3, which was a consequence of Fe doping ranging from 3% to 5%. The electrode performance of Fe-doped ZnO nanostructures was studied using electrochemical measurements. The cyclic voltammetry (CV) results inferred that the specific capacitance increased with Fe doping and displayed a high specific capacitance of 286 F·g-1 at 10 mV/s for 3% Fe-doped ZnO nanostructures and decreased beyond that. Furthermore, the stability of the Zn0.97Fe0.03O electrode, which was examined by performing 2000 cycles, showed excellent cyclic stability (85.0% of value retained up to 2000 cycles) with the highest specific capacitance of 276.4 F·g-1, signifying its appropriateness as an electrode for energy storage applications.

Double redox-active quinone molecules functionalized a three-dimensional graphene network for high-performance supercapacitor

As a well-known two-dimensional material, graphene is widely used as an electrode material in energy storage devices. However, the tendency of the agglomeration or restacking of graphene sheets limit the properties. To overcome this issue, redox-active molecules can be introduced that inhibit the stacking of graphene sheets and impart excellent pseudocapacitance properties. In this study, we design a three-dimensional (3D) graphene network anchored with redox-active 2,5-(di-p-phenylenediamine)-1,4-benzoquinone (DBP) and hydroquinone (HQ) (DFGN) using a facile one-step hydrothermal process. The covalent binding and absorption between redox-active molecules and graphene sheets reduce restacking and enable promising pseudocapacitance through reversible faradic reactions of quinone and aniline structures. Among all the samples, DFGN-1 shows the best specific capacitance (667.3 F/g at 1 A/g), high-rate capability (89.2 % even up to 50 A/g), and good cycling stability. Furthermore, DFGN-1 is also employed as an electrode material to construct flexible solid-state supercapacitors (FSSCs), which exhibit great specific capacitance (441 F/g at 0.5 A/g), excellent cycling stability (90.6 % after 10,000 cycles at 10 A/g) and high-energy density of 9.29 Wh/kg at a power density of 96.22 W/kg. Interestingly, FSSCs also display great mechanical flexibility in bending and twisting states and extraordinary mechanical durability even after being bent 5000 times. Overall, double redox-active quinone molecules functionalized 3D graphene network provides a novel tactic to construct promising potential electrodes in energy storage applications.

Bifunctional strontium-doped barium oxide nanorods as promising photocatalysts and electrodes for energy storage applications

It is critical to design highly efficient, clean, and renewable energy sources to replace fossil fuels and mitigate their harmful impacts on the environment. Two effective approaches for replacing fossil fuels are electrochemical energy storage devices and photocatalysis. Herein, for the first time, strontium-doped barium oxide nanorods (Sr-BaO NRs) were synthesized using a facile co-precipitation technique and characterized with different analytical techniques to explore their physical, electrochemical, and photocatalytic properties. The successful formation of Sr-BaO NRs and their structural variations were confirmed by XRD, Raman, and FT-IR results. UV–Vis analysis showed that the bandgap of BaO was decreased by increasing the Sr concentration. SEM micrographs confirmed the formation of nanorods. The findings of the photocatalytic experiments showed excellent photodegradation efficiencies against methylene blue (MB) (95.55 %), methyl orange (MO) (98 %), and rhodamine-B (RhB) (96.33 %) dyes after 60, 70, and 90 min, respectively under UV light irradiation. Higher stability up to five cycles was shown in the recyclability experiments employing the optimized catalyst. The electrochemical properties of Sr-BaO NRs were also studied for the first time. 4 % Sr-BaO NRs offered an exceptional specific capacitance of 925.2 F/g, and a good energy density of 32.12 Wh/Kg with a higher power density of 750 W/kg at a current density of 3 A/g. The development of such affordable and efficient photocatalysts and electrode materials is desired for future environment protection and energy storage applications.

Easily accessible and tunable porous organic polymer anode from azo coupling for sustainable lithium-organic batteries

Porous organic polymers (POPs) are promising sustainable electrodes for energy storage applications. Although a handful of POPs with facile synthesis and structural tunability have been developed, they are limited to specific classes of precursors and transition metal-based catalysts. In this work, three tunable porous organic polymers were successfully synthesized and characterized using the simple azo coupling reaction of readily available precursors, phloroglucinol, and diarylamines. The α-hydrazoketone was unambiguously assigned based on X-ray photoelectron spectroscopy (XPS). The POPs with a redox-active functional group deliver impressive reversible capacity. The effects of POP precursors, surface area, and pore size on the electrochemical properties and battery performances were systematically investigated. According to the results, a high content of α-hydrazoketone and a large surface area are critical factors in designing efficient organic electrodes for high-performance energy storage. Interestingly, POP-1 derived from o-tolidine precursor exhibited a high specific capacity with greater rate capability as well as superior cycling stability over 1,000 cycles due to the importance of the magic methyl effect, optimal surface area (294 m2 g−1), and porosity. Furthermore, ex-situ FT-IR, Raman, and XPS studies also implicate the reversible redox reaction of α-hydrazoketone. Cyclic voltammetry and electrochemical impedance spectroscopy revealed kinetic behavior influencing the lithium-ion storage mechanism. This research provides empirical evidence that this tunable family of porous organic polymers is the first to exhibit promising organic electrode characteristics for the next generation of sustainable lithium-organic batteries.

Enhanced Interfacial Magnetization is Responsible for the Negative Capacity Fading of Cobalt Ditelluride Anodes for Lithium Storage.

In lithium-ion batteries (LIBs), the stabilized capacities of transition metal compound anodes usually exhibit higher values than their theoretical values due to the interfacial charge storage, the formation of reversible electrolyte-derived surface layer, or interfacial magnetization. But the effectively utilizing the mechanisms to achieve novel anodes is rarely explored. Herein, a novel nanosized cobalt ditelluride (CoTe2 ) anodes with ultra-high capacity and long term stability is reported. Electrochemical tests show that the lithium storage capacity of the best sample reaches 1194.7mA h g-1 after 150 cycles at 0.12 A g-1 , which increases by 57.8% compared to that after 20 cycles. In addition, the sample offers capacities of 546.6 and 492.1mA h g-1 at 0.6 and 1.8 A g-1 , respectively. During cycles, CoTe2 particles (average size 20nm) are gradually pulverized into the smaller nanoparticles (<3nm), making the magnetization more fully due to the larger contact area of Co/Li2 Te interface, yielding an increased capacity. The negative capacity fading is observed, and verified by ex situ structural characterizations and in situ electrochemical measurements. The proposed strategy can be further extended to obtain other high-performance ferromagnetic metal based electrodes for energy storage applications.