Charge Discharge Experiments Research Articles

Polyoxometalate/α-Fe2O3/polyaniline composite: Tailored approaches for high-performance supercapacitors

The need for portable, high-performance electronics that have high power or energy density has increased significantly in recent years. In this work, a composite material was coated on stainless steel that consists of polyoxometalate (POM)/α-Fe2O3/polyaniline (PANI) as an electrode material for a symmetric supercapacitor. α-Fe2O3 was prepared using starch as a template while PANI was electrodeposited. The physical and chemical characteristics of the modified electrodes were investigated via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic chargedischarge (GCD) experiments. In 1 M H2SO4, the composite had a specific capacitance of 528 F/g at a current density of 0.2 A/g. In addition, the composite exhibited a high energy density of 73.4 Wh kg−1 at a high-power density of 7.14 kW kg−1 and 91.62 % capacity retention after 10 cycles. The results show that POM/α-Fe2O3/PANI is a promising composite electrode for use as a supercapacitor electrode material.

Thermal Performance of a Cylindrical Li[Ni0.6Co0.2Mn0.2]O2/Graphite Battery based on the Electrochemical-Thermal Coupling Model

The thermal safety of lithium-ion batteries has garnered significant attention due to its pivotal role in the field of new energy. In this work, a three-dimensional electrochemical-thermal coupling model based on the P2D model was established for predicting the thermal performance. The charge-discharge and temperature rise experiments via 18650 cylindrical Li[Ni0.6Co0.2Mn0.2]O2 / graphite batteries are designed to confirm the rationality of the model. The simulation results show that the highest temperature of the battery surface during discharging at 1 C and 4 C are 42.85 °C and 61.25 °C, and the experimental results are 42.50 °C and 62.85 °C, respectively. The electrode heat generation mainly comes from the reaction heat of cathode and anode during 1 C charge process, the maximum power is 1.2 W and 0.6 W, respectively. In the discharge process, the cathode dominates the reaction contribution of 1.02 W and the reaction heat power from the anode is only 0.016 W. The capacity of heat dissipation can be increased by enhancing the convective heat transfer coefficient and air velocity within a reasonable range. The proposed electrochemical-thermal coupling model is valuable to evaluate the heat behavior and promote the battery development.

A hybrid battery degradation model combining arrhenius equation and neural network for capacity prediction under time-varying operating conditions

Capacity degradation modeling and remaining useful life (RUL) prediction play a pivotal role in enhancing the safety of battery energy storage systems. Lithium-ion batteries utilized in the systems are subjected to intricate and variable operating conditions, including temperature, charging/discharging rates and depth, which result in time-varying degradation rates. However, most existing models for battery capacity prediction have the limitation of ignoring the quantitative effects of time-varying operating conditions on degradation. Therefore, a hybrid battery capacity degradation model combining Arrhenius equation and lightweight Transformer is constructed. The effects of operating conditions on capacity degradation rates are introduced by an improved Arrhenius degradation equation. The coordinate ascent method embedded with Newton descent is used for estimating the model parameters. Then, the unknown mapping relationships between the degradation statistical features extracted from monitoring data and the degradation factors are captured by the light-weight Transformer. Finally, a novel framework consisting of future capacity and RUL predicting is constructed based on sequential importance resampling (SIR). For the purpose of verification, the cyclic charge-discharge experiments of eight battery cells under two distinct operating profiles are designed and conducted. Compared with other models, the proposed model achieves the best prognostics performance on the tested cells.

A Novel Synthesis of ZnNb2O6 Nanoparticles via Combustion Method: Supercapacitor and Photocatalytic Properties

AbstractIn light of the current study's demonstration of the synthesis of Zn doped niobium metal oxide a low‐cost approach is provided for the synthesis of ZnNb2O6 nanoparticles. Using the urea and oxalyl dihydrazide (ODH) as fuel and complexing agent, ZnNb2O6 NPs are synthesized via the solution combustion process. The X‐ray diffraction (XRD) patterns reveal that ZnNb2O6 has a columbite‐orthorhombic structure. The field emisssion‐scanning electron microscopy (FE‐SEM) micrographs revealed the presence of uniform and spherically shaped morphology for ZnNb2O6. The role of ZnNb2O6 in the photocatalytic degradation of fuchsin acid dye is investigated under UV‐rays. The remarkable photocatalytic degradation activity of the material is demonstrated with 90% degradation rate. The fabricated electrode is used for the electrochemical analysis of the resultant material. The capacitance of 223 and 198 Fg−1 at a scan rate of 5 Ag−1, respectively, are measured in a 3‐electrode using the chemically generated ZnNb2O6, as per the Galvanostatic charge discharge (GCD) experiment. Furthermore, it exhibited excellent cycling stability, maintaining over 85% of its initial capacitance even after 2000 cycles. The goal of this research is to develop a solution combustion method for synthesizing ZnNb2O6 NPs from urea and ODH so that it may be more effectively tested for electrochemical, sensing, and photocatalytic uses.

Nitrogen-Doped Carbon Nanothin Film as a Buffer Layer between Anodic Graphite and Solid Electrolyte Interphase for Lithium-Ion Batteries.

Lithium-ion batteries are essential batteries for electric vehicle drive systems. Such batteries must provide stable performance over a long period of time. Therefore, the degradation or aging of the battery capacity must be improved. In the case of the current graphite anodes, graphite coated with an amorphous layer is used. It is known that the amorphous layer can reduce the irreversible capacity loss caused by the solid electrolyte interphase (SEI) layer. The amorphous carbon layers reduce the initial capacity due to higher electrical resistance. In this study, we aim to develop a buffer layer using nitrogen-containing graphene that would prevent the increase in electrical resistance while maintaining the amorphous structure. Coatings with different film thicknesses were prepared by using the solution plasma method. The thinnest sample was oven sintered to optimize the structure, especially the surface and interface of the layer. The battery capacity from charge-discharge experiments and the resistance change of each part from electrochemical impedance measurements were evaluated. The results showed that the coating layer increased the electrical resistance of the graphite anode. On the other hand, the resistance of the SEI layer was reduced by the coating layer. It can be predicted that the addition of the coating layer will increase the total charge transfer resistance (R ct) of the cell but will also improve the period average capacity in the long run. To be used as a practical material, the film thickness would need to be further reduced, and the balance between the loss of charge transfer resistance and the gain of SEI layer resistance would need to be further optimized.

Exploring the Potential of Nitrogen-Doped Graphene in ZnSe-TiO2 Composite Materials for Supercapacitor Electrode.

The current study explores the prospective of a nitrogen-doped graphene (NG) incorporated into ZnSe-TiO2 composites via hydrothermal method for supercapacitor electrodes. Structural, morphological, and electronic characterizations are conducted using XRD, SEM, Raman, and UV analyses. The electrochemical study is performed and galvanostatic charge-discharge (GCD) and cyclic voltammetry (CV) are evaluated for the supercapacitor electrode material. Results demonstrate improved performance in the ZnSe-NG-TiO2 composite, indicating its potential for advanced supercapacitors with enhanced efficiency, stability, and power density. Specific capacity calculations and galvanic charge-discharge experiments confirmed the promising electrochemical activity of ZnSe-NG-TiO2, which has a specific capacity of 222 C/g. The negative link among specific capacity and current density demonstrated the composite's potential for high energy density and high-power density electrochemical devices. Overall, the study shows that composite materials derived from multiple families can synergistically improve electrode characteristics for advanced energy storage applications.

Ethylenediamine-functionalized metal-organic frameworks for applications of electrochemical supercapacitors as an additive

In this study, the impact of incorporating ethylenediamine (ED)-functionalized metal-organic frameworks (MOFs) on enhancing the electrochemical performance of polypyrrole(PPy)-based conducting polymers as supercapacitor electrode materials was investigated. The stability of terephthalic acid-containing MOFs in different environments, including exposure to acids, relies on the specific metal ions and ligands utilized in their construction. In this research, ED treatment was chosen for its resistance to acid attack. Unlike the post-synthetic modifications observed in previous literature regarding ED-modified MOF5, this study introduces a unique approach where ED is directly integrated into the framework in a single step. The resulting materials, referred to as ED-MOF, were employed in creating a novel composite material concurrently with polypyrrole, designed for use as electrode materials in supercapacitor applications. The optimal loading in the electrochemical preparation of polypyrrole-based conducting polymers was determined using cyclic voltammetry and electrochemical impedance spectroscopy techniques. Areal capacitance for the resulting electrodes was evaluated through cyclic charge-discharge experiments. The areal capacitance of the ED-ZnMOF/1@/PPy/PGE electrode was found to be 575.2 mF.cm−2 at a charge/discharge current density of 1 mA.cm−2. This research underscores the potential advantages of combining conducting polymers and metal-organic frameworks in supercapacitors, as well as other electrochemical systems.

Influence of sintering temperature on the electrical properties of SrTiO3–BaZrTiO3 ceramics for energy storage applications

The impact of the sintering temperature on the phase composition and electrical properties of 5%SrTiO3–95%BaZr0.15Ti0.85O3 (ST-BZT) ceramics fabricated by solid-state method and consolidated by two-step sintering is presented. A systematic analysis of the phase composition, microstructures, dielectric, ferroelectric, and energy storage characteristics. A di-phase SrTiO3–BaZrTiO3 composite is obtained at low sintering temperatures below 1400 °C. Increasing the sintering temperature causes a shift of the Curie temperature from 62 °C to 55 °C together with changes of permittivity values and of the ferroelectric loops, thus indicating a progressive interdiffusion process at the interfaces, together with a better densification. Remarkably, the ST-BZT composition sintered at 1500 °C exhibits characteristics of a single phase (Ba,Sr) (Zr,Ti)O3 solid solution, with high room temperature permittivity around 2950 and good ferroelectric response (saturation polarization Pmax = 12.6 μC/cm2 and remnant polarization Pr = 2.16 μC/cm2). Consequently, this composition displays a much greater recoverable energy density (Wrec = 54.5 mJ/cm3) in comparison to the ones of the di-phase ST-BZT composites and the parent phases. However, the (Sr0.05Ba0.95) (Zr0.14Ti0.86)O3 solid solution, demonstrates a lower energy efficiency (72%) in comparison to the ST-BZT di-phase composites sintered at lower temperatures, which exhibit higher energy efficiency values around 86%. In addition, the charge-discharge experiments were performed under different electric fields to disclose the difference in energy storage properties in 5%SrTiO3–95%BaZr0.15Ti0.85O3 ceramics. This suggests that the sintering strategy plays a crucial role in determining the energy efficiency of the obtained ceramics. Additionally, all the investigated ST-BZT ceramics present high energy efficiency at low-applied electric fields, suggesting their potential as candidates for energy storage capacitors operating at moderate fields.

Synergy of zero-dimensional carbon dots decoration on the one-dimensional architecture of Ag-doped V2O5 for supercapacitor and overall water-splitting applications

The production of renewable energy sources and energy storage devices is crucial in addressing current global energy challenges. Hydrogen energy is a clean form of energy that can be produced without any harmful by-products. For this purpose, nanorods of vanadium oxide (V2O5) and silver-doped vanadium oxide (Ag/V2O5) were synthesized by hydrothermal route. The carbon dots decorated silver doped vanadium oxide (Ag/V2O5@C) was fabricated using an ultrasonication approach. Various physio-chemical techniques were used to characterize the fabricated samples. The synthesized materials were employed as electrodes and electrocatalysts for supercapacitor and water-splitting applications. Cyclic voltammetry and cyclic charge–discharge experiments were performed, and results showed that Ag/V2O5@C exhibited 936 Fg−1 specific capacitance at 5 mVs−1 and 977 s discharge time. The charge transfer resistance was calculated via electrochemical impedance spectroscopy and Ag/V2O5@C showed a lower charge transfer resistance than other prepared materials. At 10 mAcm−2, Ag/V2O5@C exhibited lower overpotential of 126 mV and 388 mV for hydrogen evolution (HER) and oxygen evolution reactions (OER) respectively. The lower tafel slope of 81 mV dec−1 and 71 mV dec−1 was attributed to the Ag/V2O5@C for HER and OER respectively. Ag/V2O5@C showed higher reaction kinetics due to the fast rate of charge transfer, low resistance, high conductivity, and greater active sites provided by the carbon dots for electrocatalytic reaction. So, Ag/V2O5@C can be employed as an effective electrocatalyst and electrode material for electrochemical applications.

Improved solubility of titanium-doped polyoxovanadate charge carriers for symmetric non-aqueous redox flow batteries.

Non-aqueous redox flow batteries constitute a promising solution for grid-scale energy storage due to the ability to achieve larger cell voltages than can be readily accessed in water. However, their widespread application is limited by low solubility of the electroactive species in organic solvents. In this work, we demonstrate that organic functionalization of titanium-substituted polyoxovanadate-alkoxide clusters increases the solubility of these assemblies over that of their homoleptic congeners by a factor of >10 in acetonitrile. Cyclic voltammetry, chronoamperometry, and charge-discharge cycling experiments are reported, assessing the electrochemical properties of these clusters relevant to their ability to serve as multielectron charge carriers for energy storage. The kinetic implications of ligand variation are assessed, demonstrating the role of ligand structure on the diffusivity and heterogeneous rates of electron transfer in mixed-metal charge carriers. Our results offer new insights into the impact of structural modifications on the physicochemical properties of these assemblies.

Gel Polymer Electrolytes for Flexible LiXPO4 (X=Mn,Fe,Co)-Fractal-like Fe2O3 Hybrid Supercapacitor Devices

In the recent years, the development of electrochemical energy storage device has been widely investigated. Supercapacitors are known for their excellent power density and superb cycling stability but restricted by low charge storage capacity, on the other hand batteries provide high energy density, limited by low power density. Here, olivine-structured LiXPO4 (X=Mn,Fe,Co) possessing high energy storage capability is used as a positive electrode. Our recent research demonstrated that Fe2O3-based Fractal-like structures supported on Ni Foam exhibit extremely high specific capacitance of ~2708 F g-1 at 1 A g-1 in 1 M KOH electrolyte, when used as negative electrode [1]. Hence, the Fractal-like Fe2O3 is used as the negative electrode for the envisaged hybrid supercapacitor device. The flexibility is imparted to these devices by employing carbon cloth as the current collector. The choice of suitable electrolyte is crucial for supercapacitor applications as it decides the working potential window, electrode-electrolyte interaction, and ionic conductivity. Here, PVA based gel polymer electrolyte (GPE) is used due to the ease in gel formation and non-toxicity to make flexible hybrid supercapacitor device. Different PVA based GPEs are synthesized using H3PO4, H2SO4 and KOH with Ionic liquids viz. EMIMBF4 and EMIMCl. The role of GPEs in the performance of LiXPO4 (X=Mn,Fe,Co)//GPE//Fe2O3 hybrid supercapacitors is understood through charge storage mechanisms deciphered from galvanostatic charge-discharge (GCD) experiments, Electrochemical Impedance Spectroscopy (EIS).

Effect of reducing agents on structural, morphological, optical and electrochemical properties of Mn2O3 nanoparticles by co-precipitation method

Abstract In this work, two different reducing agents namely sodium hydroxide and potassium hydroxide (NaOH and KMnO4) were used to synthesis of manganese oxide (Mn2O3) nanoparticles by the co-precipitation method and examined for the electrochemical applications. The as-prepared Mn2O3 nanoparticles using NaOH precursor, dried in a hot oven at 80 °C for 6 h (MN-1) and then annealed for 7 h at 600 °C (MN-2). Similarly, Mn2O3 nanoparticles were prepared using KMnO4 precursor, dried in a hot oven at 80 °C for 6 h (MK-1) and then annealed for 7 h at 450 °C (MK-2), respectively. The influences of reducing agents on structural, morphological and optical properties were investigated. The structural analysis revealed the prepared samples had tetragonal crystal structures with better crystallinity. FT-IR spectral analysis revealed the characteristic bonds of Mn–O–Mn were observed in the region of 486–573 cm−1. The FE-SEM and HR-TEM images showed coral-like and nanorod structures for samples MN-2 and MK-2, with exhibited lattice value of 0.27 nm related to the (222) plane. The presence of the elements manganese (Mn) and oxygen (O) was confirmed by EDAX mapping. The XPS study confirmed that the oxidation state of the prepared samples was +2. The UV-Vis spectra suggested that the adsorption edge was blue-shifted compared to the sample MN-2. Cyclic voltammetry (CV) and galvanostatic charge–discharge experiments demonstrated that charge storage in Mn2O3 exhibited faradic-dominated capacitive behavior. MN-2 nanorod structures were obtained at excellent specific capacitance value of 196 F g−1 compared to MK-2 nanoparticles. Based on this study, Mn2O3 nanoparticles was recommended as exceptional electrode materials for efficient supercapacitor applications due to its superior electrical conductivity, large surface area and redox properties.

Charge storage capacity of electromethanogenic biocathodes

Methanogenic biocathodes (MB) can convert CO2 and electricity into methane. This feature, that allows them to potentially be used for long-term electrical energy storage, has aroused great interest during the past 10 years. MB can also operate as biological supercapacitors, a characteristic that can be exploited for short-term energy storage and that has received much less attention. In this study, we investigate the electrical charge storage capabilities of carbon-felt-based MB modified with graphene oxide. The charge-discharge experiments revealed that the potential of the electrode plays an important role during the discharging period: low potentials (−1.2 V vs Ag/AgCl) created an inrush of faradaic current that masked any capacitive current. At more positive potentials (−0.8 V vs Ag/AgCl), the biological electrodes were outperformed by the abiotic electrodes, and only when the potential was set at −1.0 V vs Ag/AgCl the graphene-modified biological electrode showed its superior charge storage capacity. Overall, results indicated that the graphene modification is crucial to obtain bioelectrodes with improved capacitance: untreated bioelectrodes showed a charge storage capacity inferior to that measured in the abiotic electrodes.

Post-mortem analysis of the Li-ion battery with charge/discharge deterioration in high- and low-temperature environments

Li-ion batteries have widespread applications. However, their deterioration mechanisms at different temperature conditions remain unclear. In this study, we investigate the effect of high- and low-temperature environments on the charge–discharge performance of an 18650 Li-ion battery having a Li(Ni,Co,Al)O2-family cathode and a graphite anode. After 50 cycles under three temperature conditions, the surfaces of the cathode and anode removed from the disassembled batteries are analyzed using scanning electron microscopy. The crystal and electronic structures of the cathode and anode materials are investigated using X-ray diffraction and X-ray absorption spectroscopy. The anode after 50 cycles at 5 °C is also investigated using X-ray photoemission spectroscopy. Results of the charge–discharge experiments indicate that, under identical charge–discharge conditions, the deterioration in the battery performance at a low-temperature environment of 5 °C is greater than that at environments of 25 and 80 °C. The post-mortem analyses of the cathode and anode samples of the battery cycled at 5 °C reveal the primary reasons for the decrease in battery capacity. The generation of deposits, including metallic Li, Li2CO3, and LiF, on the anode surface is clarified. During this process, the Li ions available for reinsertion into the cathode decrease. Furthermore, the Ni3+ component is partly reduced to Ni2+ near the surface of the cathode active material, and the reactive oxygen species are generated simultaneously. The reactive oxygen species can promote Li deficiency and surface-electrolyte interface formation. The above understanding of the deterioration mechanism can contribute to developing safer battery usage methods.

Candle soot-metal-organic framework-based hierarchical electrode as high-performance anode for Li-ion batteries

Recently, cobalt oxide-based materials have been considered high-performance anode materials. However, cobalt oxide materials display drawbacks such as capacity fade, poor cycle life, and substantial structural strain. In this work, we report a facile synthesis of carbon-cobalt oxide composite to improve the electrode's storage capabilities and cycle life. First, metal–organic framework-based cobalt oxide nano leaves are synthesized by simple coprecipitation followed by calcination. After that, candle soot-derived carbon nanoparticles are uniformly deposited on the cobalt oxide nano leaves by a simple flame synthesis method to form a composite electrode. The fractal-like interconnected carbon nanoparticles improve the electron conducting pathways. In contrast, metal–organic framework-derived porous cobalt oxide nano leaves enhance energy storage abilities through reversible conversion reactions. The superior performance of the composite electrode is established from the galvanostatic charge–discharge experiments. Also, the composite electrode has delivered outstanding specific capacities of 811 and 503 mAh g−1 at 50 and 1000 mA g−1 current densities, respectively. Furthermore, the composite electrode exhibited good cyclic stability at 1000 mA g−1 current density by delivering an excellent specific charge capacity of 490 mAh g−1 even after 400 cycles. Therefore, these superior electrochemical properties confirm the potential applicability in high-performance and stable Li-ion batteries.

Influence of annealing on the morphological, structural and electrochemical properties of Co3O4 spinel electrodes

Effectual use of energy requires the conversion and storage device with great ability. In this research, Co3O4 nanoparticles are achieved via facile and low-cost reflux method. The consequence of annealing treatment on morphological, structural, and electrochemical behaviors of produced Co3O4 (350, 550, 750 and 950 °C) nanoparticles are investigated. XRD analysis exposes the formation of cubic Co3O4 spinel above 300 °C annealing temperature. SEM and EDX study demonstrate that the morphology of Co3O4 nanoparticles changes with different annealing temperatures. The electrochemical performance of prepared Co3O4 (350–950 °C) nanoparticles was determined via charge-discharge experiment, and electrochemical impedance, cyclic voltammetry studies. It exposes that the annealing treatments have an important effect on the specific capacitances. Among them, the optimized Co3O4 (950 °C) electrode demonstrates the best capacitive behaviors in the three-electrode cell, which exhibitions the best capacitance value of 1388 Fg−1 at 5 mVs−1 and outstanding cycling capability of 97.2 % capacitance even after 5000 cycles. The asymmetric supercapacitor device assembled by Co3O4 (950 °C) displays a capacitance value of 519.3 Fg−1 for 5 mVs−1 and long reversible capacity (92.7 % capacitance retains after 5000 cycles) and a high-power density (26.7 W h Kg−1). These outcomes exposed that the Co3O4 (950 °C) nanoparticles could be a perfect candidate for eminent electrochemical application as electrode materials. These results state that Co3O4 nanoparticles are a multipurpose material and thus can be applied in numerous applications namely gas sensors, fuel cells, solar cells, electrochemical sensors, and photocatalysis.

Carbon-cement supercapacitors as a scalable bulk energy storage solution.

The large-scale implementation of renewable energy systems necessitates the development of energy storage solutions to effectively manage imbalances between energy supply and demand. Herein, we investigate such a scalable material solution for energy storage in supercapacitors constructed from readily available material precursors that can be locally sourced from virtually anywhere on the planet, namely cement, water, and carbon black. We characterize our carbon-cement electrodes by combining correlative EDS-Raman spectroscopy with capacitance measurements derived from cyclic voltammetry and galvanostatic charge-discharge experiments using integer and fractional derivatives to correct for rate and current intensity effects. Texture analysis reveals that the hydration reactions of cement in the presence of carbon generate a fractal-like electron-conducting carbon network that permeates the load-bearing cement-based matrix. The energy storage capacity of this space-filling carbon black network of the high specific surface area accessible to charge storage is shown to be an intensive quantity, whereas the high-rate capability of the carbon-cement electrodes exhibits self-similarity due to the hydration porosity available for charge transport. This intensive and self-similar nature of energy storage and rate capability represents an opportunity for mass scaling from electrode to structural scales. The availability, versatility, and scalability of these carbon-cement supercapacitors opens a horizon for the design of multifunctional structures that leverage high energy storage capacity, high-rate charge/discharge capabilities, and structural strength for sustainable residential and industrial applications ranging from energy autarkic shelters and self-charging roads for electric vehicles, to intermittent energy storage for wind turbines and tidal power stations.

Electrochemical Studies of Inkjet Printed Semi-Transparent NiCo2O4/ITO Supercapacitor Electrodes

Transparent supercapacitors find a large number of applications as components of many electronic devices and circuits. Mixed Ni–Co oxides (NCOs) are among the most promising supercapacitor electrode materials exhibiting high pseudo-capacitance and good electronic conductivity, while inkjet printing is a low cost and versatile technique for electrode printing. Surprisingly, although there have been many studies of NCO supercapacitor films on ITO glass substrates, these have not been prepared by the inkjet technique, and their optical properties were not fully characterized. Hereby, we report the fabrication and characterization of thin (295 and 477 nm thick; 0.017 and 0.035 mg cm−2 NCO loading) semi-transparent NiCo2O4/ITO supercapacitor electrodes, showing transparency to visible light (60–30%, from the thinner to the thicker electrode layers tested), typical mass specific capacitance for NCO-based supercapacitor electrodes (1294–829 Fg−1 at 1 mA cm−2 discharge current density) and high volumetric capacitance (746–608 F cm−3 at 1 mA cm−2). The NCO nanoparticles were prepared by hydrothermal synthesis followed by thermal treatment and ball milling (ZrO2 balls, 0.5 mm diameter), resulting in a cubic nickel–cobalt oxide structure and particle size in the 30–150 nm range, whereas the electrode layers were printed from water-propylene glycol solutions using a Dimatix DMP-2850 drop-on-demand (DoD) inkjet printer. Constant current charge–discharge experiments of the supercapacitor electrode (at ca 0.5 mA cm−2) for 1000 cycles confirmed stability of performance.

A Scalable Method for Enhancing the Crystallinity of Zn Powder to Reduce Corrosion and Boost Achievable Capacity

Zinc corrosion is an unavoidable phenomenon in alkaline systems. Additives like surfactants and metals at the ppm level are typically included in the zinc-alkaline cell production process to help suppress corrosion. Though these inclusions have helped remediate the issue, the inclusions themselves bring forward new issues such as increased toxicity and cost. Therefore, a method for achieving reduced Zn corrosion that can either complement or replace additives is highly desirable. In this work, a method for the scalable improvement of zinc microparticle crystallinity, without the use of additives, is presented and detailed. The recrystallization process involves oxide film formation, thermal annealing, and oxide film removal. The process converts polycrystalline particles into either a single crystal or one with larger, fewer total grains while conserving particle shape and size. This paper demonstrates reduced corrosion and enhanced achievable capacity for the recrystallized particles as well as improved cyclability. More specifically, the recrystallized particles demonstrate a 19% reduction in corrosion current and a 12% increase in achievable capacity when probed by linear sweep voltammetry and constant current discharge, respectively. When cycled in charge-discharge experiments, the recrystallized particles boast up to a 114% improvement in cyclability.

SOC estimation of lithium battery based on multi-innovation unscented Kalman filter algorithm

Precise of the state is an imperative necessity for ensuring the dependable operation of lithium-ion batteries. The state of charge (SOC) of lithium-ion batteries is arduous to determine precisely. Therefore, a novel method was proposed, which incorporates the Unscented Kalman Filter (UKF) algorithm in combination with the theory of multi-innovation. This method exhibits an enhanced estimation precision of the UKF algorithm by means of re-utilizing prior information. The process encompasses a charge-discharge experiment, and identification of offline parameters for obtaining the RC equivalent-circuit model parameter. The model was verified to be accurate and correct through simulation using Matlab/Simulink. The UKF and MIUKF methods are utilized for estimating the actual operational state of a single lithium battery. According to experimental results, MIUKF offers a higher degree of accuracy and effectiveness in estimating the SOC than the UKF algorithm, with a smaller margin of SOC estimation error.