Showing papers in "Journal of Solid State Electrochemistry in 2019"
TL;DR: In this article, a review presents applications of different forms of elemental carbon in lead-acid batteries, including reticulated current collectors for both negative and positive plates, as well as carbon nanostructures and composite materials can also play a role.
Abstract: A review presents applications of different forms of elemental carbon in lead-acid batteries. Carbon materials are widely used as an additive to the negative active mass, as they improve the cycle life and charge acceptance of batteries, especially in high-rate partial state of charge (HRPSoC) conditions, which are relevant to hybrid and electric vehicles. Carbon nanostructures and composite materials can also play such a role. The positive active mass additions are generally less beneficial than the negative ones. Carbon can also be applied as a material for reticulated current collectors for both negative and positive plates. This modern technology allows to increase the battery specific energy and active mass utilization. Batteries with such collectors can show improved cycle life, owing to a better active mass mechanical support. Other recent use of carbon in secondary batteries is as supercapacitor electrodes. They can replace the negative plate or be connected in parallel with such a lead plate. These solutions increase the specific power and HRPSoC performance. Presented new carbon-based technologies in a construction of lead-acid batteries can significantly improve their performance and allow a further successful competition with other battery systems.
66 citations
TL;DR: In this article, a uniform MgO coating was applied on LiNi0.8Co0.1Mn 0.1O2 (NCM811) cathode material for electric vehicles.
Abstract: LiNi0.8Co0.1Mn0.1O2 (NCM811) has a high potential for using as the cathode material for lithium–ion batteries (LIBs) for electric vehicles owing to its high energy density and low cost. However, its poor rate capability and cycling performance have significantly hindered its application. In this study, we successfully design a uniform magnesium oxide (MgO) coating on NCM811 via a wet-chemical coating followed by heat treatment using magnesium ethoxide [Mg (OEt)2] dissolved in ethanol as the Mg source. The effects of MgO coating on the surface states, crystal structure, and electrochemical performances of NCM811 cathode material are studied in detail. After 100 cycles, the capacity retention of MgO-coated NCM811 is 90.1% at room temperature at 1 C, whereas the pristine NCM811 is only 74.5%. Besides, the MgO-coated NCM811 delivers a better rate property than pristine NCM811. Prominent improvements in electrochemical performances are attributed to the fact that the formation of MgO coating layer helps to suppress deleterious side reactions, lower the overpotential on the surface, and facilitate lithium–ion diffusion.
54 citations
TL;DR: An overview of different types of supercapacitors (electrical double-layer capacitors (EDLCs), pseudocapacitors and hybrid supercapACitors) can be found in this paper.
Abstract: Supercapacitors means electrochemical capacitors are being considered these days to be a good alternative for the conventional power sources (fuel cells and batteries) in many applications because of their high power density, long cycle life and less charging and discharging time. This review article presents an overview of different types of supercapacitors (electrical double-layer capacitors (EDLCs), pseudocapacitors and hybrid supercapacitors. The device configurations (symmetric, asymmetric and hybrid), the mechanism of charge storing at the surface (ion adsorption for EDLCs and fast surface redox reactions for pseudocapacitors) and the effect of electrode material (activated carbon, carbon aerogels, carbon fabrics, carbide-derived carbons, carbon nanotubes (CNTs), graphene, biomass, etc. for EDLCs and conducting polymers and insertion type compounds for pseudocapacitors) and electrolytes are crucial. Electrolytes used in the supercapacitors also play important role to determine its operating voltage range, energy density, power density, etc. Both the classes of electrolytes, liquid electrolytes (aqueous, organic, ionic liquids) and solid electrolytes (polymer-based electrolytes) are also discussed in the last section of this review. The voltage range, energy density and power density ultimately define their use for different applications namely heavy electric vehicles and portable electronic devices.
52 citations
TL;DR: In this paper, a modified carbon paste electrode with Sn(II)-exchanged clinoptilolite nanoparticles (CNP-Sn(I)-CPE) showed voltammetric current (in cyclic voltammetry (CV)) for Sn (II)/Sn(IV) in sulfuric acid electrolyte (pH 2), the peak current was decreased when bromate was added to the solution.
Abstract: A modified carbon paste electrode with Sn(II)-exchanged clinoptilolite nanoparticles (CNP-Sn(II)-CPE) showed voltammetric current (in cyclic voltammetry (CV)) for Sn(II)/Sn(IV) in sulfuric acid electrolyte (pH 2). The peak current was decreased when bromate was added to the solution. Hence, this decrease was used for indirect voltammetric determination of bromate. In designed experiments using response surface methodology (RSM) approach in square-wave voltammetry (SqW), strong acidic pH values (pH 1.8–2.5) caused an increased SqW voltammetric response, because such pH values bring sufficient Sn(II) as the electroactive species at the electrode surface via ion-exchange process. The optimal variables obtained are sulfuric acid as supporting electrolyte at pH 1.80, modifier% at 25, amplitude at 498.4 mV, step potential at 5.4 mV, and frequency at 25 Hz. The peak current of Sn(II)/Sn(IV) redox pair was inversely proportionate to the concentration of bromate. Hence, ΔI (difference in peak current in the absence and presence of bromate) was proportionally increased with increasing the concentration of bromate in the range of 5.00 to 100.00 μmol L−1 with a detection limit of 0.06 μmol L−1 bromate. The effect of some strong oxidizing agents was studied, and the results showed that when such agents are present at levels of 2.5 to 5 times greater than the bromate in the solution, they can cause a maximum error of 3% in the determination of bromate in sulfuric acid electrolyte at pH 2.5.
48 citations
TL;DR: In this paper, the authors present a review of Li, Na, and Mg batteries using polymer electrolytes and present a suitable ion transport mechanism to suppress dendrite growth.
Abstract: Encouraged by the first report of ionic conductivity in 1973 and the consequent boom for the need of clean and green renewable energy resources, there has been a marked increase toward R&D of polymer electrolytes cum separator for energy storage devices. The most suitable alternative to the conventional energy storage devices is battery and it has the potential to fulfill the energy demand and could be used for storing energy produced from different alternative resources, i.e., wind/hydro/solar energy. Electrolyte is a key component of battery that plays a crucial role in its overall performance. The draft of the article is an attempt to present a coherent yet concise review of Li, Na, and Mg batteries using polymer electrolytes. The main topics given focus in this review are an introduction to properties shaping the polymer electrolytes, types of polymer electrolytes, and properties of constituents of polymer electrolytes (polymer host, salt, solvent, ionic liquid, plasticizer, nanofiller, nanoclay, nanorod, nanowire). The approaches to enhance the electrochemical properties are presented with a suitable ion transport mechanism. A special section is introduced to cover dendrite growth and strategies to suppress it. Important preparation methods and characterization techniques are introduced. The synopses of the experimental investigations are presented for ionic liquid/gel/composite polymer electrolytes. Finally, the future outlook highlights the further development for the next-generation energy storage devices.
44 citations
TL;DR: In this paper, a new strategy for constructing simultaneous determination of hydroquinone and catechol sensor was proposed by one-step pyrolysis of MIL series metal-organic frameworks materials (MIL-125 (Ti), MIL-101 (Cr), and MIL- 101 (Fe)) to obtain uniform-mixed carbon/metal oxide porous materials.
Abstract: It is a top priority to simultaneously and accurately detect hydroquinone (HQ) and catechol (CC). Here, a new strategy for constructing simultaneous determination of HQ and CC sensor was proposed by one-step pyrolysis of MIL series metal-organic frameworks materials (MIL-125 (Ti), MIL-101 (Cr), and MIL-101 (Fe)) to obtain uniform-mixed carbon/metal oxide porous materials (TiO2/C900, Cr2O3/C900, and Fe2O3/C900, respectively). And, cyclic voltammetry (CV) was utilized to investigate the electrochemical behavior of the composite materials. It was found that the simultaneous detection of catechol (CC) and hydroquinone (HQ) could be achieved by the sensor consisted of TiO2/C900 with the superior BET-specific surface area and micro-mesoporous characteristics. And, the linear range and detection limit of HQ and CC for the TiO2/C900 sensor were further studied. In addition, it was also found that the pyrolysis temperature and metal centers would affect the internal structures and component of the materials, thus affecting the properties of materials. The experiment provides a new idea for optimizing the simultaneous detection of the dihydroxybenzene isomers.
44 citations
TL;DR: In this article, a thin film of metallic Cu nanoparticles was synthesized by a one-pot chemical reduction method at ambient temperature, which was used for amperometric detection of glucose and for the chemical reduction of 4-nitrophenol.
Abstract: Thin film of metallic Cu nanoparticles was synthesized by a one-pot chemical reduction method at ambient temperature. Cu(II) acetate monohydrate and hydrazine monohydrate were used as precursor and reducing agent without additional surfactants to form uniform layer of Cu nanoparticle layer on a glass substrate (Cu/G). The XRD and the effectiveness of the electrocatalytic and catalytic properties of the Cu/G have been applied for an amperometric detection of glucose and for the chemical reduction of 4-nitrophenol. The former exhibited the detection limit as low as 2.47 μM with a linear range of 0.01–0.2 mM, while the latter showed the efficient catalytic activity with a high rate constant of 0.503/min. The current method suggested in this work might be useful for the fabrication of glass-based Cu nanoparticles electrodes for industrial and biomedical applications.
43 citations
TL;DR: In this paper, the effect of dispersion of Al2O3 nanoparticles on ionic conductivity of non-aqueous PVdF-HFP/PMMA blend-based nanocomposite gel polymer electrolyte system comprising liquid electrolyte of sodium trifluoromethanesulfonate is investigated.
Abstract: In the present work, the effect of dispersion of Al2O3 nanoparticles on ionic conductivity of non-aqueous PVdF-HFP/PMMA blend-based nanocomposite gel polymer electrolyte system comprising liquid electrolyte of sodium trifluoromethanesulfonate is investigated. The ionic conductivity of the electrolyte increases maximum to ∼ 1.5 × 10−3 S cm−1 for the composition with 6 wt% Al2O3 nanoparticles. The optimized composition retains Vogel-Tamman-Fulcher (VTF) behavior in the temperature range from − 50 to 95 °C. The scanning electron micrography and x-ray diffraction studies reveal the uniform dispersion of Al2O3 nanoparticles in the porous structure of the nanocomposite gel polymer electrolyte and enhanced amorphicity of polymer matrix. The optimized electrolyte composition owns a sufficiently large electrochemical stability window of ~ 3.6 V with good sodium ion transference number. The optimized electrolyte is used in a prototype sodium battery cell, which shows an open circuit potential of ~ 2.5 V and first discharge capacity ~ 400 mA h g−1 followed by a capacity decline with cycling.
41 citations
TL;DR: In this article, a nanocube of zeolitic imidazolate framework-67 (ZIF-67) was prepared by blending cobalt nitrate hexahydrate and 2-methylimidazole together in aqueous solutions containing hexadecyltrimethylammonium bromide (CTAB).
Abstract: In this study, a nanocube of zeolitic imidazolate framework-67 (ZIF-67) was prepared by blending cobalt nitrate hexahydrate and 2-methylimidazole together in aqueous solutions containing hexadecyltrimethylammonium bromide (CTAB). Then, grapheme oxide (GO) wrapped ZIF-67 nanocomposites (ZIF-67/GO-n) were prepared by one-pot stirring method at room temperature. The morphology and microstructure of ZIF-67 and its GO nanocomposites were investigated by Raman spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) specific surface area analysis. Electrochemical capacitance properties of all samples were characterized by cyclic voltammetry and chronopotentiometry, respectively. The results demonstrated that the content of GO used during synthesis process affected the specific capacity of nanocomposites while they were constructed as supercapacitor electrode. Compared with pure GO and ZIF-67 nanocubes, ZIF-67/GO-n composites had better specific capacitance. While the concentration of GO was 2 wt% based on their initial total mass of two reactants, ZIF-67/GO-2 composite presents a specific capacitance of 100.41 F g−1 at a sweep rate of 5 mV s−1. The good electrochemical performance of ZIF-67/GO-n composite may be credited to large BET surface area of ZIF-67 nanocubes and good conductivity of GO, and thus is expected to become a potential electrode material for supercapacitors.
39 citations
TL;DR: In this paper, the micro/nanostructures and surface hydrophobicity of the PbO2 surface were developed by using a typical electro-deposition process.
Abstract: Rational hydrophobic anode has been considered as a promising approach for water pollution remediation. However, the construction method of the hydrophobic electrode is limited, such as adding hydrophobic polymer materials. Herein, we address this limitation by developing Ce-modified Ti-PbO2 electrodes with distinctive micro/nanostructures and surface hydrophobicity by the typical electro-deposition process. The Pb ions in the lattice of PbO2 crystals can be substituted by cerium ions and the PbO2 crystal grains were refined when the concentration of cerium ions is low. Specifically, as further increase of the cerium content in plating solution, the CeO2 gradually precipitated on the surface of PbO2 and the PbO2 phase was becoming more and more amorphous. Namely, the pyramid structure converted to surface outshoots with outward oriented-growth, and then evolved gradually to branched projections, until the coral-like architecture was constructed by assembling of small particles. More importantly, the micro/nanostructures and surface hydrophobic PbO2 coatings can significantly enhance generating and utilizing efficiency of hydroxyl radicals, charge transfer rate, and electrochemical active area. The excellent electrochemical performance is mainly attributed to superior catalytic activity arises from synergetic effects between cerium and PbO2 and distinctive micro/nanostructures hydrophobicity surface of Ce-modified Ti-PbO2 electrodes.
38 citations
TL;DR: Graphene oxide modified polyvinyl alcohol/sodium sulfate-sodium molybdate (GO/PVA)-Na2SO4-Na2MoO4, GPSS) gel polymer electrolyte and NiMoO 4 electrode are integrated to fabricate carbon paper (CP) supercapacitor to improve capacitance performance.
Abstract: Graphene oxide–modified poly (vinyl alcohol)/sodium sulfate-sodium molybdate (GO/PVA-Na2SO4-Na2MoO4, GPSS) gel polymer electrolyte and nickel molybdate (NiMoO4) electrode are integrated to fabricate carbon paper (CP) supercapacitor to improve capacitance performance. GO in PVA gel can introduce an effective ion transport pathway to improve ionic conductivity of gel polymer electrolyte. The ionic conductivity increases from 3.73 mS cm−1 for PVA-Na2SO4 to 6.46 mS cm−1 for GO/PVA-Na2SO4 at optimal GO mass ratio of 0.6% in GO/PVA gel. It also obviously increases from 4.33 mS cm−1 for PVA-Na2SO4-Na2MoO4 to 28.86 mS cm−1 for GO/PVA-Na2SO4-Na2MoO4. Both Na2MoO4 electrolyte and NiMoO4 electrode show reversible redox electroactivity to provide superior pseudocapacitance. Accordingly, the CP supercapacitor using GPSS gel shows specific capacitance of 41.67 mF cm−2 and energy density of 70.02 mWh m−2 at 0.5 mA cm−2, presenting higher performance than 15.91 mF cm−2 and 26.74 mWh m−2 using GO/PVA-Na2SO4 gel. Furthermore, the NiMoO4/CP supercapacitor using GPSS gel shows even higher specific capacitance of 78.18 mF cm−2 and energy density of 131.39 mWh m−2 at 0.5 mA cm−2. It also exhibits high cycling capacitance retention of 85% at 0.5 mA cm−2 for 1000 cycles. The improved capacitance performance of CP supercapacitor using Na2MoO4 gel polymer electrolyte and NiMoO4 electrode is ascribed to reversible redox reaction of Mo(VI)/Mo(V), Mo(VI)/Mo(IV), and Ni(II)/Ni(III). The NiMoO4/CP supercapacitor using GO/Na2MoO4 gel polymer electrolyte becomes desirable for the promising application in energy storage devices.
TL;DR: In this article, the electrochemical performances of Al 0.5-Mg 0.1-Sn 0.05 Bi (wt%) alloys were investigated through electrochemical techniques and microstructure observation in 4-M NaOH solution.
Abstract: In this paper, the electrochemical performances of Al 0.5-Mg 0.1-Sn (wt%), Al 0.5-Mg 0.1-Sn 0.05 In (wt%), Al 0.5-Mg 0.1-Sn 0.05 Ga (wt%) and Al 0.5-Mg 0.1-Sn 0.05 Bi (wt%) alloys were investigated through electrochemical techniques and microstructure observation in 4 M NaOH solution. The results indicate that Al 0.5-Mg 0.1-Sn 0.05 In (wt%) alloy has the best discharge performance among all alloys, followed by Al 0.5-Mg 0.1-Sn 0.05-Bi (wt%) alloy, both of which is better than Al 0.5 Mg 0.1-Sn 0.05-Ga (wt%) alloy. This is due to the fact that the addition of indium to the Al 0.5-Mg 0.1-Sn-based alloy improves the discharge activity of the alloy while increasing its anodic efficiency. Although the addition of gallium or bismuth to this alloy increases the discharge activity, it reduces the efficiency of the anode, especially the addition of gallium resulting in severe intergranular corrosion of the alloy anode.
TL;DR: In this paper, a review highlights the key features of advanced carbon materials for application to commercial capacitor devices, including carbon aerogel/xerogel, templated carbons, carbide-derived carbons and carbon nanotubes, and graphene-based materials.
Abstract: Electrochemical capacitors are high-power energy storage devices having long cycle durability in comparison to secondary batteries. The energy storage mechanisms can be electric double-layer capacitance (ion adsorption) or pseudocapacitance (fast redox reaction) at the electrode-electrolyte interface. Most commonly used electrode materials are carbon materials with high specific surface area, microporous-activated carbons. A considerable number of studies have been conducted to optimize the pore structure and surface functionalities of activated carbons. In addition to conventional activated carbons, other types of carbon materials such as carbon aerogel/xerogel, templated carbons, carbide-derived carbons, carbon nanotubes, and graphene-based materials have been investigated. This review highlights the key features of advanced carbon materials for application to commercial capacitor devices.
TL;DR: In this paper, a galvanostatic electrolytic cell with the use of the platinum supported on Ti (Ti/Pt) and Ti/TiO2-nanotubes/PbO2 anodes was conducted in an electrochemical cell with 0.2L of solution containing 100mg−dm−3 of the textile dye acid red 1 (AR1) using Na2SO4 as supporting electrolyte.
Abstract: In this study, galvanostatic electrolysis, through the use of the platinum supported on Ti (Ti/Pt) and Ti/TiO2-nanotubes/PbO2 anodes, was conducted in an electrochemical cell with 0.2 L of solution containing 100 mg dm−3 of the textile dye Acid Red 1 (AR1) using Na2SO4 as supporting electrolyte, applying 7.5 and 60 mA cm−2. From the voltammetric curves, it was possible to understand that Ti/TiO2-nanotubes/PbO2 electrode has high oxygen evolution overpotential than Ti/Pt anode. A direct electron transfer reaction is attained between the dye molecules and Ti/Pt surface, at lower currents. Conversely, the AR1 oxidation involves water decomposition intermediates, mainly ·OH radicals at Ti/TiO2-nanotubes/PbO2 anode. The electrolytic process was monitored by the UV–visible spectrometry and the chemical oxygen demand (COD). Results clearly show that Ti/TiO2-nanotubes/PbO2 anode performs better than Ti/TiO2 in removing ARI due to the electrosynthesis of strong oxidants on its surface (·OH and persulfates), achieving a higher oxidation rate, higher current efficiency, and less energy consumption than Ti/Pt electrode.
TL;DR: In this article, a high-fidelity electrochemical-thermal coupling was established to study the polarization characteristics of power lithium-ion battery under cycle charge and discharge, and the results showed that for different working conditions, the polarization voltage difference of the power lithium ion battery is mainly affected by the change in polarization internal resistance.
Abstract: A high-fidelity electrochemical-thermal coupling was established to study the polarization characteristics of power lithium-ion battery under cycle charge and discharge. The lithium manganese oxide lithium-ion battery was selected to study under cyclic conditions including polarization voltage characteristics, and the polarization internal resistance characteristics of the power lithium-ion battery under cyclic conditions were analyzed via the Hybrid Pulse Power Test (HPPC). The results show that for different working conditions, the polarization voltage difference of the power lithium-ion battery is mainly affected by the change in polarization internal resistance. A higher charge-discharge rate, lower ambient temperatures, and more cycles lead to a greater polarization internal resistance of the battery. Meanwhile, the ohmic polarization internal resistance and the concentration polarization internal resistance of the power lithium-ion battery both exhibit different characteristics under different working condition. In addition, the internal resistance of the ohmic polarization is not affected by the change in current, but it is significantly affected by the change in ambient temperature. Therefore, the ohmic polarization voltage reacts rapidly with changes in the charge/discharge state of the battery; the change of the internal resistance of the concentration polarization is relatively slow.
TL;DR: In this article, the synergistic effect of graphene oxide nanocolloids (nano-GO) and silicon dioxide (silica) nanoparticles (SiO2-nanoparicles) has been used to modify a glassy carbon electrode (GCE) for the determination of gallic acid (GA).
Abstract: For the first time, the synergistic effect of graphene oxide nanocolloids (nano-GO) and silicon dioxide (silica) nanoparticles (SiO2-nanoparicles) has been used to modify a glassy carbon electrode (GCE) for the determination of gallic acid (GA). The modified electrode surface was characterised by using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXA) and Fourier transform infrared spectroscopy (FTIR). The electrochemical behaviour of the modified electrode was then studied, using cyclic voltammetry (CV) and differential pulse voltammetry (DPV), showing that the electrode was sensitive to GA in a concentration range of 6.25 × 10−6 to 1.0 × 10−3 mol L−1, with a correlation coefficient R2 of 0.9956 and a limit of detection of 2.09 × 10−6 mol L−1 (S/N = 3). The proposed method was successfully used for the determination of GA in red wine, white wine and orange juice, with recoveries of 102.3, 95.4 and 97.6%, respectively.
TL;DR: In this article, the performance of polyaniline (PANI)-based composites was tested by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) testing, and constant current charge and discharge (GCD) tests.
Abstract: Polyaniline, polyaniline/graphene composites were synthesized by a novel in situ chemical oxidative polymerization method including two oxidants. The morphology and structure of the material were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The electrochemical performance of polyaniline (PANI)-based composites was tested by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) testing, and constant current charge and discharge (GCD) tests. At 0.2 C of constant current, the discharge specific capacities of PANI/graphene oxide (PANI/GO) and PANI/GO-sodium borohydride (graphene oxide is reduced by sodium borohydride, named PANI/GO-NaBH4) were as high as 183 mAh/g and 192 mAh/g, respectively, which was nearly twice as high as that of PANI (100 mAh/g). After 100 charge and discharge cycles, the capacity retention rates of PANI, PANI/GO, and PANI/GO-NaBH4 were 80.4%, 89.4%, and 95.05%, respectively; the cycle performance was greatly improved before the modification. These results indicate that the composite has exciting potentials for the cathode material of zinc-rechargeable battery.
TL;DR: In this paper, a bimetallic (CoNi)-embedded nitrogen-enriched carbon framework was synthesized by a simple metal-doped zeolitic imidazolate framework thermal conversion strategy.
Abstract: Metal–organic framework (MOF) derivatives are excellent energy storage devices such as lithium–sulfur batteries. Here, a bimetallic (CoNi)-embedded nitrogen-enriched carbon framework was synthesized by a simple metal-doped zeolitic imidazolate framework thermal conversion strategy. CoNi-NC materials have a large specific surface area and a pore-rich structure. This unique structure interacts with a cobalt-based electroactive phase and a secondary metal to enhance electrochemical performance. By changing the molar ratio of nickel to cobalt and selecting the best bimetallic nitrogen-doped carbon framework, the initial discharge capacity of the lithium–sulfur battery with Co0.75Ni0.25-NC as the electrode material was 1278 mA h g−1 at 0.1 C, with excellent rate performance and good cycle stability.
TL;DR: In this paper, the effect of aluminum anodes treated with copper by chemical and electrochemical process to battery performance is investigated, and the surface characterization of this electrode is performed with a scanning electron microscope.
Abstract: For Al-air batteries, it is important to develop efficient and economical anodes. In this study, the effect of aluminum anodes treated with copper by chemical and electrochemical process to battery performance is investigated. The surface characterization of this electrode is performed with a scanning electron microscope. Electrochemical impedance spectroscopy and anodic polarization techniques are used. The hydrogen gas evolution and corrosion rate tests, the constant-voltage discharge tests, and the galvanostatic anodic dissolution tests are carried out. The anode utilizations are calculated. It is seen that the copper improves the anode efficiency by promoting the dissolution of aluminum according to battery reaction. However, it protects the aluminum from corrosion reaction by forming a barrier film without any restriction of battery reaction. It is understood from this work that the most efficient, economical, and practical method for copper deposition to electrode is the electrochemical deposition of copper. Furthermore, the 7075 alloy (Alloy/Cu) is more stable for both the electrochemical and chemical deposition process.
TL;DR: In this paper, the surface states of the alloys after constant current discharge were analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS).
Abstract: Al-0.05Ga-0.05Sn-0.05Pb-xMg alloys with different Mg content have been prepared. Electrochemical tests including constant current discharge test, current polarization test, electrochemical impedance spectroscopy (EIS) test, and Tafel test are performed. The surface states of the alloys after constant current discharge were analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS). X-ray diffraction (XRD) analysis was carried out. We find that different Mg contents have great influence on discharge performance of aluminum alloy anodes by changing the corrosion behavior. The SEM and XRD show that Mg can influence the distribution of corrosion and change the grain size to improve the discharge performance of aluminum anodes. Al-0.05Ga-0.05Sn-0.05Pb-0.1Mg shows the best electrochemical performance due to uniform corrosion and proper grain size. At 800 mA cm−2 constant current discharge, the potential of the aluminum anode can reach − 1.54 V (vs Hg/HgO), and the utilization ratio is over 98%.
TL;DR: In this article, a comparative Raman spectroelectrochemical study on polyaniline electrodeposited at a gold electrode was performed within the broad range of spectra excitation wavelengths from UV (325mm) through blue (442mm), green (532mm), red (633mm) to NIR (785mm) laser lines.
Abstract: A comparative Raman spectroelectrochemical study on polyaniline electrodeposited at a gold electrode was performed within the broad range of spectra excitation wavelengths from UV (325 nm) through blue (442 nm), green (532 nm), red (633 nm) to NIR (785 nm) laser lines. Two solutions of pH 2.0 and 8.0 were selected for protonated and deprotonated forms of polyaniline, and two limiting redox forms, a reduced (leucoemeraldine), and a fully oxidized one were taken into account. Raman spectra obtained and discussed reveal a strong enhancement of spectra for reduced form at a short wavelength excitation, and for oxidized form at red and NIR excitations. Raman features for all four polyaniline forms differing in protonation degree and redox state were analyzed and compared; excitation wavelength-dependent characteristic marker bands were suggested.
TL;DR: In this paper, the oxygen reduction kinetics on an La2NiO4+δ electrode for electrodes of different thicknesses were investigated by means of electrochemical impedance spectroscopy.
Abstract: The oxygen reduction kinetics on an La2NiO4 + δ electrode for electrodes of different thicknesses was investigated by means of electrochemical impedance spectroscopy. Dependences of the polarisation resistance in the temperature range from 700 to 800 °C, and oxygen pressure range of 0.2–16 kPa were obtained. It was established that three relaxation processes determined the overall polarisation resistance. Probable electrode reaction stages were suggested: oxygen ion diffusion on the electrode/electrolyte interface, charge transfer in the adsorption layer, oxygen surface exchange, and diffusion in La2NiO4 + δ. The influence of the electrode thickness on the electrochemical performance of La2NiO4 + δ electrodes was shown. The correlations between the electrochemical data and isotope exchange data are discussed.
TL;DR: In this article, an eco-friendly biopolymer electrolyte pectin with magnesium nitrate salt Mg(NO3)2 has been used to construct magnesium ion battery and the battery performance has been studied.
Abstract: Current research on electrochemical device application focuses on the usage of biopolymers like chitosan, pectin, agar-agar, cellulose acetate, and carrageenan as the electrolyte. The present work deals with the study of an eco-friendly biopolymer electrolyte pectin with magnesium nitrate salt Mg(NO3)2 prepared by solution casting technique. The prepared biopolymer electrolytes were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), AC impedance analysis, and linear sweep voltammetry (LSV). XRD analysis has been used to confirm the amorphous nature of the biopolymer pectin and magnesium nitrate salt. FTIR analysis has been used to confirm the complex formation between the polymer and the salt. DSC analysis has been used to find the glass transition temperature (Tg) of the prepared biopolymer electrolytes. AC impedance analysis has been used to study the electrical characterization of the prepared biopolymer electrolytes. The biopolymer electrolyte 50 M.wt% pectin:50 M.wt% Mg(NO3)2 has the highest ionic conductivity in the order of 10−4 S cm−1. The total ionic transference number of the highest conducting sample is 0.97 and the transference number of Mg2+ ion is 0.29. LSV has been used to find the electrochemical stability of the biopolymer electrolytes. The electrochemical stability of 50 M.wt% pectin:50 M.wt% Mg(NO3)2 is 3.8 V. This biopolymer electrolyte has been used to construct magnesium ion battery and the battery performance has been studied.
TL;DR: In this article, the performance of the hydrogen-bromate flow battery single cell has been optimized by varying the catholyte feed rate, LiBrO3 concentration in catholytes, hydrogen pressure, membrane thickness, amount of porous carbon at cathode, and Pt loading at anode.
Abstract: Hydrogen-bromate flow battery is a promising hybrid current source for air-deficient environment that functions by electrocatalyzed reactions of hydrogen oxidation and aqueous LiBrO3 reduction. The flow cell consists of porous carbonaceous cathode, platinum catalyzed hydrogen oxidation gas diffusion anode, and separating proton exchange membrane. Performance of the hydrogen-bromate flow battery single cell has been optimized by varying the catholyte feed rate, LiBrO3 concentration in catholyte, hydrogen pressure, membrane thickness, amount of porous carbon at cathode, and Pt loading at anode. Shape of the I-V curve is characterized by a sharp maximum of current, which indicates passivation of one of the electrodes. Combination of conventional reference electrode and home-made thin-film Luggin capillary has been used to monitor separately the polarizations of both flow cell electrodes. Poisoning of platinum hydrogen oxidation electrocatalyst by bromine species, which permeated the membrane, is shown as a major source of performance losses of hydrogen-bromate flow battery at high power density. Hypothesis supported by experiments claims that the degree of the platinum electrocatalyst poisoning is determined by the balance between the rates of the bromine species supply to anode and their removal by liquid water that permeates the membrane. Use of thinner proton exchange membrane and thinner carbonaceous cathode is a prerequisite to achieving high power density of the cell at high current efficiency of the cathode process. At 40 °C, area-specific power reaches 0.74 W cm−2 at the level of catholyte utilization equal to 0.93.
TL;DR: In this paper, a high energy density asymmetric supercapacitor cell consisting of polyaniline as a positive electrode and heteroatom-doped activated carbon as a negative electrode in aqueous sulfuric acid electrolyte is presented.
Abstract: We report herein a high energy density asymmetric supercapacitor cell consisting of polyaniline as a positive electrode and heteroatom-doped activated carbon as a negative electrode in aqueous sulfuric acid electrolyte. Polyaniline is prepared via oxidative polymerization of aniline using hydrothermally prepared manganese dioxide oxidant. Nitrogen and sulfur-doped activated carbon is prepared from AC by hydrothermal synthesis, employing ammonium thiocyanate as a heteroatom precursor. This asymmetric supercapacitor cell is cycled in the voltage range of 0 to 1.4 V, which exhibits an excellent performance with a high specific capacitance of 592 F g−1 and a high energy density of 80 W h kg−1 at a power density of 500 W kg−1, while symmetric cell configuration of individual components of polyaniline//polyaniline and activated carbon//activated carbon shows less performance, i.e., 35 W h kg−1 at 214 W kg−1 and 33 W h kg−1 at 286 W kg−1, respectively. Furthermore, asymmetric cells show good cycling stability retaining over 72% of its initial capacitance even after 10,000 continuous charge–discharge cycles at a higher discharge current, 5 mA. Practical device is demonstrated in the form of a CR2032 coin cell.
TL;DR: In this article, a solid-state supercapacitor is assembled using redox-mediated gel polymer as the electrolyte and separator and coconut shell-derived, steam-activated carbon as the electrodes.
Abstract: A solid-state supercapacitor is assembled using redox-mediated gel polymer as the electrolyte and separator and coconut shell–derived, steam-activated carbon as the electrodes. The gel polymer electrolyte (GPE) is based on poly(vinyl alcohol) (PVA)-potassium hydroxide (KOH)-hydroquinone (HQ), and is obtained using solution casting technique. Amorphous nature of the GPE is confirmed from XRD studies and the complex formation in the GPE is confirmed from FTIR spectral analysis. The GPE films are electrochemically characterized using impedance analysis, cyclic voltammetry and galvanostatic charge/discharge test. Self-discharge studies of the assembled supercapacitor are also carried out. Higher ionic conductivity around 53 mS cm−1 and superior flexibility serve as the main advantages of this redox-mediated GPE. The electrode-specific capacitance of the supercapacitor is found to be as high as 326.53 F g−1 with a capacity retention of 84.2% after being subjected 1000 charge-discharge cycles at a current density of 0.8 A g−1. The assembled supercapacitors are found to offer quite high energy density and power density around 33.15 Wh kg−1 and 689.58 W kg−1, respectively. These types of redox-mediated, flexible, gel polymer electrolytes are desirable for designing high power solid-state supercapacitors for energy storage applications.
TL;DR: In this paper, an amperometric-type sensor design made of ZrO2- and CaZrO3-based electrolytes is proposed for in situ water vapor partial pressure determination in oxidizing atmospheres and high temperatures.
Abstract: A way of in situ water vapor partial pressure determination in oxidizing atmospheres and high temperatures is proposed in this work, utilizing a new and simple amperometric-type sensor design made of ZrO2- and CaZrO3-based electrolytes. These electrolyte membranes allow conduction of oxygen-anions and protons, resulting in full water decomposition on account of the applied potential through an external electrical circuit. At a certain range of applied voltages, a limiting current condition is observed. By plotting the limiting current against temperature and water vapor partial pressure, the functional dependences are obtained, which could be used as the calibration curves for analytical reasons. The proper operation of the developed sensor is confirmed by changing water vapor partial pressures (0.003–0.110 atm) in air and temperatures (675–750 °C). It is found that the sensor’s reading is stable, reproducible, and corresponds to the theoretically predicted values, confirming the test success. The obtained results allow extending the field of possible applications of oxide materials with proton conduction nature.
TL;DR: In this paper, a series of rationally designed hybrid membranes composed of poly(vinylidene fluoride) (PVDF) as polymer matrix and silica nanoparticles (SiO2) as inorganic fillers are prepared by combining slurry coating method and phase inversion method.
Abstract: In this work, a series of rationally designed hybrid membranes composed of poly(vinylidene fluoride) (PVDF) as polymer matrix and silica nanoparticles (SiO2) as inorganic fillers are prepared by combining slurry coating method and phase inversion method. The effects of the added SiO2 nanoparticles on the porosity, electrolyte wettability, thermal stability, and ionic conductivity of PVDF/SiO2 hybrid membranes are investigated systematically. Compared to the commercial polypropylene (PP) membrane, PVDF/SiO2 hybrid membranes present enhanced physical and electrochemical performance. Particularly, the incorporation of 5 wt.% SiO2 to PVDF polymer matrix (PVDF5 hybrid membrane) shows the highest ionic conductivity of 1 × 10−3 S cm−1 at 25 °C among all the samples. The electrochemical tests demonstrate that the LiNi0.8Co0.1Mn0.1O2/Li coin cell assembled with PVDF5 hybrid membrane exhibits high reversible discharge capacity (179 mAh g−1 at 0.05 C), excellent cyclic stability (169 mAh g−1 after 100 cycles at 0.1 C), and superior rate performance, which are much better than other counterparts and PP separator. Moreover, as for the large capacity battery application, 1.1 Ah LiNi0.8Co0.1Mn0.1O2/graphite pouch cell with PVDF5 hybrid membrane can deliver a high discharge capacity of 992 mAh and good Coulombic efficiency of 99.5%. Evidently, the optimized PVDF/SiO2 hybrid membrane will be a very promising alternative to the commercial PP separator for advanced lithium-ion batteries.
TL;DR: In this article, the effect of ionic liquid 1-ethyl-3methylimidazolium bis(fluorosulfonyl)imide (EMIMFSI) on polymer poly(ethylene oxide) (PEO) and salt lithium bis(trifluoromethylsulfonyls)imides (LiTFSI) electrolyte system was reported.
Abstract: In this paper, we report the effect of ionic liquid 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIMFSI) on polymer poly(ethylene oxide) (PEO) and salt lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) electrolyte system. The glass transition temperature and degree of crystallinity decreased with an increasing amount of EMIMFSI resulting in an increase in the ionic conductivity. The highest room temperature ionic conductivity and Li+ transference number are observed for PEO + 20 wt% LiTFSI + 10 wt% EMIMFSI. These prepared gel polymer electrolytes (GPEs) are thermally and electrochemically stable enough for battery application. Two different cells with graphene oxide-doped lithium iron phosphate, LiFePO4 (GO-LFP) and lithium nickel cobalt aluminum oxide, LiNi0.80Co0.15Al0.05O2 (NCA) cathodes were tested with prepared GPEs. GO-LFP showed more predictable and consistent nature of capacity fading and good discharge capacity. However, NCA showed higher discharge capacity, better cyclic performance, lower capacity fading, and better performance at high C rates.
TL;DR: In this paper, the delaminated d-Ti3C2Tx and MnO2 composites were prepared by a simple synthesis method, and the substrate of the composite is the conductive d-Tc2Tx sheet.
Abstract: Ti3C2Tx is one of the typical MXene materials, where Tx stands for various surface terminations (OH, O, and/or F groups). In this paper, the delaminated Ti3C2Tx, referred to as d-Ti3C2Tx, and MnO2 composites were prepared by a simple synthesis method. The substrate of the composite is the conductive d-Ti3C2Tx sheet. The MnO2 was grown on the surface of d-Ti3C2Tx and it can increase the specific capacitance of the composite. At the same time, the d-Ti3C2Tx substrate can provide a carrier for the growth and uniform dispersion of MnO2. Therefore, the d-Ti3C2Tx/MnO2 composite has high specific capacitance and good cycle stability. At a current density of 1 A g−1, the d-Ti3C2Tx/MnO2 composite has a specific capacitance of 242 F g−1, which is three times than that of Ti3C2Tx. The electrode capacitance retention rate can still reach 97% after 5000 cycles of galvanostatic charge and discharge.