Cost-effective Electrode Research Articles

Candied-Haws-like Architecture Consisting of FeS2@C Core–Shell Particles for Efficient Potassium Storage

The major challenge faced by potassium-ion batteries (PIBs) lies in the shortage of high-performance and cost-effective electrode materials. Herein, we demonstrate a candied-haws structure containi...

Facile synthesis of MoS2 nanosheets-deposited TiO2 nanotubes array electrode for enhanced electrocatalytic hydrogen evolution reaction

MoS2 nanosheets were fabricated by ultrasonication of bulk MoS2 and TiO2 nanotubes array (TNA) was formed on Ti foil via anodization method. Using facile and binder-free electrophoretic technique, MoS2 nanosheets were deposited on the TNA as high surface area and well-ordered support to fabricate the MS/TNA electrode. In electrocatalytic hydrogen evolution reaction (HER), the MS/TNA indicated a low onset potential and overpotential of 85 mV at current density of −10 mA/cm2 with Tafel slope of 39 mV/dec. Furthermore, after 1000 cycles, the MS/TNA displays high stability in HER. Our results demonstrated that the MoS2 nanosheets on the TNA provide more active sites while the ordered tubular TNA support creates straight pathways for electron transport toward MoS2 nanosheets with improved interaction of the electrolyte and electrode in HER. This work introduces the MS/TNA as an efficient and cost-effective electrode for electrocatalytic production of hydrogen.

High transparent, low surface resistance ZTO/Ag/ZTO multilayer thin film electrodes on glass and polymer substrates

Zinc tin oxide (ZTO)/Ag/ZTO multilayer thin films were grown by direct current (DC) magnetron sputtering technique at room temperature on soda lime glass (SLG) and different polymer substrates such as polycarbonate (PC) and polyethylene terephthalate (PET) for transparent conductive electrode (TCE) applications. The effect of substrate on the structural, optical and electrical characteristics of ZTO/Ag/ZTO multilayers was investigated. All prepared ZTO/Ag/ZTO films presented amorphous structure as expected from room temperature deposition process and smooth surface quality with very low surface roughness. We found that ZTO/Ag/ZTO multilayer films grown on SLG, PET and PC substrates have very high optical transmission and low surface resistance. Moreover, after ZTO/Ag/ZTO multilayer thin film deposition on polymer substrates, the optical transmission was found to be enhanced because the higher absorption due to Ag layer is compensated by lower reflectance. Our results suggest that ZTO/Ag/ZTO multilayer thin films on any substrate can be a promising alternative to indium tin oxide (ITO) films as a cost-effective, indium-free, flexible and transparent electrode for various applications.

Recent Advances in Rechargeable Batteries with Prussian Blue Analogs Nanoarchitectonics

Sustainable energy storage system requires high-performance rechargeable batteries with earth-abundant elements and cost-effective electrodes. Prussian blue (PB) and its analogs (PBAs) are a large family of materials with open frameworks. Benefiting from nanoarchitectonics, the PBAs are receiving great attention as cathodic materials for various rechargeable batteries. In this review, we present a general summary and evaluation on the recent advances of PBAs for the rechargeable batteries applications. The general synthetic methods and the chemical properties of PBAs have also been discussed. This review aims to provide a brief outlook on the current and future research strategies of PBAs in the electrochemical energy storage.

NiS2 as a cost effective counter electrode for dye sensitized solar cell

Michael Gratzel invented dye sensitized solar cell (DSSC) in 1991. Counter electrode (CE) acts a significant part to convert light energy to solar energy in DSSC. Hydrothermal method was used to prepare an inexpensive nickel sulfide (NiS2) counter electrode to replace expensive platinum CE and it was examined by using X-ray diffraction (XRD), cyclic voltammetry, electrochemical impedance and photovoltaic performance studies. The achieved photo-conversion efficiency of NiS2 based DSSC was 4.55% under 1 sun illumination. This suggests NiS2 nanoparticles could serve as non-precious alternate CE for DSSC applications.

All-Organic, Solution-Processed, Extremely Conformal, Mechanically Biocompatible, and Breathable Epidermal Electrodes.

Conformal integration of an epidermal device with the skin, as well as sweat and air permeability, are crucial to reduce stress on biological tissues. Nanofiber-based porous mesh structures (breathable devices) are commonly utilized to prevent skin problems. Noble metals are normally deposited on nanomesh substrates to form breathable electrodes. However, these are expensive and require high-vacuum processes involving time-consuming multistep procedures. Organic materials are suitable alternatives that can be simply processed in solution. We report a simple, cost-effective, mechanically biocompatible, and breathable organic epidermal electrode for biometric devices. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is sprayed on a nanofiber-mesh structure, treated using only heat and water to enhance its biocompatibility and conductivity, and used as the electrode. The treatment is accomplished using an autoclave, simultaneously reducing the electrical resistance and sterilizing the electrode for practical use. This research can lead to affordable and biocompatible epidermal electrodes with improved suitability for various biomedical applications.

Saline Water-Based Mineralization Pathway for Gigatonne-Scale CO2Management

This perspective proposes a potential pathway to diminish atmospheric CO2 accumulations which is distinct from traditional carbon capture and geological sequestration strategies and from existing negative emissions technologies (NETs). Unlike conventional sorbent- or solvent-based CO2 capture processes where substantial energy expenditures are associated with demixing and desorbing CO2, the single-step carbon sequestration and storage (sCS2) approach relies on electrolytic carbonate mineral precipitation using renewable energy within a simple and scalable process design. Although numerous approaches have implied electrolysis for carbon management, the sCS2 approach is unique in the following ways: (1) CO2 mineralization for promoting solid carbonate formation: The thermodynamic and kinetic barriers to carbonate precipitation are overcome by direct and in situ electrochemical forcing to stabilize dissolved inorganic carbon and divalent cations [Ca,Mg] to form carbonate minerals. (2) Flow-through membraneless electrolysis: A flowing electrolyte (seawater) is dissociated while in motion. The process utilizes cost-effective mesh electrodes while also decreasing the number of components and assembly steps and reducing the risk of device failure. (3) Integrated electrolytic reactor–rotary drum filter: An electroactive thin-film mesh cathode (eTFC) is suggested to be integrated within a rotary drum filter configuration, allowing for the filtration of dilute and polydispersed mineral precipitates at a low energy cost. These attributes render sCS2 as an approach worthy of more detailed evaluation, development, and scaling for global-scale carbon management.

Hierarchical CoP Nanostructures on Nickel Foam as Efficient Bifunctional Catalysts for Water Splitting.

A highly active and cheap catalyst is also key to hydrogen production by water splitting. However, most of the high-efficiency catalysts reported to date only are catalytically active for either the hydrogen evolution reaction (HER) or the oxygen evolution reaction (OER), which makes the development of multifunctional catalysts more meaningful. Here, for the first time, Co(CO3 )0.5 OH. 0.11 H2 O (CHCH) as precursor with different microstructures on the surface of nickel foam (NF) was obtained using a facile hydrothermal method. The CoP/NF catalyst was obtained after thermal phosphating that retained the microhierarchical structure of the precursor and greatly improved the catalytic performance, with a highly efficiency performance as HER and OER dual-functional catalyst. Density functional theory (DFT) calculations showed that the possible reason for the excellent performance of the CoP/NF layered structure is an increase in the number of of surface defects and an increased active surface area. The results reported in this paper show that CoP/NF, a layered bifunctional electrocatalyst, is a cost-effective and efficient water-splitting electrode. This finding can offer the opportunity for the commercial use of excess electric energy for large-scale water splitting hydrogen production.

Conductive electrodes of metallic-organic compound CH3CuS nanowires for all-solid-state flexible supercapacitors.

Development of wearable electronics puts forward higher requirements for flexible energy storage devices. Lighter and thinner electrodes with high conductivity are one of the key factors to meet this demand. Herein, a conductive paper-based electrode, assembled from metallic-organic compound CH3CuS nanowires prepared by a one-step thermal solution process, is reported. By using the conductive electrodes of CH3CuS nanowires, the fabricated all-solid-state supercapacitor device delivers an excellent electrochemical performance: an areal capacitance of 90.5 μF cm-2 at a current density of 0.5 mA cm-2, an energy density of 5.2 μW h cm-2, and 98% retention of initial capacitance after undergoing 10 000 cycles. In particular, the fabricated all-solid-state supercapacitor device can work normally under a bent state. The no-additive, cost-effective, and eco-friendly paper-based electrodes present a potential application prospect in the field of flexible energy storage devices.

All-Polymer Wearable Thermoelectrochemical Cells Harvesting Body Heat

Wearable thermoelectrochemical cells (thermocells) have attracted increasing interest due to their ability to turn human body heat into electricity. Here, we have fabricated a flexible, cost-effective, and 3D porous all-polymer electrode on an electrical conductive polymer substrate via a simple 3D printing method. Due to the high degree of electrolyte penetration into the 3D porous electrode materials for redox reactions, the all-polymer based porous 3D electrodes deliver an increased power output of more than twice that of the film electrodes under the same mass loading using either n-type or p-type gel electrolytes. To realize the practical application of our thermocell, we fabricated 18 pairs of n-p devices through series connection of n-type and p-type single devices. The strap shaped thermocell arrangement was able to charge up a commercial supercapacitor to 0.27 V using the body heat of the person upon which it was being worn and in turn power a typical commercial lab timer.

Mn-Fe3O4 nanoparticles anchored on the urushiol functionalized 3D-graphene for the electrochemical detection of 4-nitrophenol

Preparation of highly active and cost-effective electrode materials is of great interest in electrochemical detection. In this study, a simple urushiol-templated solvothermal method combined with calcination was proposed to fabricate N-doped three-dimensional graphene (3D-G) with Mn-doped Fe3O4 nanoparticles loaded on the surface (Mn-Fe3O4/3D-G). Because of the large active surface area, porous channel and high loading ratio of Mn-Fe3O4 nanoparticles, as-prepared Mn-Fe3O4/3D-G sensor showed high activity on the determination of 4-nitrophenol (4-NP), which are much improved from the control un-modified samples. The wide linear concentration range (5–100 μM), low detection limit (19 nM) and satisfactory recovery of 4-NP in various water samples (98.38–100.41%) indicated that the Mn-Fe3O4/3D-G electrode can be potentially used for real-world applications. This study gives a simple but meaningful strategy for constructing transition metal oxide/graphene composite materials with high electrocatalytic activity.

Hole transport free flexible perovskite solar cells with cost-effective carbon electrodes

Low temperature derived carbon electrodes are employed to fabricate low cost hole transport layer free perovskite solar cells, in which perovskite films annealed in glovebox and ambient air are used as the absorbers, respectively. Results suggest that the air annealed sample has bigger crystal grains and higher crystallinity, and the existence of a small amount of lead iodide which passivates grain boundaries contributes to a lower trap density. As a result, a maximum power conversion efficiency (PCE) of 13.07% was obtained on the air annealed device, which is higher than those of devices annealed in glovebox (11.25%). Furthermore, the stability of unencapsulated devices stored in wet (with humidity around 90% ± 5%) air atmosphere are investigated and the results prove that our devices exhibit good stability. In addition to rigid devices, flexible perovskite solar cells are also fabricated using the same procedure. The highest PCE of 11.53% is demonstrated on the champion flexible device, and 69% of its initial PCE can be maintained even after 2000 bending cycles with a bending radius of 2 mm. Our work provides a promising and simple rout for low-cost, air-stable, high-efficiency carbon perovskite solar cells for both large area production and flexible electronic devices industry.

Fabrication of a Novel, Cost-Effective Double-Sided Indium Tin Oxide-Based Nanoribbon Electrode and Its Application of Acute Toxicity Detection in Water.

Microelectrode plays a crucial role in developing a rapid biosensor for detecting toxicity in water. In this study, a nanoribbon electrode (NRE) with amplified microelectrode signal was successfully prepared by electrodepositing 2-allylphenol on a double-sided indium tin oxide glass. The NRE provided a simple mean for obtaining large steady-state current response. Its advantages were discussed by contrasting the toxicity detection of 3,5-dichlorophenol (DCP) with single microelectrode, microelectrode array, and millimeter electrode as working electrodes in which potassium ferricyanide (K3[Fe(CN)6]) was adopted as a mediator, and Escherichia coli was selected as bioreceptor. At a constant potential of 450 mV, the current reached a steady state within 10 s. The biosensor was constructed using the NRE as working electrode, and its feasibility was verified by determining the toxicity of DCP. A 50% inhibitory concentration (IC50) of 3.01 mg/L was obtained by analyzing the current responses of different concentrations of DCP within 1 h. These results exhibited that the proposed method based on the as-prepared NRE was a rapid, sensitive, and cost-effective way for toxicity detection in water.

Hybrid NiO-CoO nanocomposite for high energy supercapacitor applications

Energy storage research is focusing new cost effective and high specific capacitance electrode materials to meet the requirements of the energy demands. Herein, we studied hydrothermal derived hybrid NiO-CoO nanocomposite for supercapacitor applications. Electrochemical analysis of hybrid NiO-CoO nanocomposite of different reaction time was characterized and the obtained corresponding specific capacitance values were 168, 169 and 298 F/g respectively at 10 mV/s. Hybrid electrodes, suitable incorporation of CoO with NiO process increasingly enhanced electronic conductivity and electrochemical performance. 94.30% cyclic performance was maintained over 5000 cycles of charge discharge in galvanostatic charge discharge (GCD) profile.

High-Performance and Durable Membrane Electrode Assemblies Fabricated By Reactive Spray Deposition Technology for Proton Exchange Membrane Electrolyzers

Water electrolysis is a very old and promising technology for hydrogen production that started about two centuries ago. Hydrogen, considered the best source for fuel and energy storage, can be produced by the electrochemical conversion of water into hydrogen and oxygen through the water electrolysis process. Since the 1950s, proton exchange membrane water electrolyzers (PEMWEs) have been commercially developed as a green source of high-purity hydrogen for many chemical applications as well as energy storage. However, high cost, high maintenance, low durability, poor safety, poor reliability, and low efficiency of PEMWEs compared to other available technologies have hampered their widespread commercialization. To address the economic and technical issues of the PEMWEs, research should consider improved electrocatalysts, low cost electrodes, corrosive resistant electrodes, reduction of electrode surface tension, and lower membrane resistance and hydrogen crossover [1, 2].This work presents high-performance, cost-effective and durable membrane electrode assemblies (MEAs; 86 cm2 active area) developed by the unique reactive spray deposition technology (RSDT) [3-6]. The RSDT-fabricated MEAs possess total platinum group metal (PGM) loading of 0.2-0.3 mgPt cm-2 for the Pt/C cathode catalyst layer, and 0.2-0.3 mgIr cm-2 for the Ir/IrOx anode catalyst layer, respectively. This is an order of magnitude reduction of the PGM loadings in the catalyst layers in comparison to the state-of-the-art commercial MEAs, resulting in substantial reduction of the cost of PEMWEs. An ultra-thin Pt recombination layer (Pt RL), positioned between two PEM membranes, was fabricated by RSDT to lower hydrogen cross-over and eliminate the PEMWE’s safety concerns. Furthermore, the RSDT-fabricated MEAs showed stable performance for 3000 hours operation at 1.8 A cm-2, 50°C, 400 psi hydrogen pressure and ambient oxygen pressure without significant loss in the polarization performance.

Anchoring CoS on three-dimensional porous rGO thin films as efficient counter electrodes for dye-sensitized solar cells

Rational design of advanced cost-effective counter electrode (CE) is vital for the development of dye-sensitized solar cells (DSSCs). Herein, we report a novel CoS/reduced graphene oxide (CoS/rGO) composite counter electrode via a facile and rapid microwave irradiation plus ion exchange method. CoS nanoparticles are strongly anchored on three-dimensional (3D) porous rGO thin films. Due to positive advantages including high catalytic properties, enhanced active area, and electrical conductivity, the DSSC based on CoS/rGO counter electrode is endowed with a power conversion efficiency (PCE) of 6.86%, superior to that based on sputtered Pt counter electrode (6.50%). Our results indicate that CoS/rGO composite thin film is a low-cost and highly efficient CE for DSSCs.

High-performance and cost-effective membrane electrode assemblies for advanced proton exchange membrane water electrolyzers: Long-term durability assessment

Improved activity and durability performance of a two-cell (86 cm2) proton exchange membrane water electrolyzer (PEMWE) stack is reported for the first time. Both membrane electrode assemblies (MEAs) contain one order of magnitude lower platinum group metal (PGM) loadings compared to the state-of-the-art PEMWEs and incorporate novel Pt recombination layers. The high-performance and cost-effective MEAs are fabricated by the unique reactive spray deposition technology (RSDT). This advanced methodology allows for one-step fabrication of MEAs and ensures precise control and distribution of the catalyst composition and loading. The RSDT-fabricated MEAs contain only 0.2 and 0.3 mgPGM cm−2 loading in the cathode and anode electrodes, respectively, and demonstrate excellent activity and durability for over 3000 h of operation at industrially-relevant operating conditions without showing significant loss in performance. This novel work shows that a significant cost reduction for PEMWEs is achieved while maintaining excellent durability, high catalysts activities, and low hydrogen cross-over.

Low-Temperature Multielement Fusible Alloy-Based Molten Sodium Batteries for Grid-Scale Energy Storage.

The sustainable future of modern society relies on the development of advanced energy systems. Alkali metals, such as Li, Na, and K, are promising to construct high-energy-density batteries to complement the fast-growing implementation of renewable sources. The stripping/deposition of alkali metals is compromised by serious dendrite growth, which can be intrinsically eliminated by using molten alkali metal anodes. Up to now, most of the conventional molten alkali metal-based batteries need to be operated at high temperatures. To decrease the operating temperature, we extended the battery chemistry to multielement alloys, which provide more flexibility for wide selection and rational screening of cost-effective and fusible metallic electrodes. On the basis of an integrated experimental and theoretical study, the depressed melting point and enhanced interfacial compatibility are elucidated. The proof-of-concept molten sodium battery enabled by the Bi–Pb–Sn fusible alloy not only circumvents the use of costly Ga and In elements but also delivers attractive performance at 100 °C, holding great promise for grid-scale energy storage.

Impact of low temperature plasma annealing for flexible, transparent and conductive ITO/PEDOT:PSS composite electrode

We report on the development of a cost effective, highly transparent flexible conductive electrode for energy conversion devices using the ITO/PEDOT:PSS nanocomposite. The ITO/PEDOT:PSS nano composite thin film was deposited via bar coating, then its characteristics were examined. In particular, we study any changes in its transparency and resistance. The thin film transparent ITO/PEDOT:PSS was annealed using a low temperature annealing technique called plasma annealing. The purpose of low temperature plasma annealing is to help excite the electrons from their bonding states in the valence band into the antibonding states of the conduction band where a second order phase transition occurs. This study investigates the influence of O2 plasma annealing on the resistance of the nano composite thin films. The included PEDOT:PSS supports the flexibility of the ITO, as pristine ITO is brittle. High optical transmittance of 93.73% at 550nm and a reduction in the sheet resistance were achieved using this plasma annealing from 1105 Ω/□ to 535 Ω/□ on the ITO/PEDOT:PSS nano composite making them excellent candidates to develop as cost effective flexible transparent electrodes that can be used as thin film heaters.

In-situ hydrothermal synthesis of δ-MnO2/soybean pod carbon and its high performance application on supercapacitor

Manganese dioxide, with large theoretical capacitance, is a promising electrode material of supercapacitors, while the poor cyclic stability limits its practical application. Traditional carbon loading using graphene or carbon nanotube is still unsatisfactory due to high cost. In this study, renewable waste of soybean pod was utilized as the precursor of carbon matrix. The MnO2/soybean pod carbon composite material was synthesized by a one-step in-situ hydrothermal method. The composite material displayed natural tube structure, and its surface was sheathed with numerous δ-MnO2 nanorods. After carbon loading, the MnO2/soybean pod carbon delivered a superior specific capacitance of 530 F g–1 in Na2SO4 electrolyte as the three-electrode system, 46% higher than 362 F g–1 of pristine MnO2. Using the symmetrical two-electrode system, such the composite electrode further revealed high capacitance retention of 91% and reversible capacitance of 189 F g–1 after 6000 charge/discharge cycles. It demonstrates that this work develops a scalable strategy to obtain high-performance and cost-effective electrode material of next-generation supercapacitors.