Traditional Electrode Research Articles

GHz surface waves in Al/LiTaO3/Si composite: Effect of the Drude electrode on dispersion, attenuation and mode shapes

In fifth generation (5G) mobile communication, radio frequency is in the super high frequency range (3–30 GHz). Thus, different from Ohm law, electrode loss at GHz frequency becomes frequency-dependent. As such, many properties, especially attenuation of piezoelectric acoustic devices, should be reevaluated. In this paper, the attenuation of GHz surface wave propagating in composite structure made of metal electrode, piezoelectric film and elastic half space is investigated based on the loss model of Drude electrode. Specifically, the Al/LiTaO3/Si composite is considered where Rayleigh mode and SH mode are fully coupled. Based on the Stroh-type formalism, the dispersion equations of the composite with the Drude electrode are derived, and compared with the traditional perfect conductor electrode which is under the short circuit boundary condition. The phase velocity, attenuation and wave mode shapes are obtained successfully by the multidimensional moduli ratio convergence method. Numerical results are presented to reveal some interesting intrinsic features, which include two analytical upper bounds of phase velocity, nonexistent validation of intersection points in dispersion curves, and relations among veering, attenuation jumps and wave-mode conversions. These features and relations provide an in-depth insight for GHz wave motion properties in piezoelectric composites.

Rational design of electrochemical energy storage and thermal energy storage double network aerogel for in-situ temperature regulation of supercapacitors

During the charging/discharging process, a large amount of heat is constantly generated inside the supercapacitor. Therefore, thermal management of supercapacitors is crucial. In this work, a calcium alginate/polyaniline/polyethylene glycol (CA/PANI/PEG) double network multifunctional aerogels were prepared for thermal energy storage and electrochemical energy storage Due to the strong hydrogen bonding between PANI and CA and ionic cross-linking between CA molecular chains, the CA/PANI double network structure can be used to solidify PEG. CA/PANI/PEG aerogels can form stable porous network structures with excellent properties. For example, due to the in-situ thermal management of CA/PANI/PEG, CA/PANI/PEG exhibits a higher specific capacitance than the traditional PANI-based electrode at 55 °C. More importantly, the CA/PANI/PEG aerogel not only possessed a high enthalpy of phase transition (162.1 J/g) but also showed superior capacitive performance (175 mF/cm2 at 0.1 mA/cm2 at 55 °C). After 10,000 charge/discharge cycle tests, it can maintain 84.5 % of the initial capacitance. This study opens up a new way for the development and application of PCMs in the thermal management of supercapacitors.

"Bubble-Diode" Breathable Electrodes for Fast Gas Transport.

Bubbles arising from wild gas evolution commonly exist in electrochemical systems, particularly in water electrolysis and rechargeable aqueous batteries (e. g., Zn-air batteries). Substantial energy dissipation occurs due to the obstruction of active sites and ion-conducting pathways by evolving bubbles. Efforts are made to elucidate effective strategies for fast gas transport, most of which focus on minimizing bubble size and facilitating their timely detachment through complex techniques such as constructing super-hydrophilic nano-structure electrodes, flowing electrolytes, and ultrasonic oscillation. Recently, an innovative, facile, and highly efficient method utilizing a breathable electrode design to promote gaseous molecules to the external environment emerges as a promising approach since it avoids remarkable bubble accumulation while remaining free of additional accessories. This paper highlights the origin and evolution of this promising design. Starting with introducing the basic concept of traditional breathable electrodes based on hydrophobic polymer networks and discussing the current progress made in underlying mechanisms, a detailed description of the advanced design inspired by a "bubble-diode" concept with superior breathability follows. This Concept aims to contribute to a deep understanding of this technology and paves the way for further advancements in this renewable energy era.

Chemically synthesized poly(3,4-ethylenedioxythiophene) conducting polymer as a robust electrocatalyst for highly efficient dye-sensitized solar cells.

Chemically synthesized PEDOT (poly(3,4-ethylenedioxythiophene)) nanomaterials, with various nanostructured morphologies as well as different intrinsic electrical conductivities and crystallinities, were compared as electrocatalysts for Co(III) reduction in dye-sensitized solar cells (DSSCs). Electrochemical parameters, charge transfer resistance toward the electrode/electrolyte interface, catalytic activity for Co(III)-reduction, and diffusion of cobalt redox species greatly depend on the morphology, crystallinity, and intrinsic electrical conductivity of the chemically synthesized PEDOTs and optimization of the fabrication procedure for counter electrodes. The PEDOT counter electrode, fabricated by spin coating a DMSO-dispersed PEDOT solution with an ordered 1D structure and nanosized fibers averaging 70 nm in diameter and an electrical conductivity of ∼16 S cm-1, exhibits the lowest charge transfer resistance, highest diffusion for a cobalt redox mediator and superior electrocatalytic performance compared to a traditional Pt-counter electrode. The photovoltaic performance of the DSSC using chemically synthesized PEDOT exceeds that of a Pt-electrode device because of the enhanced current density, which is directly related to the superior electrocatalytic ability of PEDOT for Co(III)-reduction. This simple spin-coated counter electrode prepared using cheap and scalable chemically synthesized PEDOT can be a potential alternative to the expensive Pt-counter electrode for cobalt and other redox electrolytes in DSSCs and various flexible electronic devices.

HDE-Array: Development and Validation of a New Dry Electrode Array Design to Acquire HD-sEMG for Hand Position Estimation.

This paper aims to introduce HDE-Array (High-Density Electrode Array), a novel dry electrode array for acquiring High-Density surface electromyography (HD-sEMG) for hand position estimation through RPC-Net (Recursive Prosthetic Control Network), a neural network defined in a previous study. We aim to demonstrate the hypothesis that the position estimates returned by RPC-Net using HD-sEMG signals acquired with HDE-Array are as accurate as those obtained from signals acquired with gel electrodes. We compared the results, in terms of precision of hand position estimation by RPC-Net, using signals acquired by traditional gel electrodes and by HDE-Array. As additional validation, we performed a variance analysis to confirm that the presence of only two rows of electrodes does not result in an excessive loss of information, and we characterized the electrode-skin impedance to assess the effects of the voltage divider effect and power line interference. Performance tests indicated that RPC-Net, used with HDE-Array, achieved comparable or superior results to those observed when used with the gel electrode setup. The dry electrodes demonstrated effective performance even with a simplified setup, highlighting potential cost and usability benefits. These results suggest improvements in the accessibility and user-friendliness of upper-limb rehabilitation devices and underscore the potential of HDE-Array and RPC-Net to revolutionize control for medical and non-medical applications.

Flexible and stretchable implantable devices for peripheral neuromuscular electrophysiology.

The peripheral nervous and muscular system, a cornerstone of human physiology, plays a pivotal role in ensuring the seamless functioning of the human body. This intricate network, comprising nerves and muscles extending throughout the body, is essential for motor control, sensory feedback, and the regulation of autonomic bodily functions. The qualified implantable peripheral interface can accurately monitor the biopotential of the target tissue and conduct treatment with stimulation, enhancing the human-machine interaction and new achievements in disease cure. Implantable electrodes have revolutionized the field of neuromuscular interfaces, offering precise bidirectional communication between the neuromuscular system and external devices. They enable natural control for individuals with limb loss, bridging the gap between mind and machine and aiding neuromuscular rehabilitation. In research and medical diagnostics, implantable electrodes provide invaluable tools for studying neuromuscular function and the development of therapies. However, traditional rigid electrodes face challenges due to the dynamic nature of the peripheral neuromuscular system. Flexible and stretchable devices show immense promise in accommodating dynamic alterations, offering adaptability, and accurate monitoring of electrophysiological signals. This review delves into the challenges associated with the peripheral interface, primarily focusing on monitoring and stimulation. It then provides a summary of common materials and structural design optimizations, discusses technologies for enhancing interface adhesion and surface functionalization, and explores encapsulation methods for implanted devices. Recent advancements in energy supply and the applications of implantable, flexible, and stretchable devices are also comprehensively reviewed, with due consideration given to ethical concerns and signal analysis. The promising directions are finally presented to provide enlightenment for high-performance sensor-tissue interfaces in the future, which will promote profound progress in clinical and human-machine interaction research. Flexible and stretchable devices are at the forefront of healthcare, with the potential to transform the treatment of neuromuscular disorders and enhance human augmentation, blurring the lines between natural and artificial limbs. They represent a promising avenue for the future, with exciting applications in healthcare, science, and technology, promising to bring us closer to the seamless integration of human and machine in the realm of neuromuscular interfaces.

Surface enhanced Raman scattering microtips for microenvironment pH determination of semi-solid preparations.

Semi-solid preparations such as ointments, creams, gels, and pastes are common topical dosage forms with complex compositions and microstructures. pH is a critical quality attribute for semi-solid preparations, affecting properties such as particle size distribution, drug dissociation state, and rheological behavior. Currently, traditional pH electrode methods only provide an "average" pH for large-volume matrices, with low spatial resolution and accuracy. Microenvironment pH detection is crucial for accurately assessing semi-solid preparations. Herein, we developed pH-sensitive surface enhanced Raman scattering (SERS) microtips to achieve localized pH detection in semi-solid preparations. SERS microtips were prepared from glass needles with a tip size of around 1 μm and gold nanoparticles (Au NPs) grown in situ on glass surfaces for SERS enhancement. 4-Mercaptopyridine was selected as a pH sensitive Raman reporter and immobilized on the Au NPs, exhibiting characteristic Raman peak shifts within the pH range of 3-10. The SERS microtips were employed to conduct highly sensitive pH measurements in localized areas of 15 commercial ointments, 8 gels, and 1 laboratory-made ointment, providing higher spatial resolution and microenvironment differentiation compared to pH meters. The SERS microtips were used to monitor pH changes over time in ointment applied to localized wounds on live mice. This work introduces a new tool for pH detection in semi-solid preparations, offering a new method to enhance the prescription process and quality assessment of complex preparations like topical semi-solid preparations.

Dopamine-integrated all-hydrogel multi-electrode arrays for neural activity recording.

Investigation of brain neural circuits is essential for deciphering the diagnostics and therapeutics of neurodegenerative diseases. The main concerns with traditional rigid metal electrodes include intrinsic mechanical mismatch between sensing electrodes and tissues, unavoidable foreign body responses, and inadequate spatiotemporal resolution, resulting in a deficiency of sensing performance. All-hydrogel neural electrodes with multi-electrode arrays (MEAs) suggest a viable way to modulate the trade-off between tissue-mechanical compliance and excellent spatiotemporal recording capacity, but still face the issues of insufficient conductivity and unstable interlayer bonding. Herein, we constructed a four-layer all-hydrogel neural electrode, by sandwiching a conductive hydrogel layer within two encapsulation hydrogel layers, with a shielding hydrogel layer located on top. We introduce a dual-strategy treatment to induce controllable phase separation in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hydrogel, which achieved ultra-high conductivity (up to 4176 S cm-1) comparable to that of metals and precise spatial resolution (∼15 μm) suitable for single neuron recording. In addition, the utilization of polyphenol chemistry mediated adaptive adhesion endowed this neural electrode with flexible and stable interlayer bonding among conductive-encapsulation-shielding layers and the tissue-electrode interface. Consequently, the all-hydrogel neural electrode exhibited a tenfold higher signal-to-noise ratio than a commercial silver electrode, realized the recording of weak neural activity signals within single and multiple neurons in epileptic rats, and applied man-made stimulation to the cerebral cortex of rats during seizures. This work provides a useful tool to understand the development, function and treatment of neurodegenerative diseases.

Bio-inspired carbon electrodes for metal-ion batteries.

Carbon has been widely used as an electrode material in commercial metal-ion batteries (MIBs) because of its desirable electrical, mechanical, and physical properties. Still, traditional carbon electrodes suffer from limited mechanical stability and electrochemical performance in MIBs. Drawing inspiration from biological species, the carbon allotropes, such as fullerenes, carbon nanotubes, and graphene, can be engineered into mechanically robust, highly conductive frameworks with enhanced ion storage and transport capabilities for MIBs. Here, we present an assortment of bio-inspired carbon electrodes that have enhanced the cycling stability, capacity retention, and overall performance of MIBs. In addition, mimicking the structure and functionality of biological systems has led to the development of flexible MIBs whose performance does not degrade even when stretched, bent, or twisted. Finite element analysis (FEA) is a useful guide in identifying such bio-inspired carbon frameworks because it can simulate and analyze potential failure scenarios, such as stress build-up or structural collapse in MIBs. This review highlights through several examples that there is much scope for improving carbon-based electrode materials through bio-inspired designs for practical high-performance MIBs.

A Cu hollow fiber with coaxially grown Bi nanosheet arrays as an integrated gas-penetrable electrode enables high current density and durable formate electrosynthesis.

While high current density formate (HCOO-) electrosynthesis from CO2 reduction has been achieved in a flow cell assembly, the inevitable flooding and salt precipitation of traditional gas-diffusion electrodes (GDEs) severely limit the overall energy efficiency and stability. In this work, an integrated gas-penetrable electrode (GPE) for HCOO- electrosynthesis was developed by coaxially growing vertically aligned high density Bi nanosheet arrays on a porous Cu hollow fiber (Bi NSAs@Cu HF) via controllable galvanic replacement. The interior porous Cu HF serves as a robust gas-penetrable and conductive host for continuously delivering CO2 gas to surface-anchored Bi NSAs, resulting in numerous well-balanced triphase active interfaces for the electrocatalytic CO2 reduction reaction (CO2RR). The most active Bi NSAs@Cu HF GPE exhibits a high HCOO- faradaic efficiency (FEHCOO-) of over 80% in a wide potential window (330 mV) with a linearly increased partial current density (jHCOO-) up to -261.6 mA cm-2 at -1.11 V vs. the reversible hydrogen electrode (RHE). The Bi NSAs@Cu HF GPE also sustains a FEHCOO- of >80% at a high total current density of -300 mA cm-2, corresponding to a jHCOO- of >-240 mA cm-2, for more than 60 h. This work provides new perspectives on designing efficient and durable integrated GPEs for a sustainable CO2RR on a large scale.

Progress in the application of silicon-based anode nanotechnology in lithium batteries

With the development of technology, graphite materials in traditional lithium batteries can no longer meet people’s needs due to their relatively low specific capacity, limited charging and discharging rates, and poor safety. Silicon has a very high theoretical specific capacity, far exceeding traditional graphite negative electrode materials, making silicon nanoparticles an ideal choice for improving the energy density of lithium-ion batteries. In this paper, we first introduce the silicon nanoparticle anode and its preparation methods: mechanical ball milling, and thermal cracking, and introduce the application of binders in it. Secondly, the silicon nanowire anode and the chemical deposition method for its preparation are introduced, and the high-performance silicon nanowire lithium battery of Amprius is introduced. Thirdly, the preparation of silicon thin film anode and two types of composite film was introduced. Finally, the three types of silicon nano anodes are summarized and prospected. This paper has reference significance for the future research of silicon-based lithium-ion batteries.

Enhancing composite electrode performance: insights into interfacial interactions.

Propelled by the widespread adoption of portable electronic devices, electrochemical energy storage systems, particularly lithium-ion batteries (LIBs), have become ubiquitous in modern society. The electrode is the critical battery component, where intricate interactions between the materials govern both the energy output and the overall lifespan of the battery under operational conditions. However, the poor interfacial properties of traditional electrode materials fall short in meeting escalating performance demands. To facilitate the advent of next-generation lithium-ion batteries, attention must be devoted to the interfacial chemistry that dictates and modulates the various dynamic and transport processes across multiple length scales within the composite electrodes. Recent research has concentrated on systematically understanding the properties of distinct electrode components to engineer meticulously tailored electrode formulations. These are geared towards composite electrodes with heightened chemical stability, thermal robustness, enhanced local conductivities, and superior mechanical resilience. This review elucidates the latest advances in understanding the impact of interfacial interactions in achieving high-capacity, high-stability electrodes. Through comprehensive insights into the interfacial interactions between the various electrode components, we can create improved integrated systems that outperform those developed through empirical methods. In light of this, the adoption of a holistic approach to enhance the interactions among electrode materials becomes of paramount importance. This concerted effort ensures the attainment of heightened rate capability, facilitation of lithium-ion transport, and overall system stability throughout the entirety of the cyclic process.

Exploring the Research Progress and Application Prospects of Nanomaterials for Battery Positive and Negative Electrodes

With the development of science and technology, conventional lithium-ion batteries (LIBs) can no longer meet the needs of people. Due to the large particles and small specific surface area of the traditional electrode materials in LIBs, the embedding and dislodging efficiency of lithium ions in the materials is low, thus limiting the energy density of the batteries. During the charging and discharging process, the conventional electrode materials are prone to volume expansion and structural damage, leading to capacity decay and performance degradation. In addition, the ion and electron transport properties of traditional electrode materials are poor, resulting in a limited charging and discharging rate of the battery. The emergence of nanotechnology has opened a new path for the development of battery technology. It not only significantly improves the energy density and power density of LIBs, but also helps to solve the problems of volume expansion and structural damage of LIBs during charging and discharging. More importantly, nanotechnology can improve the safety performance of LIBs. This paper mainly discusses the application of nanotechnology in the electrode materials of LIBs, analyzes the shortcomings of the existing technology, and looks forward to the development of LIBs.

Redox-active electrolytes as a viable approach for the one-step assembly of metal-ion capacitors

The assembly of metal-ion capacitors is a very challenging task; the use of traditional metallic electrodes or sacrificial materials induces technical problems during cell assembly or affects its normal operation. Here, we report an efficient, one-step method for assembling metal-ion capacitors using redox-active electrolytes with thiocyanate-based salts. The addition of a redox-active salt compensates for the charge on the positive electrode while enabling the insertion of metal ions into the structure of the negative electrode. The proposed approach reduces assembly time and cost and results in increased specific energy compared to that from the traditional two-step assembled hybrid systems. Furthermore, we demonstrate that the proposed approach can be successfully implemented for sodium-ion and potassium-ion hybrid capacitors. Our results are supported by operando techniques and can potentially facilitate further research on metal-ion capacitors and applications of these devices.

Enhancing the Electrochemical Performance in Symmetrical Solid Oxide Cells through Nanoengineered Redox-Stable Electrodes with Exsolved Nanoparticles.

Symmetrical solid oxide cells (SSOCs) have recently gained significant attention for their potential in energy conversion due to their simplified cell configuration, cost-effectiveness, and excellent reversibility. However, previous research efforts have mainly focused on improving the electrode performance of perovskite-type electrodes through different doping strategies, neglecting microstructural optimization. This work presents novel approaches for the nanostructural tailoring of (La0.8Sr0.2)0.95Fe1-xTixO3-δ (LSFTx, x = 0.2 and 0.4) electrodes using a single-step spray-pyrolysis deposition process. By incorporating these electrodes into a Ce0.9Gd0.1O1.95 (CGO) porous backbone or employing a nanocomposite architecture with nanoscale particle size, we achieved significant improvements in the polarization resistance (Rp) compared with traditional screen-printed electrodes. To further boost the fuel oxidation performance, a Ni-doping strategy, coupled with meticulous microstructural optimization, was implemented. The exsolution of Ni nanoparticles under reducing conditions resulted in remarkable Rp values as low as 0.34 and 0.11 Ω cm2 in air and wet H2 at 700 °C, respectively. Moreover, an electrolyte-supported cell with symmetrical electrodes demonstrated a stable maximum power density of 617 mW cm-2 at 800 °C. These findings highlight the importance of combining electrode composition optimization with advanced morphology control in the design of highly efficient and durable SSOCs.

Sustainable Laser Induced Supercapacitors from Cork Natural Substrates

A novel type of eco-friendly and cost-effective supercapacitor has been developed by fabricating interdigitated and squared supercapacitors made of porous graphitic carbon electrodes and Polyvinyl alcohol (PVA) electrolyte. The electrodes were fabricated using a simple, fast, and low-cost laser engraving process, using visible irradiation wavelengths (450 nm) and performed under ambient conditions, resulting in highly three-dimensional, electrically conductive, and porous graphitic carbon structures.By adjusting the laser power and wavelength, it was possible to produce electrode materials with highly porous and high surface area morphology, which are promising for electrochemical applications. Spectral investigation using Raman and FTIR spectroscopies confirmed the formation of graphitic carbon structures and the full conversion of the cork precursor under visible laser irradiation.The obtained electrodes exhibited excellent supercapacitive behavior when exposed to a PVA electrolyte, achieving a specific areal capacitance of up to 11.24 mF/cm2 with PVA at 30% laser power. The supercapacitive properties showed excellent stability over time, with no significant loss after 10000 charge/discharge cycles.To evaluate the performance of the new supercapacitors, linear electrodes were used as working electrodes in a three-electrode configuration electrochemical cell. The electrodes showed diffusion-limited electrochemical behavior with fast heterogeneous electron transfer rates (HET), which was superior to that of traditional glassy carbon electrodes.The innovative and efficient electrode fabrication method presented in this study, which utilizes low-cost instrumentation, environmentally friendly fabrication methods, and Earth-abundant precursor materials, shows great promise for producing large-scale "green" electrochemical sensing platforms and devices in the future.

A High-Performance Phenazine-Based Cathode for Aqueous Organic Zinc-Ion Battery

Aqueous Zinc-ion batteries are very appealing for massive energy storage applications due to their inherent safety, low cost, and longevity. Nevertheless, the lack of positive electrode material (cathode) caused by the slow diffusion of Zn2+ inside solid inorganic frameworks is impeding their advancement. Organic electrode materials have recently been endorsed as a less-toxic and environment-benign substitute for traditional inorganic electrode materials. Even though, its performance is hampered by the poor rate capability and limited cycle life caused by cathode material deterioration during Zn2+ insertion/de-insertion. An efficient charge-discharge in aqueous zinc ion batteries, even at high current densities with good capacity retention, is made possible by the stability of aromatic organic heterocyclic cathode materials with the necessary intermolecular spacing. Herein, we describe a strategy to utilize a commercially available redox-active organic molecule (ROM), Phenazine (PNZ) derivative, which can offer efficient and reversible Zn2+ storage due to its high molecular symmetry with low molecular weight. The use of a cation exchange membrane and optimization of volume of the electrolyte and conductive carbon enabled the PNZ electrode to provide a better specific capacity value of 247 mAh g-1 (90% of the theoretical capacity of PNZ) at 1 A g-1 with a good capacity retention of 75 % over 300 cycles. These results indicated that exceptional water insolubility in small organic molecules like PNZ would make them a desirable electrode material for AZIBs. In contrast to conventional design ideas for organic electrode materials such as having a larger molecular weight or adding certain polar functional groups to the organic molecular bulk, our research offered fresh and insightful recommendations for the creation of simpler organic electrodes. Fig. 1. Cyclic performance with charge-discharge plots of PNZ/Katjen black carbon Zinc coin cells with Nafion 212 membrane a) capacity vs. voltage plot b) cycle number vs. capacity plot. Figure 1

In-situ fabrication of Na3V2(PO4)3/C thin-film electrode for high-performance sodium-ion batteries

Compared with the traditional powder electrode, the active material/carbon composite thin-film electrode has many advantages in binder-free, flexible and electrochemical performance. However, typical fabrication methods of film electrodes, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), are complex and costly. Herein, an accessible and economical spin-coating method is proposed to in-situ fabricate Na3V2(PO4)3 film with different thicknesses on graphite discs, whose electrochemical performances are investigated in sodium-ion batteries. The results show that a specific capacity of 167 mA h g−1 at 1 C is obtained in the thinner electrode thanks to the contribution of the graphite substrate. It is also found that the specific capacity of the electrode decreases as the film becomes thicker while the cycling stability and electrochemical kinetics are significantly improved. The capacity retention of 93.8 % is achieved in the thicker electrode after 5000 cycles at 10 C. This work presents a novel idea for designing and building high-performance, economical, and environmentally friendly energy storage devices.

Sulfur poisoning on the La0.75Sr0.25Cr0.5Mn0.5O3-δ-Gd0.1Ce0.9O2-δ fuel electrode for direct electrochemical CO2 reduction in solid oxide electrolysis cells

As a promising energy conversion technology, solid oxide electrolysis cells (SOECs) can efficiently convert CO2 to CO by utilizing renewable energy sources and industrial waste heat. Sulfur poisoning of fuel electrode is a significant drawback to the electrochemical activity and long-term electrolysis performance of SOECs using sulfur-containing fuels. Traditional Ni-based cermet electrodes are susceptible to sulfur poisoning due to the low activation barrier and large enthalpy of the adsorbed sulfur species on the Ni surface. La0.75Sr0.25Cr0.5Mn0.5O3-δ-based materials which exhibit excellent redox stability have been considered as the promising candidates for substitution of Ni-based cermet electrodes. Herein, the sulfur poisoning behavior on the La0.75Sr0.25Cr0.5Mn0.5O3-δ-Gd0.1Ce0.9O2-δ (LSCM-GDC) fuel electrode under CO2–SO2 condition and the mechanism of sulfur poisoning are investigated. The results show that the LSCM-GDC fuel electrode possesses stable electrocatalytic activity as SO2 content up to 10 ppm. With increasing of SO2 content, metallic sulfide, amorphous sulfur and sulfate impurities can be detected on the electrode surface, which decrease the reactive sites and hinder the charge transfer and oxygen ions transport pathway, leading to degradation of the electrolysis performance. The plausible sulfur poisoning mechanism is divided into two categories, namely, thermodynamic and electrochemical processes. For thermodynamic process, SO2 molecules adsorb into oxygen vacancies and couple to coordinated oxygen lattices to form sulfates; for electrochemical process, the formation of amorphous sulfur and metallic sulfide impurities is caused by the binding of SO2 molecules to surface polarons at three phase boundaries under cathodic polarization. This work provides new insights into sulfur poisoning effect on the perovskite oxide electrodes.

In‐situ Polymerized Single Lithium‐ion Conducting Binder as an Integrated Strategy for High Voltage LNMO Electrodes

AbstractHigh voltage spinel LiNi0.5 Mn1.5O4 (LNMO) is a promising material for next generation lithium‐Ion batteries. However, its reactivity near 5 V possess stability and cycling challenges. In this study, a novel integrated approach is employed using a single lithium‐ion conducting polymer binder (SLICPB) to prevent interactions with reactive anions and create a protective layer against electrolyte decomposition. The proposed SLICPB in‐situ polymerization in the LNMO electrodes simplifies the preparation process, reducing costs. SLICPB properties effectively decrease polarization by concentration. For instance, at a discharge capacity of 68 mAh g−1, the voltage hysteresis difference is 0.31 V, enabling higher capacity at 1 C (a 38 % increase) compared to traditional binder electrodes. Notably, this integrated strategy completely replaces the traditional binder without any need for additives, thus avoiding any extra weight in the electrode preparation. Furthermore, SLICPB properties successfully decreasereactivity and diminish the leaching of Mn2+, as evaluated through differential electrochemical mass spectrometry and electron paramagnetic resonance, respectively.