Reference Electrode Research Articles

Wood-Cased Pencil Graphite as Voltammetric Sensor and Sampling by Drone for Field Detection of 2,4,6-Trinitrotoluene Explosive.

This study introduces a novel approach for detecting 2,4,6-trinitrotoluene (TNT) explosives using a pencil-based sensor. The sensor utilizes the circular area of a 3 mm diameter pencil lead enclosed by a wooden shaft as the working electrode. Graphene and silver-silver chloride inks are printed onto transparent sticky tapes, as the counter and reference electrodes, respectively. These tapes are affixed to the pencil body, with copper wires as electrical conductors. Differential pulse adsorptive stripping voltammetry of standard TNT solutions (0.5-30 mg L-1) in 0.5 mol L-1 NaCl reveals two distinct peak signals at -0.46 and -0.64 V, along with a smaller peak at -0.75 V. The identification of TNT in a sample is confirmed by comparing the ratios of these three peak currents with those of standard TNT. The detection of TNT in the field is achieved by employing the pencil sensor in conjunction with drone sampling. The drone is equipped with four sampling devices, each housing a "gel-electrolyte adsorbent" attached to its landing gears. The gel effectively absorbs TNT residues upon landing on suspicious targets. In situ detection with the gel-medium yields a limit of detection (LOD) of 4.8 mg L-1 TNT for standard solutions. Our method demonstrates the efficacy of the pencil sensor for on-site and rapid analysis (2.3 min). Following drone sampling, field detection yields a LOD of 0.026 ng cm-2 TNT. This method proves suitable for remote security screenings in areas of terrorist activities and war zones.

Development of a stable and buffered reference electrode for binary molten chlorides salts

Development of a stable and buffered reference electrode for binary molten chlorides salts

How reference electrodes improve our understanding of degradation processes in half and full cell potassium-ion battery setups

How reference electrodes improve our understanding of degradation processes in half and full cell potassium-ion battery setups

P-1091. Hydrogen peroxide generating electrochemical bandage for the treatment of wound biofilm infections - preliminary demonstration of device safety on healthy human skin

Abstract Background Wound biofilm infections impact ∼2% of the United States and at-risk individuals often have underlying morbidities such as diabetes. Antibiotics and topical approaches like debridement or silver dressings have had limited success, underscoring a need for strategies that efficiently target pathogens in wound beds. Methods We developed a hydrogen peroxide (H2O2) generating electrochemical bandage (e-bandage) composed of carbon fabric electrodes separated by cotton fabric with an Ag/AgCl reference electrode (RE) placed between cotton fabric layers. The e-bandage is controlled by a wearable micropotentiostat (MP); H2O2 is generated by O2 + 2H++ 2e- → H2O2. O2 is dissolved on a primary working electrode with negative polarity compared to the RE while a positively polarized secondary counter electrode generates H+ and e-. The H2O2 e-bandage/MP device has in vitro activity against mono- and dual-species bacterial and fungal biofilms. We showed that the H2O2 e-bandage decreased the burden of methicillin-resistant Staphylococcus aureus and/or Pseudomonas aeruginosa with difficult-to-treat resistance in a murine wound infection model. Given this, we initiated a H2O2 e-bandage safety assessment on healthy human skin. Here, testing of a non-polarized, circular (2 cm diameter) device pre-loaded with biocompatible hydrogel containing 0.9% NaCl is reported. Sterilized e-bandages assessed in a shelf-life study retained activity for two weeks. Adults with intact forearm skin were then recruited to the Clinical Research Trials Unit at the Mayo Clinic. Consented individuals had a non-polarized e-bandage covered by Tegaderm placed on their forearm. A MP enclosed in a biocompatible case was connected to the e-bandage and secured using skin tape. One day later, the device was removed and a follow-up phone call made six days later to assess for adverse effects. Results Three volunteers wearing a non-polarized H2O2 e-bandage experienced no discomfort, irritation, allergic reaction, or skin discoloration after device removal and seven days post device placement. Conclusion These preliminary studies combined with the previously performed murine bacterial biofilms work support further studies of this novel device for treating wound infections caused by antimicrobial resistant pathogens. Disclosures Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, a: See above|MicuRx Pharmaceuticals and BIOFIRE: Grant/Research Support|PhAST, Day Zero Diagnostics, Abbott Laboratories, Sysmex, DEEPULL DIAGNOSTICS, S.L., Netflix, Oxford Nanopore Technologies and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course.: Honoraria

Towards Solid‐State Batteries Using a Calcium Hydridoborate Electrolyte

Solid‐state batteries created from abundant elements, such as calcium, may pave the way for cheaper and safer electrical energy storage. Here we report a new type of solid calcium hydridoborate electrolyte, Ca(BH4)2·2NH2CH3, with a high ionic conductivity of σ(Ca2+) ~ 10‐5 S cm‐1 at T = 70 °C, which is assigned to a relatively open and flexible structure with apolar moieties and weak dihydrogen bonds that facilitate migration of Ca2+ ions in the solid state. The compound display a low electronic conductivity, providing an ionic transport number close to unity (tion = 0.9916). Calcium plating is observed for a Ca|Ca(BH4)2·2NH2CH3|Pt electrochemical cell and the electrodes are investigated using scanning electron microscopy (SEM) combined with energy‐dispersive X‐ray spectroscopy (EDS) that reveal a rugged Ca anode surface owing to the stripping process and the presence of Ca‐containing domains on the Pt working electrode from the plating process. Improved electrochemical reversiblity was achieved in a three‐electrode cell configuration using a CaxSn counter and reference electrode and a Sn working electrode, CaxSn|Ca(BH4)2·2NH2CH3|Sn, providing reversible Ca plating and stripping.

Towards Solid-State Batteries Using a Calcium Hydridoborate Electrolyte.

Solid-state batteries created from abundant elements, such as calcium, may pave the way for cheaper and safer electrical energy storage. Here we report a new type of solid calcium hydridoborate electrolyte, Ca(BH4)2·2NH2CH3, with a high ionic conductivity of σ(Ca2+) ~ 10-5 S cm-1 at T = 70 °C, which is assigned to a relatively open and flexible structure with apolar moieties and weak dihydrogen bonds that facilitate migration of Ca2+ ions in the solid state. The compound display a low electronic conductivity, providing an ionic transport number close to unity (tion = 0.9916). Calcium plating is observed for a Ca|Ca(BH4)2·2NH2CH3|Pt electrochemical cell and the electrodes are investigated using scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS) that reveal a rugged Ca anode surface owing to the stripping process and the presence of Ca-containing domains on the Pt working electrode from the plating process. Improved electrochemical reversiblity was achieved in a three-electrode cell configuration using a CaxSn counter and reference electrode and a Sn working electrode, CaxSn|Ca(BH4)2·2NH2CH3|Sn, providing reversible Ca plating and stripping.

Degree of corrosion and other deterioration effects in highway bridge deck component using non-destructive self potential and vibration testing: case study from SW Nigeria

Recently, the corrosion of steel reinforcement and high vibration intensity have become a major problem in highway bridge stability analysis, and structures that involved reinforcing steel. Therefore, based on suspected human perception, the Ogbese highway bridge stability was investigated using non-destructive half-cell method and vibration measurement. The half-cell measurement was taken at 1 × 1 m grid using Cu/CuSO4 half-cell standard reference electrode, while vibration measurement was taken using vibration meter. The meter is capable of switching acceleration measurement between high (1–4 kHz) and low frequency (10 Hz to 1 kHz) with measurement accuracy of ± 10. The SP result showed that areas with Ecorr greater than −200 mV is 90.8%, Ecorr of −350 mV ≤ Ecorr ≤ −200 mV accounts for 8.5%, and areas with Ecorr less than −350 represents 0.7%. Consequently, the bridge deck is still safe at present. The anomalous zones are represented in each of the bridge span, and mostly within the location of the piers. This implies that there are contributions from the piers/piles reinforcements’ activity. The bridge is also characterized by varying vibration intensity, very high at the northeastern part in terms of acceleration, and displacement than at the southwestern, and middle parts. This is also supported by comparative wide range of values obtained at northeastern part—acceleration, and displacement for the vibration intensities. However, the increasing corrosion activity presently going on may undermine its stability in the long run. Hence a need for thorough maintenance and assessment from time to time.

AuNPs/GO/Pt microneedle electrochemical sensor for in situ monitoring of hydrogen peroxide in tomato stems in response towounding stimulation.

Hydrogen peroxide (H2O2) is a critical signaling molecule with significant roles in various physiological processes in plants. Understanding its regulation through in situ monitoring could offer deeper insights into plant responses and stress mechanisms. In this study, we developed a microneedle electrochemical sensor to monitor H2O2 in situ, offering deeper insights into plant stress responses. The sensor features a platinum wire (100µm diameter) modified with graphene oxide (GO) and gold nanoparticles (AuNPs) as the working electrode, an Ag/AgCl wire (100µm diameter) as the reference electrode, and an untreated platinum wire (100µm diameter) as the counter electrode. This innovative design enhances sensitivity and selectivity through the high catalytic activity of AuNPs, increased surface area from GO, and the superior conductivity of platinum. Operating at a low potential of -0.2V to minimize interference, the sensor detects H2O2 concentrations from 10 to 1000µM with high accuracy. In situ monitoring of H2O2 dynamics in tomato stems under the wounding stimulation reveals that H2O2 concentration increases as the sensor approaches the wound site, indicating localized production and transport of H2O2. This approach not only improves H2O2 monitoring in plant systems but also paves the way for exploring its generation, transport, and elimination mechanisms.

Fast Charging of Silicon Anode-Based Lithium-Ion Batteries at the Pouch Cell Level

Abstract Silicon (Si) is an attractive anode material for next-generation lithium-ion batteries (LIBs) because of its high theoretical capacity and natural abundance. Therefore, its physical and energy storage properties, especially achieving high specific capacity and cyclability, have been studied extensively. However, there is a lack of reports on the proper fast charging of Si-based LIBs. Herein, we developed an anode by physically mixing Si nanoparticles with carbon nanotubes and assembled a three-electrode pouch cell by pairing the developed anode with a lithium nickel manganese cobalt oxide cathode and an extra reference electrode. The reference electrode was crucial in developing a fast-charging protocol (FCP) that not only fast-charged the cell but also prevented lithium plating, which is essential for extending the cycle life of LIBs. The FCP achieved 10–80% and 0–80% states of charge in 14.5 and 20.5 minutes, respectively, at room temperature. The FCP achieved ~55% capacity retention (616 mAh g-1) after 500 fast-charging cycles, indicating excellent cycle stability and good battery health. This work presents FCP and its performance data from Si-based LIBs to the battery community, which can be crucial to exploring the fastest possible FCP for next-generation high-energy-density LIBs.

Emerging evidence on the effects of electrode arrangements and other parameters on the application of transcutaneous spinal direct current stimulation.

Transcutaneous spinal direct current stimulation (TSDCS) has the potential to modulate spinal circuits and induce functional changes in humans. Nevertheless, differences across studies on basic parameters used and obtained metrics represent a confounding factor. Computer simulations are instrumental in improving the application of the TSDCS technique. Their findings allow a better interpretation of the tissue conductivities heterogeneity. Emerging findings indicate the electric field is maximal in the segments located between the electrodes and that factors such as the depth of the targeted area, and location of the electrodes on low conductive points, such as the spinous processes, may impact the electric field generated in the spinal cord, with consequences for thoracic versus lumbar or cervical applications. Recently, growing attention has been directed toward the importance of the TSDCS reference electrode's position and its influence on the current field properties at the targeted site. This review highlights the influence of dosage, polarity, and electrode position on the variety of TSDCS results in healthy and some clinical populations. Based on the available evidence, we suggest that although the current dosage appears to have a negligible effect, the variety of electrode montages and configurations of TSDCS can significantly impact the electric field distributions and potentially explain the conflicting results of experimental studies. Future human trials should systematically and thoughtfully evaluate the location of TSDCS electrodes based on the targeted neural structures.

A Study of the Corrosion Behavior of AHSS Complex-Phase CP 780 Employing an Electrochemical Noise Technique Analyzed by Different Methods

The automotive industry employs structural steels with E-coats to reduce weight and increase the corrosion resistance of chassis, reducing CO2 emissions. Due to their mechanical properties, part of the chassis is a composite of advanced high-strength steels (AHSS). AHSSs are coated by conversion methods such as phosphate to increase epoxy coating adherence and corrosion resistance. The main point of this research is to characterize an AHSS complex-phase (CP) 780 in blank, with a phosphate coating and an E-coat organic coating using electrochemical noise, employing time-domain, frequency-domain, time–frequency-domain, and chaotic system methods to determine the type and corrosion kinetics of each system. The electrochemical noise technique was made with a conventional three-electrode cell, using a saturated calomel as a reference electrode. Data were recorded at 1024 s, at 1 data per second in a 3.5 wt. % NaCl electrolyte, according to ASTM G199-09. The results show how AHSS CP 780 presented uniform corrosion, similarly to the phosphate sample; however, the E-coat presented a trend of a localized process when analyzed by Wavelets transform. On the other hand, corrosion resistance increased for the E-coat sample, with values of 2.58 × 106 Ω·cm2. According to the results of the research, all the samples are susceptible to present localized corrosion.

Identification and analysis of reference-independent movement event-related desynchronization

Characterization of the electroencephalography (EEG) signals related to motor activity, such as alpha- and beta-band motor event-related desynchronizations (ERDs), is essential for Brain Computer Interface (BCI) development. Determining the best electrode combination to detect the ERD is crucial for the success of the BCI. Considering that the EEG signals are bipolar, this involves the choice of the main and reference electrodes. So far, no strategy to guarantee signals free of the activity from the reference electrode has achieved consensus among the scientific community. Therefore, mapping the ERD in terms of the spatial distribution of the main and reference electrodes can provide additional perspectives for the BCI field. The goal of this work is to identify subject-specific channels where ERD is temporally coupled to the initiation of an upper-limb motor task. We defined a criterion to determine the presence of the ERD linked to the movement onset and searched, separately for each subject, for the single channel with the most prominent ERD. The search was conducted over all available channels composed by a pair of electrodes, and the selected signals were analyzed according to their temporal and spatial characteristics. We found that alpha- and beta-band ERD temporarily linked to movement onset can be detected in atypical channels (pairs of electrodes) across the scalp. The selected channels were different across subjects. Four ERD temporal patterns were observed in terms of the initiation instant of the ERD. These patterns revealed that the M1 cortex seems to be related to later ERDs. Moreover, they were also associated to different cortical processes related to the motor task. To the best of our knowledge, this is the first time these findings are reported. Aiming at BCI development, further experiments with more subjects and with motor-imagery tasks are desirable for more robustness and applicability of these findings.

Biological and Mechanical Limitations for Chronic Fast‐Scan Cyclic Voltammetry Sensor Design

AbstractFast‐scan cyclic voltammetry (FSCV) is a popular approach for real‐time neurochemical sensing. Using a carbon‐fiber microelectrode (CFME), sensitive neurochemical sensing can be achieved in the acute setting with sub‐second resolution for monoamine neurotransmitters. However, to study neuropsychiatric conditions and neurological functions, it is often of interest to perform longitudinal monitoring of neurotransmitters over chronic timepoints. Despite notable successes, there remains substantial room for improvement in chronic neurochemical sensing performance. Electrode fouling and cellular encapsulation that can occur following surgical implantation can lead to diminished sensor performance over time. Additionally, working and reference electrodes can suffer from etching and polarization that can hinder their longevity and stability. Here, this work reviews current challenges facing chronic neurochemical sensors and discusses state‐of‐the‐art advancements in electrode material and device design choices. This work covers how the biological environment can negatively affect sensing performance and how device design can mitigate these effects. This work also provides examples of state‐of‐the‐art electrode technologies that have been developed to improve chronic neurochemical sensing. Improvements in FSCV as a tool for chronic neurotransmitter sensing will open new opportunities to study neurodegenerative and neuropsychiatric diseases, develop feedback systems for neuromodulation, and explore the neurochemical underpinnings of normal brain function and behavior.

Enhanced bioelectrochemical degradation of Thiabendazole using biostimulated Tunisian hypersaline sediments: kinetics, efficiency, and microbial community shifts.

Thiabendazole (TBZ), a recalcitrant fungicide, is frequently applied in postharvest fruit treatment and generates significant volumes of industrial wastewater (WW) that conventional treatment plants cannot handle. This explores a bioelectrochemical system (BES) for TBZ degradation using Tunisian hypersaline sediments (THSs) as inoculum. Four sets of BES, along with biological controls, were tested using THS subjected to different levels of TBZ biostimulation. Sediments underwent one, two, or three biostimulation phases with increasing TBZ concentrations (0, 10, 100, and 300 mg kg-1). Potentiostatic control was applied to BES, polarized at 0.1 V vs. saturated calomel reference electrode (SCE), with a carbon felt working electrode (72 cm2 L-1) and maintained at 25°C. While current production was very low, sediments biostimulated with 100 mg kg-1 kg TBZ produced the highest current density (3.2 mA m-2), a 5-fold increase over untreated sediments (0.6 mA m-2). GC-FID analysis showed >99% TBZ degradation in all reactors. The TBZ half-elimination time from 27 days with biological treatments to 19 days in BES and further to 6 days following biostimulation. Bacterial analysis revealed a substantial microbial community shift after biostimulation, with a reduction in Bacillota (-64%) and an increase in Proteobacteria (+62%), dominated by Pseudomonas (45%) and Marinobacter (16%). These findings provide insight into the selective potential of biostimulation cycles to enhance microbial community composition and improve BES performance for TBZ wastewater treatment.

Novel carbon paste sensor modified with MWCNT and Ca-doped ZnO nanocomposite for therapeutic monitoring of Favipiravir in COVID-19 patients

Favipiravir (FAV) is a prodrug with a proven antiviral efficacy against coronavirus 2. Close therapeutic monitoring of FAV is crucial for COVID-19 patients due to its variable dosing, complex pharmacokinetics, and notable drug interactions. This study presents a novel, selective electrochemical sensor for FAV detection, using a carbon paste electrode (CPE) modified with multi-walled carbon nanotubes (MWCNTs) and calcium-doped ZnO nanoparticles (Ca-ZnO NPs). Characterization of the Ca-ZnO NPs was performed using Fourier-transform infrared spectroscopy (FT-IR), field emission-scanning electron microscope (FE-SEM), and X-ray photoelectron spectroscopy (XPS). Several operational parameters were optimized, including carbon paste composition, buffer selection, pH, and electrochemical waveform settings. Under optimized conditions, an oxidation signal of FAV was identified at approximately + 1.22 V versus an Ag/AgCl reference electrode in Britton-Robinson buffer (BRB) at pH 4.0. Differential pulse voltammetry (DPV) facilitated the detection of FAV across a wide dynamic concentration range of 0.6–100.0 µM, with detection and quantification limits of 0.17 and 0.51 µM, respectively. The developed method demonstrated high selectivity towards FAV, effectively distinguishing it from its acidic degradation product (ADP), qualifying it as a stability-indicating assay. Evaluations using the GAPI, AGREE, and RGB 12 metrics confirmed alignment with green and white analytical chemistry principles. Furthermore, this method was successfully applied to quantify FAV in human plasma, making it suitable for therapeutic drug monitoring (TDM) in COVID-19 patients.

Adding colour to ion-selective membranes.

An idea of using ion-exchanger salt containing optically active cations to prepare ion-selective membranes is proposed. Although the presence of an ion-exchanger in the composition of neutral ionophore based sensors is necessary, the choice of available salts for cation-selective sensors preparation, is usually limited to sodium or potassium compounds. In this work we propose application of an alternative salt, using a cation optically active both in absorption and emission mode as a mobile one. Thus, coloured ion-selective membranes can be obtained. This in turn opens new possibilities of monitoring the state of the receptor layer as well as allows direct analytical application of ion-selective membranes in simple optical mode with all benefits related to eliminating the necessity of using reference electrodes. As a model system Nile blue derivative of tetrakis[3,5-bis(trifluoromethyl)phenyl]borate ion-exchanger was prepared and used to obtain potassium or calcium selective sensors. Selective exchange of ions between the membrane and solution, leading to an increase in optical signal of the solution, can be used to quantify the presence of analyte ions. Thus the sensor pretreatment process is becoming a source of analytical information. The applicability of this approach was verified in determining the presence of potassium ions in the vast majority of interfering ions, e.g. present as impurities in the reagent grade calcium chloride. The resulting potassium ions contents was well comparable with values obtained in course of ICP-MS approach.

A comb-shaped microfluidic aptasensor for rapid and sensitive on-site simultaneous detection of aflatoxin B1 and deoxynivalenol.

Mycotoxins are widely found as co-contaminants in agricultural products and their derivatives. However, on-site monitoring of multiple mycotoxins remains a significant challenge. We developed an electrochemical aptasensor integrating microelectrodes and microfluidics for simultaneous aflatoxin B1 (AFB1) and deoxynivalenol (DON) detection. Its sensing interface had dual working electrodes modified with two specific aptamers, sharing a counter and a reference electrode. The microfluidic chip's comb-shaped structure enhanced aptamer-target binding. Using a buffer with redox probes for electrochemical detection, we achieve label-free quantitative detection of both toxins within 20min. The sensor had detection limits of 7.74pg/mL for AFB1 and 0.172ng/mL for DON, with linear detection ranges of 0.03-300ng/mL and 0.3-3000ng/mL respectively. It exhibited excellent specificity, repeatability and stability. In summary, this electrochemical aptasensor enables rapid and sensitive on-site detection of AFB1 and DON, safeguarding food safety during grain storage for early monitoring and prevention.

Development of 3D-printed conducting microneedle-based electrochemical point-of-care device for transdermal sensing of chlorpromazine.

Despite the various benefits of chlorpromazine, its misuse and overdose may lead to severe side effects, therefore, creating a user-friendly point-of-care device for monitoring the levels of chlorpromazine drug to manage the potential side effects and ensure the effective and safe use of the medication is highly desired. In this report, we have demonstrated a simple and scalable manufacturing process for the development of a 3D-printed conducting microneedle array-based electrochemical point-of-care device for the minimally invasive sensing of chlorpromazine. We used an inkjet printer to print the carbon and silver ink onto a customized 3D-printed ultrasharp microneedle array for the preparation of counter, working, and reference electrodes. After physical characterization and electrochemical parameter optimization, the developed microneedle array-based three-electrode system was explored for the detection of chlorpromazine. The analytical results showed high sensitivity and selectivity toward chlorpromazine with a good linearity range from 5-120 μM and a low detection limit (0.09 μM). The proof-of-concept study results obtained from the skin-mimicking model indicated that the developed conductive microneedle array-based sensor can easily monitor the micromolar levels of chlorpromazine in artificial interstitial fluid; this type of system can be further explored for the development of other minimally invasive electrochemical biosensors.

A Versatile Reference Electrode for Lithium Ion Battery Use

A lithium-ion battery reference electrode applicable to both laboratory and onboard vehicle use provides a high level of understanding of electrochemical processes within a cell and enables highly sophisticated, real-time electrode control that maximizes cell utilization, life, safety, and overall value. The approach taken for this work is to combine the chemical stability of LFP with miniaturization in the form of an extremely thin and porous active layer, and optimal placement within the cell by coating the active reference layer on an additional layer or separator that is inserted between the anode and cathode in the cell. This thin, porous, separator-mounted reference has no effect on the cell beyond that of an extra layer of separator. Extraction of electrode kinetic parameters and electrode-level control of DC fast charge are shown for NCMA/Graphite cells in two different formats to demonstrate the simplicity, fidelity, and robustness of the reference electrode design.

Understanding delamination behavior of air electrode in solid oxide electrolysis cells through in situ monitoring of internal oxygen partial pressure

In this study, we monitored the development of internal pO2 in solid oxide electrolysis cells (SOECs) in situ using an embedded probe and a reference electrode. Three types of air electrode cells were compared: LSM (La0.8Sr0.2MnO3−δ) + YSZ (Y0.08Zr0.92O2−δ), LSCF (La0.6Sr0.4Co0.2Fe0.8O3−δ) + GDC (Gd-doped ceria) and LSM + GdCeScSZ ((Gd2O3)0.005(CeO2)0.005(Sc2O3)0.1(ZrO2)0.89). The rate of pO2 increase with the increase in current density was highest in the LSM + YSZ cell, reaching ∼32201 atm at 0.6 A cm−2, resulting in air electrode delamination and intergranular fractures. This physically developed delamination with high pO2 is akin to catastrophic failure, accelerating degradation. The LSCF + GDC cells exhibited a maximum pO2 of ∼12.25 atm and operated stably without increasing pO2 or delamination. In the LSM + GdCeScSZ cells, internal pO2 was substantially suppressed to ∼10−3 atm, with a degradation rate comparable to that of the LSCF + GDC cell. However, the air electrode delaminated without intergranular fractures. This chemically developed delamination without high internal pO2 does not significantly accelerate degradation. These results indicate that the delamination mechanism may vary even with the same LSM electrode, depending on its ionic conduction characteristics.