High Conductivity Research Articles

Static and Dynamic Properties Investigation of Modified Polyethersulfone Membrane for Direct Methanol Fuel Cell Applications

The present study's main focus is understanding the impact of modification, especially through phosphoric acid and acetic acid, on polyethersulfone (PES) membranes for direct methanol fuel cell application, as sulfonation is the preferred modification method. The cross-linking introduces the sulfonate, phosphonate, and carboxylate group in the polymer matrix, while the membrane's semi-crystalline nature and homogeneous surface are confirmed through instrumental analysis. The high ion exchange capacity and water retention capacity of the phosphoric acid cross-linked PES membrane (PPES-2) reveal its potentiality. The impact of different hydration levels and temperatures on proton conductivity indicates that based on the operating conditions, the cross-linked membrane can be used, such as at high temperatures and 50% hydration level, the PPES-2 membrane shows high proton conductivity as well as has low methanol crossover due to the presence of hydroxyl group. At the same time, the acetic acid-treated PES (CPES-2) membrane shows high proton conductivity at 50% hydration level and low temperature. The same is confirmed through molecular dynamic simulation by understanding their dynamic and static properties. The PPES-2 membrane shows maximum power density (0.34 Wcm-2). In conclusion, the study indicates that PES modification can be done through phosphorylation and carboxylation, apart from sulfonation.

A Flexible Nylon-Spandex Fabric-Supported PVA/PANI Hydrogel Sensor with High Strength and Conductivity

A Flexible Nylon-Spandex Fabric-Supported PVA/PANI Hydrogel Sensor with High Strength and Conductivity

A Highly Stable and Non-Flammable Deep Eutectic Electrolyte for High-Performance Lithium Metal Batteries.

Deep eutectic electrolytes (DEEs) are regarded as one of the next-generation electrolytes to promote the development of lithium metal batteries (LMBs) due to their unparalleled advantages compared to both liquid electrolytes and solid electrolytes. However, its application in LMBs is limited by electrode interface compatibility. Here, we introduce a novel solid dimethylmalononitrile (DMMN)-based DEE induced by N coordination to dissociate LiTFSI. We confirmed that the DMMN molecule can promote the dissociation of LiTFSI by the interaction between the N atom and Li+, and form the hydrogen bond with TFSI- anion, which can promote the dissociation of LiTFSI to form DEE. More importantly, due to the absence of active α-hydrogen, DMMN exhibits greatly enhanced reduction stability with Li metal, resulting in favorable electrode/electrolyte interface compatibility. Polymer electrolytes based on this DEE exhibit high ionic conductivity (0.67 mS cm-1 at 25 ℃), high oxidation voltage (5.0 V vs. Li+/Li), favorable interfacial stability and nonflammability. Li‖LFP and Li‖NCM811 full batteries utilizing this DEE polymer electrolyte exhibit excellent long-term cycling stability and excellent rate performance at high rates. Therefore, the new DMMN-based DEE overcomes the limitations of traditional electrolytes in electrode interface compatibility and opens new possibilities for improving the performance of LMBs.

Highly acid-stable high-temperature proton exchange membrane: Azide-based polymeric ionic liquids for the enhancement of amino-polybenzimidazole

Polybenzimidazole (PBI) is commonly used for high-temperature proton exchange membranes. However, it is undeniably challenging for phosphoric acid (PA)-doped PBI membranes to have both high proton conductivity and excellent long-term stability. In this study, a series of polymer ionic liquid composite PBI membranes were fabricated. These membranes are made using two azide-functional ionic liquids and amino-polybenzimidazole, adjusting the amount of the two ionic liquids. The ionic pairs offered by the ionic liquids positively impact the transportation of protons and the stability of PA through the replacement of anions. It is noteworthy that crosslinked amino-polybenzimidazole membranes containing functional polymeric ionic liquids have proton conductivity of up to 131.7 mS cm−1 at 180 °C, and the PA retention after 240 h at 160 °C under humidity-free conditions is 86.5 %. In addition, the membrane is used in membrane electrodes with hydrogen and oxygen at the anode and cathode, respectively, exhibiting a peak power density of 694.6 mW cm−2 at 160 °C. And the voltage decay rate is 0.28 mV h−1 after long-term test. The findings indicate that membranes made of functional polymeric ionic liquids crosslinked with amino-polybenzimidazoleprovide a new strategy to enhance fuel cell durability.

Organometallic Ionic Plastic Crystals Incorporating Cationic Half-Sandwich Complexes.

Ionic plastic crystals (IPCs), characterized by nearly spherical molecular ions, exhibit remarkable solid-state characteristics including high ionic conductivity. However, most IPCs are organic onium salts. Incorporating organometallic half-sandwich complexes into IPCs is challenging owing to their low-symmetry structures. This paper introduces a novel series of IPCs composed of salts derived from half-sandwich organometallic complexes. We synthesized five salts of [Ru(Cp)(tmeda)(CO)]X (tmeda = N,N,N',N'-tetramethyl-1,2-ethanediamine, X = anion) with different anions and examined their phase behavior, crystal structures, and molecular motion in the solid-state. Salts featuring the CPFSA (= 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonimide), B(CN)4-, and FSA- (= (FSO2)2N-) anions underwent phase transitions to an IPC phase with a CsCl-type structure in the temperature range of 327-364 K. Employing smaller anions led to an increase in the transition temperature. In each salt, the coordination number, representing the number of anions surrounding one cation, remained eight in IPC and low-temperature phases. However, salts containing smaller anions (CF3BF3- and PF6-) displayed a rotator phase rather than the IPC phase. In these cases, the coordination numbers were six at low temperatures.

Effect of graphene arrangement on the thermal conductivity of graphene/polymer nanocomposites

ABSTRACT Due to its high thermal conductivity (up to 5300 W/mK), graphene is considered an ideal filler for composites with a polymer matrix to form a thermal interface material with excellent thermal performance. The thermal conductivity of graphene/polymer nanocomposites can be effectively improved by increasing the aspect ratio of graphene, simultaneously increasing the lateral size and thickness of graphene at a constant aspect ratio or changing the ordered orientation of graphene nanosheets (GNSs) filled in the polymer matrix. Experimental results have shown that the ultrahigh thermal conductivity of the composites can be achieved in the in-plane direction due to the minimum interface thermal resistance along this direction. To detect the arrangement structure of GNSs on the thermal conductivity of the composites, this paper obtained the expressions of the effective thermal conductivity for anisotropic GNSs/polymer composites based on the multiple-scattering theory, where the effect of the number of GNSs layers on the interface thermal resistance and thermal conductivity of GNSs is considered. The numerical results show that the composites parallel to the aligned direction of GNSs have greater thermal conductivity than those perpendicular to it. The ordered orientation of GNSs can effectively improve the thermal conductivity for GNSs/polymer nanocomposites.

Flexible LaNiO3 film with both high electrical conductivity and mechanical robustness

Lanthanum nickel oxide (LaNiO3, LNO) films exhibit excellent electrical conductivity but poor mechanical properties, considerably limiting their further development in the field of flexible electronics. In this study, flexible LNO thin films of different thicknesses were fabricated on a unique two-dimensional (2D) mica platform using a simple metal organic deposition technique. The obtained LNO films exhibited a pseudocubic phase without impurities. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterisations proved that the films were well-crystallised, dense, and flat, with controllable thickness. In addition, the flexible LNO/mica element possesses low resistivity (5 × 10−4 Ω cm), translucency, and good bending resistance. The electrical resistivity can remain stable under various bending radii (r = 10∼2 mm), thousands of bending cycles, and a wide temperature range (28–200 °C), demonstrating good durability, mechanical stability and temperature resistance. Furthermore, a ferroelectric BiFeO3 film was constructed based on the obtained conductive LNO electrode, which exhibited typical ferroelectric characteristics. This excellent performance suggests that the flexible LNO electrode is promising for flexible electronic applications.

Iron-based metal-organic framework/graphene oxide composite electrodes for efficient flow-injection amperometric detection of dexamethasone.

A highly stable flow-injection amperometric sensor for dexamethasone (DEX) was developed using a pencil graphite electrode (PGE) modified with Fe-based metal organic frameworks, MIL-100(Fe) and graphene oxide composite materials (MIL-100(Fe)/GO). Scanning electron microscopy and energy-dispersive X-ray spectroscopy, transmission electron microscopy, powder X-ray diffraction, and Fourier-transform infrared spectroscopy were used to characterize the MIL-100(Fe) composites. The MIL-100(Fe)/GO-modified PGE (denoted MIL-100(Fe)/GO/PGE) was further electrochemically characterized using cyclic voltammetry. As an electrode material, MIL-100(Fe) is a sensing element that undergoes oxidation from Fe(ii)-MOF to Fe(iii)-MOF, and GO possesses high conductivity and a large surface area, which exhibits high absorbability. In the presence of DEX, Fe(iii) is reduced, which accelerates electron transfer at the electrode interface. Therefore, DEX can be quantitatively detected by analyzing the anodic current of MIL-100(Fe). When coupled with amperometric flow injection analysis, excellent performance can be obtained even when a low detection potential is applied (+0.10 V vs. Ag/AgCl). The concentration was linear in the range 0.10-5.0 μM and 0.010-5.0 mM with LOD of 0.030 μM based on 3(sd/slope). The modified electrode also exhibited a remarkably stable response under optimized conditions, and up to 55 injections can be used per electrode. The sensor exhibits high repeatability, reproducibility, and anti-interference properties when used for DEX detection. The effective determination of dexamethasone in real pharmaceutical and cosmetic samples demonstrated the feasibility of the electrochemical sensor, and the results were in good agreement with those obtained from the HPLC-DAD analysis. Acceptable percentage recoveries from the spiked pharmaceutical and cosmetic samples were obtained, ranging from 93-111% for this new method compared with 84-107% for the HPLC-DAD standard method.

Synthesis of nano-diamond film on GaN surface with low thermal boundary resistance and high thermal conductivity

Joule self-heating is the main obstacle limiting the performance of GaN power devices. A nano-diamond (NCD) film for near-junction heat transfer has been approved as an effective approach to overcome this issue. In the present study, we developed a scheme to deposit a smooth NCD film with high thermal conductivity (TC) over the surface of GaN. First, a 10-nm Si3N4 was deposited as the protective layer of GaN, followed by electrostatic seeding to improve nucleation density and particle distribution uniformity. Second, argon and gradient methane gas were introduced to prepare the NCD film based on nucleation and the growth period. The resulting thickness of the NCD film was 150 nm with a roughness of about 20 nm. The thermal boundary resistance (TBReff) between GaN and NCD film was only 12.8 ± 0.64 m2K/GW, whereas the TC of the NCD film was 200 ± 40 W m−1 K−1, which was similar to the theoretical prediction. Thus, it could be inferred that the high crystallinity of the NCD film contributes to the low TBReff and high TC through the whole NCD layer.

A Soft-Fiber Bioelectronic Device with Axon-Like Architecture Enables Reliable Neural Recording In Vivo under Vigorous Activities.

Implantable neural devices that record neurons in various states, including static states, light activities such as walking, and vigorous activities such as running, offer opportunities for understanding brain functions and dysfunctions. However, recording neurons under vigorous activities remains a long-standing challenge because it leads to intense brain deformation. Thus, three key requirements are needed simultaneously for neural devices, that is, low modulus, low specific interfacial impedance, and high electrical conductivity, to realize stable device/brain interfaces and high-quality transmission of neural signals. However, they always contradict each other in current material strategies. Here, a soft fiber neural device capable of stably tracking individual neurons in the deep brain of medium-sized animals under vigorous activity is reported. Inspired by the axon architecture, this fiber neural device is constructed with a conductive gel fiber possessing a network-in-liquid structure using conjugated polymers and liquid matrices and then insulated with soft fluorine rubber. This strategy reconciles the contradictions and simultaneously confers the fiber neural device with low modulus (300kPa), low specific impedance (579kΩµm2), and high electrical conductivity (32700Sm-1) - ≈1-3 times higher than hydrogels. Stable single-unit spike tracking in running cats, which promises new opportunities for neuroscience is demonstrated.

High stretchable and self-adhesive multifunctional hydrogel for wearable and flexible sensors

Ionic conductive hydrogel has recently garnered significant research attention due to its potential applications in the field of wearable and flexible electronics. Nonetheless, the integration of multifunctional and synergistic advantages, including reliable electronic properties, high swelling capacity, exceptional mechanical characteristics, and self-adhesive properties, presents an ongoing challenge. In this study, we have developed an ionic conductive hydrogel through the co-polymerization of 4-Acryloylmorpholine (ACMO) and sodium acrylate using UV curing technology. The hydrogel exhibits excellent mechanical properties, high conductivity, superior swelling capacity, and remarkable self-adhesive attributes. The hydrogel serves as a highly sensitive strain sensor, enabling precise monitoring of both substantial and subtle human motions. Furthermore, the hydrogel demonstrates the capability to adhere to human skin, functioning as a human-machine interface for the detection of physiological signals, including electromyogram (EMG) signals, with low interfacial impedance. This work is anticipated to yield a new class of stretchable and conductive materials with diverse potential applications, ranging from flexible sensors and wearable bio-electronics to contributions in the field of artificial intelligence.

Constructing multi-layer heterogeneous interfaces in liquid metal graphite hybrid powder: Towards microwave absorption enhancement

Carbon based materials are widely used in the preparation of microwave absorption materials due to their low density, high attenuation loss and large specific surface area. However, their high conductivity usually leads to high reflection loss. In this study, multi-layer heterogeneous interfaces were constructed in liquid metal graphite hybrid powder to reduce reflection loss and enhance microwave absorption performance. Gallium oxide (Ga2O3) layer was formed in Ga coated graphite powder to improve impedance matching and attenuation constant via an annealing treatment. Specifically, the hybrid particles with 50 wt% Ga and being annealed at 120 °C for 2 h have a minimum reflection loss (RLmin) value of −42.68 dB and a maximum effective absorption bandwidth (EAB) of 4.11 GHz at a thickness of 3.3 mm. The hybrid particles not only have multi-layer structures with different electrical conductivity, but also form heterojunctions between different interfaces, which can further enhance dipole and interfacial polarization.

β-Cyclodextrin-enabled, densely cross-linked anion-exchange membranes for fuel cell applications

Polyarylpiperidinium anion exchange membranes (AEMs) have been widely studied in anion exchange membrane fuel cells and alkaline electrolyzed water due to their excellent alkali resistance stability. In this work, we report the design and fabrication of poly(p-triphenylene-piperidinyl) (PTP) AEMs quaternized and cross-linked by bromo-β-cyclodextrin (β-CD-Br7). In this type of membranes, the densely cross-linked and quaternized sites derived from β-CD-Br7 can help to construct continuous ion transport channels to facilitate ion conduction. Although the ion exchange capacity (IEC) tended to decrease with increasing cross-linking degree, the qPTP-CD5 membrane with 5 % cross-linking (IEC = 2.3 mmol g−1) produced the most significant microphase separation and the highest conductivity (125.6 mS cm−1 at 80 °C). The membrane also exhibited impressive alkaline stability, with 94.6 % conductivity retention in 1 M NaOH at 80 °C after 1000 h and 90.7 % conductivity retention after 1500 h. Finally, the peak power density of the fuel cell assembled with qPTP-CD5 membranes was 1.216 W cm−2 at 80 °C and there was no significant voltage degradation when operated at 200 mA cm−2 current density for 40 h. This work demonstrates that β-CD can function as a good “platform” for simultaneous cross-linking and quaternization to fabricate high performance AEM.

Interfacial Stabilization by Prelithiated Trithiocyanuric Acid as an Organic Additive in Sulfide‐Based All‐Solid‐State Lithium Metal Batteries

AbstractSulfide‐based all‐solid‐state battery (ASSB) with a lithium metal anode (LMA) is a promising candidate to surpass conventional Li‐ion batteries owing to their inherent safety against fire hazards and potential to achieve a higher energy density. However, the narrow electrochemical stability window and chemical reactivity of the sulfide solid electrolyte towards the LMA results in interfacial degradation and poor electrochemical performance. In this direction, we introduce an organic additive approach, that is the mixing of prelithiated trithiocyanuric acid, Li3TCA, with Li6PS5Cl, to establish a stable interface while preserving high ionic conductivity. Including 2.5 wt % Li3TCA alleviates the decomposition of the electrolyte on the lithium metal interface, decreasing the Li2S content in the solid‐electrolyte interface (SEI) thus forming a more stable interface. In Li|Li symmetric cells, this strategy enables a rise in the critical current density from 1.0 to 1.9 mA cm−2 and stable cycling for over 750 hours at a high current density of 1.0 mA cm−2. This approach also enables Li|NbO‐NCM811 full cell to operate more than 500 cycles at 0.3 C.

Enhancing the tribological performance of composite electrostatic spray lubrication using blended plant oils

As a sustainable machining lubrication technique, composite electrostatic spray lubrication (CESL) adopts a high-voltage electric field to atomize oils (external fluid) and water (internal fluid) into oils-on-water (OoW). Although castor oil shows excellent lubrication properties, its high viscosity and low electrical conductivity lower the atomization performance and impede the attainment of ideal tribological performance in CESL applications. Blending castor oil with other plant oils is anticipated to effectively resolve this matter through the improvement in chargeability and fluidity. Nevertheless, no research work on the use of blended plant oils to enhance the CESL performance has been conducted. This study employed sliding friction tests between carbide slices and steel discs to explore the tribological performance of CESL under various blended types, blended ratios, external/internal flow rates, and voltages. The physical properties and fatty acid compositions of blended plant oils, as well as the charging and electrowetting capabilities of OoW, were examined to study their impacts on the tribological performances of CESL. The research findings demonstrated that the application of blended plant oils improved the tribological performance of castor oil-based CESL. The optimal blended type, blended ratio, external/internal flow rate, and voltage were respectively castor oil blended with soybean oil, 1:2, 8/4 ml/h, and −7.5 kV. Compared to the CESL employing castor oil and commercial plant oil, the blended plant oil-based CESL with optimized parameters led to reductions of 89.99–96.40 % in the coefficient of friction, 93.33–97.33 % in the carbide wear loss, and 70.00–73.80 % in the depth of disc wear marks, respectively. The research outcomes are helpful to understand the tribological behavior of blended plant oil-based CESL, thus providing a reference for its practical application.

Interfacial Stabilization by Prelithiated Trithiocyanuric Acid as an Organic Additive in Sulfide-Based All-Solid-State Lithium Metal Batteries.

Sulfide-based all-solid-state battery (ASSB) with a lithium metal anode (LMA) is a promising candidate to surpass conventional Li-ion batteries owing to their inherent safety against fire hazards and potential to achieve a higher energy density. However, the narrow electrochemical stability window and chemical reactivity of the sulfide solid electrolyte towards the LMA results in interfacial degradation and poor electrochemical performance. In this direction, we introduce an organic additive approach, that is the mixing of prelithiated trithiocyanuric acid, Li3TCA, with Li6PS5Cl, to establish a stable interface while preserving high ionic conductivity. Including 2.5 wt % Li3TCA alleviates the decomposition of the electrolyte on the lithium metal interface, decreasing the Li2S content in the solid-electrolyte interface (SEI) thus forming a more stable interface. In Li|Li symmetric cells, this strategy enables a rise in the critical current density from 1.0 to 1.9 mA cm-2 and stable cycling for over 750 hours at a high current density of 1.0 mA cm-2. This approach also enables Li|NbO-NCM811 full cell to operate more than 500 cycles at 0.3 C.

Reconstruction of zinc-metal battery solvation structures operating from −50 ~ +100 °C

Serious solvation effect of zinc ions has been considered as the cause of the severe side reactions (hydrogen evolution, passivation, dendrites, and etc.) of aqueous zinc metal batteries. Even though the regulation of cationic solvation structure has been widely studied, effects of the anionic solvation structures on the zinc metal were rarely examined. Herein, co-reconstruction of anionic and cationic solvation structures was realized through constructing a new multi-component electrolyte (Zn(BF4)2-glycerol-boric acid-chitosan-polyacrylamide, simplified as ZGBCP), which incorporates double crosslinking network via the esterification, protonation and polymerization reactions, thereby combining multiple advantages of ‘liquid-like’ high conductivity, ‘gel-like’ robust interface, and ‘solid-like’ high Zn2+ transfer number. Based on the ZGBCP electrolyte, the Zn anodes achieve record-low polarization and stable cycling. Furthermore, the ZGBCP electrolyte renders the AZMBs ultrawide working temperature (−50 °C ~ +100 °C) and ultralong cycle life (30000 cycles), which further validates the feasibility of the dual solvation structure strategy and provides a innovative perspective for the development of high-performance AZMBs.

A cyclic durable all-solid-state battery constructed with LiBH4-based electrolyte with high ionic conductivity at room temperature

LiBH4 has been considered as a promising solid electrolyte for lithium-ion batteries. However, the low ionic conductivity at room temperature has been the biggest challenge of LiBH4 solid-state electrolyte (SSE) toward practical solid-state batteries. In this work, a ternary electrolyte is designed and prepared by milling LiBH4 with LiNH2 and interfacially decorated with g-C3N4. It is revealed that the soft dispersed phase of two-dimensional g-C3N4 can build an effective transportation network in the composite electrolyte, thereby decreasing the interfacial impedance and reducing the energy barrier for lithium ion diffusion. The optimized SSE, LiBH4-2LiNH2-g-C3N4-10% (LBN-CN-10%), exhibits an ionic conductivity of 1.5×10−3 S cm−1, five orders of magnitude higher than that of the LiBH4 electrolyte at 30oC. The LiIn symmetric cell with LBN-CN-10% electrolyte delivers a low polarization of ~89mV over 10000hours. When assembling with Li4Ti5O12 cathode, the all-solid-state battery exhibits excellent cycling over 1000 cycles at 30 ℃, achieving a breakthrough in the lifetime of solid-state batteries with LiBH4 -based electrolyte. Moreover, the all-solid-state battery with LiNi0.8Co0.1Mn0.1O2 cathode also delivers a discharge plateau at 3.0V, revealing the high voltage withstanding of LBN-CN-10% electrolyte. This work provides new options for the development and practical application of room-temperature hydride all-solid-state batteries.

Multifunctional PDMS/Schiff base/SiO2 gel assisted fabrication of printed, stretchable and straight copper conductors

Printable, stretchable, and highly conductive metal conductors have emerged as potentially promising interconnects in the field of soft electronics. However, current techniques relying on geometric engineering have been criticized for complicated fabrication process and defective geometric structure. Here, we report a printed, straight, and omnidirectionally stretchable copper conductor, which is facilely fabricated on a flat substrate without requiring prestretching, assisted by a multifunctional gel medium layer. The PSS gel, composited by polydimethylsiloxane, Schiff base and fumed SiO2, offers a unique combination of stretchability, printability, and moldability. Additionally, this gel enables the reduction of silver ions directly on its surface by partially bonded crosslinker molecules. The fully exposed catalyst exhibits excellent activity in catalyzing electroless copper deposition reaction, on which high-quality copper coating is facilely achieved. The produced copper patterns exhibit high conductivity (4.93 × 107 S m−1) and excellent stretchability with fracture strains of ∼ 191 % and ∼ 135 % for the uni- and omni-directionally stretchable patterns respectively, which are superior to the majority of stretchable metals in published literature. The stretchable wrinkles derive form the gel medium layer molded by templates, realizing straight metal lines on flat substrate. This process combines the advantages of traditional in-plane and out-of-plane strategies, demonstrating great potential in practical application.

Low Temperature Fast Mixed OH−/H+ Ionic Conductor in Doped Strontium Cerates

AbstractThe drawbacks of high temperature solid oxide fuel cells (HT‐SOFCs) prompt efforts to lower operating temperatures to near ambient temperatures (NAT). Here the high mixed OH−/H+ ionic conductivity in doped SrCeO3 below 100 °C is reported. The SrCe0.8Y0.2O3−δ (SCYO20) electrolyte demonstrates a high ionic conductivity of 12 mS cm−1 in water and 9 mS cm−1 in wet air at 60 °C and an excellent long‐term stability over 100 h. Solid state nuclear magnetic resonance confirms the presence of protons and hydroxide ions in the hydrated oxides and their correlation with Y dopant. Demonstration of direct ammonia fuel cells using the SCYO20 electrolyte indicates the practical application value of this material. The OH− conduction of SrCe0.7Sn0.2Y0.1O3−δ (SCSY721) is demonstrated by electrolysis of D2O. The introduction of KOH significantly increases the availability of OH− feed ions, leading to a remarkable improvement of ionic conductivity of SCSY721 electrolyte which is increased by 27 times, 56.34 mS cm−1 in 6 m KOH at 90 °C. The increased ionic conductivity due to the presence of high concentration of extrinsic conducting ions, here are OH− ions, is called as ‘feeding effect’. This study offers new electrolyte materials for cost‐effective, and durable electrochemical devices such as NAT‐SOFCs.