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Lithium sulfur (Li-S) batteries are highly prospective for future generations of transportation and grid storage due to their high energy density and low cost. However, the Li dendrite growth from the anode and the “polysulfide shuttle” from the cathode may cause poor cycling performance and safety concerns, hindering the practicality of Li-S batteries. Herein, we demonstrate a novel separator design by coating three-dimensional (3D) carbon nanofiber (CNF) interlayers on both sides of the separator to achieve a high performance Li-S battery. The CNF interlayer can not only render a uniform Li deposition on the anode by eliminating the “tip effect”, but also restrain the polysulfide diffusion on the cathode with its porous and highly conductive 3D architecture, enhancing the utilization of S-related species significantly. So an average Coulombic efficiency of the Li metal anode protected by a CNF interlayer is up to 95% for 100 cycles at 0.5 mA cm −2 . Moreover, Li-S batteries with CNF interlayers can exhibit remarkable cycle performance, presenting an initial specific capacity of 1207.4 mAh g −1 at 0.5C and retaining at 828.1 mAh g −1 after 100 cycles. In addition, the low-cost raw materials and the simple preparation for CNF interlayers is suitable for industrial scale-up. [ABSTRACT FROM AUTHOR]

Li-rich materials are considered the most promising for Li-ion battery cathodes, as high capacity can be achieved. However, poor cycling stability is a critical drawback that leads to poor capacity retention. Here a strategy is used to synthesize a large-grain lithium-rich layered oxides to overcome this difficulty without sacrificing rate capability. This material is designed with micron scale grain with a width of about 300 nm and length of 1–3 μm. This unique structure has a better ability to overcome stress-induced structural collapse caused by Li-ion insertion/extraction and reduce the dissolution of Mn ions, which enable a reversible and stable capacity. As a result, this cathode material delivered a highest discharge capacity of around 308 mAh g −1 at a current density of 30 mA g −1 with retention of 88.3% (according to the highest discharge capacity) after 100 cycles, 190 mAh g −1 at a current density of 300 mA g −1 and almost no capacity fading after 100 cycles. Therefore, Lithium-rich material of large-grain structure is a promising cathode candidate in Lithium-ion batteries with high capacity and high cycle stability for application. This strategy of large grain may furthermore open the door to synthesize the other complex architectures for various applications. [ABSTRACT FROM AUTHOR]

Compositionally continuously graded cathode layers (CGCLs) of (Ba0.5Sr0.5)(Fe0.91Al0.09)O3−δ –Gd0.1Ce0.9O2 (BSFA–GDC) have been constructed by a handy and effective technique called wet powder spraying (WPS). CGCLs exhibit similar thermal expansion coefficient (TEC) value between adjacent thin layers. The continuously graded structure and the well-distributed components of BSFA–GDC cathode are confirmed by morphological characterization with scanning electron microscopy (SEM), and by compositional analysis with energy dispersion X-ray spectrometer (EDS), respectively. The polarization resistance (R p) of CGCLs with three different thicknesses is investigated by electrochemical impedance spectra (EIS). The EIS results show that CGCLs with a moderate thickness of 20 μm achieve the lowest R p of 0.301 Ω cm2 at 800 °C. In addition, anode-supported single cells with the configuration of NiO–YSZ/YSZ/GDC/BSFA–GDC have been fabricated and tested. The cell with the CGCLs thickness of 20 μm reaches the highest output power density of 848 mW cm−2 at 800 °C. [ABSTRACT FROM AUTHOR]

Abstract: Herein a chemical reduction method is proposed in order to modify the solid oxide fuel cells (SOFC) traditional cathode material La0.8Sr0.2MnO3−x (LSM). Silver nanoparticles were prepared by the reduction of ammoniacal silver nitrate with ascorbic acid in dilute aqueous solutions containing PVP. The obtained LSM–Ag composite powders were characterized by XRD, SEM, EDX, and STEM. The results showed that the LSM–Ag composite powder possess an elaborated fine structure with a homogeneous distribution of Ag and LSM, which effectively shortens the diffusion pathway for electrons and adsorbed oxygen. The electrochemical performance of the LSM–Ag cathode with different Ag loadings was investigated. A cathode loading with 1 wt.% Ag exhibited an area specific resistance as low as 0.45 Ω cm2 at 750 °C, compared to around 1.1 Ω cm2 for a pure LSM electrode. Similarly an anode-supported SOFC with 1 wt.% Ag in the cathode shows a peak power density of 1199 mW cm−1, higher than the value of 717 mW cm−1 achieved for a similar cell with a LSM cathode. Increasing the Ag loading is shown to have an insignificant effect on improving electrocatalytic performance at 750 °C, however it can increase output power at 650 °C. [Copyright &y& Elsevier]

Abstract: A Sr2Fe1.5Mo0.5O6–Sm0.2Ce0.8O1.9 (SFMO–SDC) nanocomposite material has been prepared by the self-combustion method. The phase structure and morphology of the material have been characterized by means of X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). These results show the coexistence of perovskite and fluorite structures within the porous microstructure which are uniformly distributed throughout the prepared samples. The electrochemical performance of the material has been investigated by electrochemical impedance spectroscopy (EIS) measurements. Using an SDC interlayer SFMO–SDC composite cathode is prepared and applied onto a standard YSZ (8% Y2O3-stabilized ZrO2) electrolyte. A low polarization resistance of the prepared sample is obtained and remarkable performance of the SFMO–SDC based IT-SOFCs is achieved. It is demonstrated that the SFMO–SDC/SDC/YSZ/NiO–YSZ fuel cell reached power densities of 2.21, 1.66, 1.16 and 0.71 W cm−2 at 800, 750, 700 and 650 °C, respectively, in humidified H2 (3 vol% H2O). [Copyright &y& Elsevier]

LiCoO2 (LCO) has been widely adopted as the electrode for lithium‐ion batteries (LIBs) which provide a solution for settling problems referring to energy and environment. The demand for rapid and controllable synthesis of LCO increases dramatically. In this work, reactive flash sintering (RFS), for the first time, was introduced to synthesize LCO rapidly and controllably based on simple oxide precursors. The as‐prepared LCO, investigated by physicochemical property characterization, showed well‐constructed and high crystallinity and controllable morphologies, in which the grain size varied with the magnitude of the applied limited current value, allowing for grain size modulation. Furthermore, the as‐prepared LCO exhibited excellent performance in cyclic stability and rate capacity by contrast with that synthesized by the conventional solid‐phase sintering method. This is admittedly attributed to better crystallinity and less lithium loss. Therefore, RFS provides a new approach for the manufacture of LCO electrode and has the potential to be applied to other electrode materials for LIBs. [ABSTRACT FROM AUTHOR]

Solid oxide electrolysis cell (SOEC) is recognized as an effective means to accomplish sustainable development since it is an efficient electrochemical technology for CO 2 emission reduction. However, the electrocatalytic reduction activity of the cathode for CO 2 restricts the development of SOEC. Herein, an A-site deficient perovskite Sr 1·9 Fe 1·3 Cu 0·2 Mo 0·4 Ti 0·1 O 6-δ (SFCMT) was proposed as cathode material that can in situ exsolve uniform Cu nanoparticles. The exsolution of Cu increases the concentration of oxygen vacancies and provides abundant adsorption sites for CO 2 , resulting in excellent electrochemical catalytic capacity. Cu@SFCMT-based single cells exhibit excellent electrolytic performance under pure CO 2 , with current densities up to 3.21 A cm−2 at 1.8 V and 800 °C and interface polarization resistance (Rp) as low as 0.20 Ω cm2 at 800 °C. Furthermore, the current density changes slightly after the 140 h stability test at 1.2 V. Cu@SFCMT exhibits outstanding electrochemical activity and durability, making it a viable SOEC cathode material. [ABSTRACT FROM AUTHOR]

Protonic ceramic fuel cells (PCFCs) have generated significant interest due to their weak temperature dependence and efficient energy conversion. However, traditional cathode materials show poor electrocatalytic activity at a low operating temperature due to their intrinsically slow proton diffusion, which is a long-standing issue that limits the output performance of PCFCs. Herein, the strategy of fluorinating a perovskite cathode is proposed for promoting proton transfer within the bulk of the cathode. This strategy is demonstrated in a fluorinated BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3−δ (BCFZY) perovskite, which reveals a reduced polarization resistance and enhanced PCFC output performance, superior to those of newly reported PCFCs. Combing the experimental characterization and theoretical calculations, we found that the performance improvement was ascribed to the strong inductive effect of F−, which can increase the polarity the M−O bonding and decrease the O···H interaction, thus boosting the production of protonic defects and increasing the protonic diffusion coefficient. [Display omitted] • Fluorinated BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3−δ (BCFZY) perovskite is firstly synthesized as PCFC cathode. • Fluorination enhances the hydration properties and proton mobility of BCFZY perovskite. • Fluorination inductive effect has been proposed to reveal the origin of improved proton mobility. • Peak power density of 0.782 W cm−2 is obtained at 600 °C for a single PCFC using fluorinated BCFZY as cathode. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries have aroused great interest in the context of rechargeable batteries, while the shuttle effect and sluggish conversion kinetics severely handicap their development. Defect engineering, which can adjust the electronic structures of electrocatalyst, and thus affect the surface adsorption and catalytic process, has been recognized as a good strategy to solve the above problems. However, research on phosphorus vacancies has been rarely reported, and how phosphorus vacancies affect battery performance remains unclear. Herein, CoP with phosphorus vacancies (CoP‐Vp) is fabricated to study the enhancement mechanism of phosphorus vacancies in Li–S chemistry. The derived CoP‐Vp features a low Co‐P coordination number and the introduced phosphorus vacancies mainly exist in the form of clusters. The obtained CoP‐Vp can reinforce the affinity to lithium polysulfides (LiPSs) and thus the shuttle effect can be restrained. In addition, the reduced reaction energy barriers and the promoted diffusion of Li+ can accelerate redox kinetics. Electrochemical tests and in situ Raman results confirm the advantages of phosphorus vacancies. The S/CNT‐CoP‐Vp electrode presents outstanding cycling performance and achieves a high capacity of 8.03 mAh cm−2 under lean electrolyte condition (E/S = 5 μLE mg−1S). This work provides a new insight into improving the performance of Li–S batteries through defect engineering. [ABSTRACT FROM AUTHOR]

Abstract: Nanoporous composite oxides Sr2Fe1.5Mo0.5O6–Sm0.2Ce0.8O1.9 (SFM–SDC) have been prepared by a facile one-step method as cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The SFM–SDC composite materials have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and electrochemical impedance spectroscopy (EIS). The EIS results exhibit that SFM–SDC40 (wt% 60:40) cathode has encouraging electrochemical performance with low polarization resistance (R p) on YSZ (Y2O3-stabilized ZrO2) electrolyte. Subsequently, bi-layer cathodes SDC/SFM–SDC are fabricated, and excellent electrochemical performance of such composite cathodes are observed. We demonstrate that the SDC interlayer significantly decreases the R p of cathode and accelerates the charge transfer process. As a result, the R p of the SDC/SFM–SDC40 bi-layer cathodes is almost 50% less than that of SFM–SDC40 cathode on YSZ electrolyte at 800 °C, and R p is only 0.11 Ω cm2. Compared with single cells without an interlayer, the anode-supported single cells with SDC interlayer exhibit enhancement in overall power performance. [Copyright &y& Elsevier]

LaNiO oxide was synthesized as a cathode material for intermediate-temperature solid oxide fuel cells by a facile sol-gel method using a nonionic surfactant (EO)106(PO)70(EO)106 tri-block copolymer (F127) as the chelating agent. The crystal structure, electrical conductivity, and electrochemical properties of LaNiO were investigated by X-ray diffraction, DC four-probe method, electrochemical impedance spectra, and I-V measurements. The LaNiO cathode showed a significantly low polarization resistance (0.26 Ω cm) and cathodic overpotential value (0.037 V at the current density of 0.1 A cm) at 750 °C. The results measured suggest that the diffusion process was the rate-limiting step for the oxygen reduction reaction. The LaNiO cathode revealed a high exchange current density value of 62.4 mA cm at 750 °C. Furthermore, an anode-supported single cell with LaNiO cathode was fabricated and tested from 650 to 800 °C with humidified hydrogen (∼3 vol% HO) as the fuel and the static air as the oxidant. The maximum power density of 900 mW cm was achieved at 750 °C. [ABSTRACT FROM AUTHOR]

Proton conducting solid oxide fuel cells (H–SOFCs) with BaZr 0·1 Ce 0·7 Y 0·2 O 3-δ as electrolyte were fabricated to couple the removal of nitrogen oxides in power generation technology. Specially, a deliberately designed cathode with the composition of La 0·3 Sr 0·7 Mn 0·8 Mg 0·2 O 3−δ was prepared to realize this dual function. The results indicated that the incorporation of Mg ions in La 0·3 Sr 0·7 MnO 3−δ can improve its ability to adsorb NO and the cathode activity. At 800 °C, when using the NO as oxidant, single cell with La 0·3 Sr 0·7 Mn 0·8 Mg 0·2 O 3−δ cathode was able to obtain peak power density of 48 mW cm−2 and achieve the conversion of NO to N 2 more than 48%. These findings suggested that power generation coupling deNO via H–SOFC is possible and La 0·3 Sr 0·7 Mn 0·8 Mg 0·2 O 3−δ was a promising cathode for this application. [ABSTRACT FROM AUTHOR]

Solid oxide electrolysis cell (SOEC) has great application prospects in the fields of renewable energy storage, CO 2 capture and utilization. One of the key factors hindering the development of SOEC is the lack of suitable cathode materials. In this study, we designed and developed a kind of new micro-nano heterostructure materials Co@Sr 1.95 Fe 1.4 Co 0.1 Mo 0.4 Ti 0.1 O 6-δ (Co@SFCMT), Co nanoparticles uniformly distributed on the SFCMT matrix and provided rich electric catalytic active sites, SFCMT showed excellent oxygen ion transport performance. The synergistic effect of Co nanoparticles and Sr 1.95 Fe 1.4 Co 0.1 Mo 0.4 Ti 0.1 O 6-δ (SFCMT) increased the rate of CO 2 reduction reaction (CO 2 RR). At 1.8 V and 800 °C, the maximum electrolytic current density of the cell with Co@SFCMT as the cathode reached 2.57 A cm−2. In addition, Co@SFCMT showed good stability at 1.5 V and 750 °C, with no performance decay even after 200 h of continuous operation. The micro-nano heterostructure design strategy of perovskite oxides will not only open new avenues for designing SOEC electrodes, but also be expected to promote the development of other energy storage and conversion systems. • A novel heterostructure cathode material for solid oxide electrolysis cell was prepared. • The Co@Sr 1.95 Fe 1.4 Co 0.1 Mo 0.4 Ti 0.1 O 6-δ material exhibited high activity and stability. • Structural stability of the material was regulated by introducing Ti. • No performance decay was observed after 200 h of operation. [ABSTRACT FROM AUTHOR]

Perovskite oxide Sr2Fe1.3Cu0.2Mo0.5O6−δ (SFCM) is prepared and evaluated as a novel cathode material for solid oxide electrolytic cells (SOECs). At 750 °C, the interfacial polarization resistance value decreased from 1.834 to 1.125 Ω cm2 and the SFCM cathode exhibited excellent stability for 100 h, without any significant attenuation, at an electrolytic voltage of 1.5 V. [ABSTRACT FROM AUTHOR]

Abstract FeF 2 -reduced graphene oxide nanocomposite is in-situ synthesized and assembled into electrode with poly (acrylic acid) binder as a novel sodium ion cathode, which exhibits greatly improved electrochemical performance. The mechanism for the improved performance of the electrode is studied by ex-situ morphology and phase analysis, before and after cycling. The results show that poly (acrylic acid) binder with high adhesion ability can stabilize the electrode structure, thus increase the utilization of active materials. The in-situ hybridization of FeF 2 nanoparticles with reduced graphene oxide can confine the sizes of particles, and restrain the particles agglomeration. As a result, the electrode can attain high capacity and stability. The electrode exhibits superior electrochemical performance: high capacity of 175 mAh g−1 at 0.2 A g−1, high rate capability of 78 mAh g−1 at 10 A g−1, and good cycling stability. The results demonstrate the electrochemical performance of metal fluoride electrode can be enhanced by using highly adhesive materials as binders and the nanostructure construction. Graphical abstract Image 1 Highlights • A novel electrode is prepared using FeF 2 -rGO nanocomposite and PAA binder. • The electrode shows improved capacity, rate capability and cyclic performance. • The improved performance is studied by ex-situ morphology and phase analysis. • PAA binder can increase the utilization of active materials. [ABSTRACT FROM AUTHOR]

The common high-capacity cathode Li2C6O6 shows poor cycling performance because of its dissolution in electrolytes. Using morphology control, spherical Li2C6O6 was prepared, and then combined with reduced graphene oxide and modified with an FeF3 coating. This interface engineering inhibited the dissolution of Li2C6O6, and also enhanced its cycling and rate performance. [ABSTRACT FROM AUTHOR]

In this paper, the partial substitution of atomic elements from the A site of a perovskite is investigated in order to develop cathode materials for solid oxide fuel cell (SOFC) applications. Herein, Sr 2−x Ca x Fe 1.5 Mo 0.5 O 6−δ (SCFM), compounds were investigated by characterizing structural properties, chemical compatibility, electrical properties, electrochemical performance and stability. Thermal expansion coefficients were found to decrease when increasing the Ca content. X-ray photoelectron spectroscopy analysis suggests that Ca doping significantly affects the Fe 2+ /Fe 3+ and Mo 6+ /Mo 5+ ratios. For a doping level of x = 0.4, the sample showed the lowest interface polarization ( R p ), the highest conductivity and a maximum power density of 1.26 W cm −2 at 800 °C. These results suggest that SCFM cathode materials are excellent candidates for intermediate temperature solid oxide fuel cells applications. [ABSTRACT FROM AUTHOR]

A strategy of regulating the basicity of perovskite oxygen ions by cation doping is proposed to design cathode materials with high catalytic activity for solid oxide electrolysis cells (SOECs). Specifically, a series of Sr 2 Fe 1.5- x Zr x Mo 0.5 O 6−δ (SFZ x M) perovskites are developed and characterized for its electrocatalytic activity and oxygen ions basicity to investigate the effect on electrochemical performance. The experimental results show that the single cell prepared with the Sr 2 Fe 1.3 Zr 0.2 Mo 0.5 O 6−δ (SFZ2M) cathode reaches a current density of 1.85 A cm−2 at 1.8 V and 800 °C and exhibits good stability over 120 h under CO 2 atmosphere. Combined with first-principles calculations, it is further confirmed that the introduction of low-electronegativity ions can improve the oxygen ions basicity and also increase the oxygen vacancy concentration of the cathode, thereby realizing the improvement of electrochemical performance. Thus, this strategy provides new insights into designing electrodes for direct CO 2 electrolysis as well as other electrochemical catalysis. [Display omitted] • Zr-doped Sr 2 Fe 1.5 Mo 0.5 O 6-δ (SFZxM) perovskites are firstly evaluated as SOEC cathode. • SFZxM materials greatly enhance the chemisorption of CO 2 by increasing the oxygen vacancies concentration. • The introduction of Zr4+ can improve the oxygen ion basicity of SFZxM cathodes. • The improved electrochemical performance is facilitated by the double regulation of oxygen ion basicity and oxygen vacancies. [ABSTRACT FROM AUTHOR]

[Display omitted] • (PrBa) 0.95 Fe 1.6 Ni 0.2 Nb 0.2 O 5+δ as the cathode material of SOEC is reported first time. • In situ fabrication of highly active nanoalloy catalyst for CO 2 RR. • The abundant oxygen vacancies and active nanoalloy significantly improves the mass transfer process. • Good electrochemical performance and stability induced by efficient cathode reactions. The electroreduction of CO 2 through solid oxide electrolysis cells (SOEC) is considered as a promising technology for mitigating climate changes related to global warming. A SOEC system can effectively reduce polarization losses and best utilize process heat to electrolyze CO 2 to produce CO. However, this technology is hindered by the sluggish cathode kinetics, which is mainly due to the poor catalytic activity for the CO 2 reduction reaction. Herein, this work develops an A-site ordered layered perovskite oxide, (PrBa) 0.95 Fe 1.6 Ni 0.2 Nb 0.2 O 5+δ (PBFNN), as an efficient cathode catalyst for CO 2 -SOEC. FeNi 3 nanoparticles are in situ generated on the surface of perovskite substrate after reduction, the resulting active alloy-perovskite interfaces between FeNi 3 and PBFNN substrate can effectively promote the CO 2 reduction reaction (CO 2 RR). The nanoparticles and abundant oxygen vacancies of FeNi 3 -PBFNN significantly enhance CO 2 adsorption and activation, which is verified by the CO 2 -temperature programmed desorption measurement and density functional theory calculations. Distribution of relaxation time analysis and electrochemical performance characterization indicate that this interface engineering at nanoscale greatly improves the catalytic activity of the cathode for CO 2 RR. [ABSTRACT FROM AUTHOR]

Herein, we report a facile and effective adsorption strategy to improve the performance of Lithium-Sulfur (Li-S) batteries. MnO 2 nanosheets grown on the surface of highly conductive graphene resulted in a coupled composite bilayer electrode when coated onto a sulfur cathode. In this way, a high initial specific capacity of 1395 mA h g −1 at a rate of 0.5C, a coulombic efficiency approaching 100% and steady cyclic efficiency with a fade rate of 0.3% per cycle from 10 to 100 cycles has been achieved. This hybrid electrode not only shows enhanced electrochemical performance but can also be easily controlled and scaled thereby aiding future commercialization of high-performance Li-S batteries. [ABSTRACT FROM AUTHOR]

Abstract: La3Ni2O7 oxide has been synthesized by a facile sol–gel method using a nonionic surfactant (EO)106(PO)70(EO)106 tri-block copolymer (Pluronic F127) as the chelating agent. The pure phase of La3Ni2O7 has been obtained by sintering at temperatures of 1100°C for 12h. La3Ni2O7 oxide as a cathode presents no visible reaction with an Y2O3-stabilized ZrO2 (YSZ) electrolyte. The electrochemical performance of the prepared oxide as a cathode has been investigated. Area specific resistance of La3Ni2O7 material on YSZ electrolyte is as low as 0.39Ωcm2 at 750°C. Furthermore, an anode-supported single-cell configuration of NiO–YSZ/YSZ/La3Ni2O7 has been achieved a maximum power density of 848mWcm−2 at 750°C. The cell performance was stable under a constant current of 0.6Acm−2 for over 30h at 750°C. These results therefore suggest that La3Ni2O7 synthesized by this sol–gel method is a highly promising cathode material for applications in IT-SOFCs. [Copyright &y& Elsevier]

A free-standing and flexible sulfur host material composed of Mo 2 C nanoarrays growing on the surface of carbon cloth (Mo 2 C/CC) is designed for the binder-free cathode of the Lithium-sulfur (Li–S) batteries. The carbon cloth substrate is flexible together with the conductive bottlebrush-like Mo 2 C, this host material can provide more active sites and a large inner space to accommodate the volume expansion of sulfur to Li 2 S 2 /Li 2 S. The electric conductive Mo 2 C nanoarrays can not only adsorb the polysulfides through forming Mo–S bonds to inhibit the shuttle of lithium polysulfides (LiPSs), but also can boost the electron transfer and promote the direct conversion of the LiPSs to Li 2 S 2 /Li 2 S on their surface. As a result, the sulfur cathodes based on the Mo 2 C/CC host material exhibit an impressive specific capacity of 1213 mA h g-1 at 0.1 C, maintain a long-term cyclability with a decay of 0.011% per cycle. More remarkably, excellent capacity of 8.57 mA h cm-2 can be attained with a high sulfur loading (10.8 mg cm−2) benefit from the 3D nanoarrays structure of the Mo 2 C/CC host material. Meanwhile, a pouch cell based on Mo 2 C/CC@S cathode can cycle steadily. Mo 2 C/CC absorbs and enhances the reaction kinetic of the random polysulfides on their surface directly, so inhibits the shuttle effect of the Li–S battery. [Display omitted] • A free-standing and flexible sulfur host material Mo 2 C/CC has been prepared. • Mo 2 C/CC with 3D structure can alleviate the volume expansion of S. • Excellent performance comes from the adsorption and catalytic behavior of Mo 2 C. [ABSTRACT FROM AUTHOR]

• Cu-doped (La 0.2 Sr 0.8) 0.95 Ti 0.65- x Mn 0.35 Cu x O 3- δ(LSTMC)are firstly evaluated as SOEC cathode. • LSTMC greatly enhances the catalytic activity by enhancing the chemisorption of CO 2. • The catalytic reaction mechanisms of LSTMC are discussed. • A max electrolytic current density of 2.33 A cm−2 is obtained under 1.8 V at 800 °C. Solid oxide electrolysis cell (SOEC) is a promising technology to efficiently convert carbon dioxide. However, the lack of suitable cathode, with desirable catalytic activity, limits the advancement of SOEC. Herein, we report a novel (La 0.2 Sr 0.8) 0.95 Ti 0.65- x Mn 0.35 Cu x O 3-δ (LSTMC x , x = 0, 0.05, 0.1 and 0.15) as a high-performance cathode, co-doped with hetero-valent Cu and Mn ions at B-site synergistically regulates the surface environment of LST. Cu doping significantly improved the catalytic activity by enhancing the chemisorption of CO 2 , and Mn doping increased the concentration of oxygen vacancies, resulting in abundant electrochemically active sites. Moreover, the as-prepared LSTMC render a higher electrocatalysis performance (2.33 A cm−2 at 1.8 V and 800 °C) than the previously reported perovskite-based cathodes. In addition, the LSTMC-based single cell did not exhibit any significant performance degradation after long-term stability test (100 h) under pure CO 2. Therefore, this newly developed perovskite is considered as a promising cathode for SOEC. [ABSTRACT FROM AUTHOR]

The development of cathode materials, with high catalytic activity toward oxygen reduction reaction (ORR), structural stability and CO 2 tolerance, is an important research direction for the successful realization of intermediate-temperature solid oxide fuel cells (IT-SOFCs). Herein, a novel double perovskite mixed ionic conductor, i.e., Sr 2 Fe 1.3 Ga 0.2 Mo 0.5 O 6-δ (SFGM), is developed by Ga-doping at Fe-sites of Sr 2 Fe 1.5 Mo 0.5 O 6-δ (SFM) and evaluated as a cathode material in IT-SOFCs. At 750 °C, the area specific resistance (ASR) of SFGM cathode is found to be 0.099 Ω cm2, which is ~50% lower than SFM cathode (0.224 Ω cm2) in 20% O 2 /N 2 atmosphere. Moreover, SFGM exhibits outstanding CO 2 tolerance due to its excellent CO 2 adsorption resistance compared with SFM. The ASR of SFGM remains stable at ~0.13 Ω cm2 during 100 h of continuous operation in 5% CO 2 -containing air. In addition, a large-sized SFGM cathode (30 cm2) is utilized in anode-supported flat-tube SOFCs to demonstrate the potential of SFGM in practical applications. At 750 °C, the as-prepared SFGM-based single-cell provides a stable power of 12 W for 291 h in 5% CO 2 -containing air. The superior electrochemical performance and outstanding CO 2 tolerance of SFGM are promising features for the rapid development of IT-SOFCs. Image 1 • SFGM are firstly evaluated as the cathode for flat tubular solid oxide fuel cell. • Ga-doping enhanced the oxygen-ion transport capability of SFM-based materials. • A low polarization resistance of 0.099 Ω cm2 at 750 °C for SFGM cathode. • SFGM exhibits outstanding CO 2 tolerance. [ABSTRACT FROM AUTHOR]