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A sustainable process is designed to produce anode‐supported solid oxide fuel cells (SOFCs). Environmentally friendly solvents and additives are selected to prepare sequentially cast slurries to obtain a flexible multilayer tape whose cohesion is ensured by a 3D network of binder. This tape includes the components of the oxide precursor of the half cell with the functional and structural part of the anode. The optimization of debinding and sintering processes allows converting green tape into sintered multilayer ceramic using a single heat treatment. The use of optimized loads maintains planarity of samples with adjusted shape (circular to square) and size (from 0.8 up to 8 cm2) of anodic half cell. The cell's oxide precursor is supplemented by screen printing the cathode and converted to anode‐support SOFC when the cell is first used. The whole process maintains mechanical integrity, microstructure of structured components, and insures interfaces enabling charge transfer high enough to achieve standard performances such as power of 411 mW cm−2. The selection of cheap and harmless solvents and additives and the optimization of heat treatment lead to an ecocompatible low‐cost process for manufacturing SOFCs, easily transferable to the industrial scale and suitable for the manufacture of all systems based on ceramic multilayers. [ABSTRACT FROM AUTHOR]

Mechanical degradation in electrode materials during successive electrochemical cycling is critical for battery lifetime and aging properties. A common strategy to mitigate electrode mechanical degradation is to suppress the volume variation induced by Li/Na intercalation/deintercalation, thereby designing strain-less electrodes. In this study, we investigate the electrochemically-induced volume variation in layered and spinel compounds used in Li-ion and Na-ion battery electrode materials through density functional theory computations. Specifically, we propose to decompose the volume variation into electronic, ionic, and structural contributions. Based on this analysis, we suggest methods to separately influence each contribution through strategies such as chemical substitution, doping, and polymorphism. Altogether, we conclude that volume variations can be controlled by designing either mechanically hard or compact electrode materials. [ABSTRACT FROM AUTHOR]

A low‐cost manufacturing procedure has been developed for the fabrication of planar anode‐supported solid oxide fuel cell including only two thermal treatments. This method is also environmental friendly because slurries are water based and use nontoxic additives. Slurries are formulated by optimizing the powder quantity, by minimizing the organic compounds while controlling their stabilities and their rheological properties. Flexible multilayer green tapes have been produced by using the reverse sequential tape‐casting method. After a cosintering thermal treatment under loads, planar anodic half‐cells have been produced allowing the deposition of a La2NiO4+δ cathode by screen printing. After the final consolidation thermal treatment, the cell presents a 30 μm‐thick porous cathode, a 530 μm‐thick NiO‐YSZ porous anode, and a 80 μm‐thick dense electrolyte with a gradient of composition: 10GDC on the cathode side to prevent the apparition of the La2Zr2O7 insulating phase and 8YSZ on the anode side to avoid the reduction of 10GDC with the fuel gas. Power densities present promising performances (319 mW cm−2 at 830 °C) given that electrolyte thickness and electrochemical system measurement may be improved. [ABSTRACT FROM AUTHOR]

All solid‐state batteries (ASSB) are the next generation of safe and high‐energy‐density energy storage technology. Their development is currently impeded by the stability issues of solid‐state electrolyte (SSE) limiting the creation of interfaces of quality high enough to ensure efficient transfer of charges. The garnet Li7−xLa3Zr2−xTaxO12 (LLZO:Ta) is one of the most appealing oxide‐based SSE but its high sensitivity to moist air engenders difficulties in designing process to densify and assemble components of the ASSB. Based on a careful investigation of LLZO:Ta thermal and chemical stability, a heat treatment is designed and shown to fully reverse the protonation process. The investigation of spark plasma sintering protocols confirms that pretreated LLZO:Ta can be densified at a temperature as low as 850 °C or with a short duration (few seconds) at 900 °C. The characterization of obtained ceramics shows conductivities close to the bulk properties and confirms the absence of influence of grain boundaries. The study of composite electrodes shows that LLZO:Ta is suitable to act both as SSE separator and ionic percolator in positive electrode, the selection of active material remains the main issue to target self‐standing Li‐based ASSB. [ABSTRACT FROM AUTHOR]

MXenes, a rapidly growing family of 2D transition metal carbides, carbonitrides, and nitrides, are one of the most promising high‐rate electrode materials for energy storage. Despite the significant progress achieved, the MXene synthesis process is still burdensome, involving several procedures including preparation of MAX, etching of MAX to MXene, and delamination. Here, a one‐pot molten salt electrochemical etching (E) method is proposed to achieve Ti2C MXene directly from elemental substances (Ti, Al, and C), which greatly simplifies the preparation process. In this work, different carbon sources, such as carbon nanotubes (CNT) and reduced graphene oxide (rGO), are reacted with Ti and Al micro‐powders to prepare Ti2AlC MAX with 1D and 2D tuned morphology followed by in situ electrochemical etching from Ti2AlC MAX to Ti2CTx MXene in low‐cost LiCl‐KCl. The introduction of the O surface group via further ammonium persulfate (APS) treatment can act in concert with Cl termination to activate the pseudocapacitive redox reaction of Ti2CClyOz in the non‐aqueous electrolyte, resulting in a Li+ storage capacity of up to 857 C g−1 (240 mAh g−1) with a high rate (86 mAh g−1 at 120 C) capability, which makes it promising for use as an anode material for fast‐charging batteries or hybrid devices in a non‐aqueous energy storage application. [ABSTRACT FROM AUTHOR]

Recently, rechargeable zinc‐ion batteries in mild acidic electrolytes have attracted considerable research interest as a result of their high sustainability, safety, and low cost. However, the use of conventional Zn‐ion storage materials is hindered by insufficient specific capacity, sluggish reaction kinetics, or poor cycle life. Here, these limitations are addressed by pre‐intercalating alkali ions and water crystals into layered δ‐MnO2 (birnessite) to prepare K0.27MnO2·0.54H2O (KMO) and Na0.55Mn2O4·1.5H2O with ultrathin nanosheet morphology via a rapid molten salt method. In these materials, alkali ions and water crystals act as pillars to stabilize the layered structures, which can enable rapid diffusion of cations in the KMO structure, resulting in high power capability (90 mAh g−1 at 10 C) and good cycling stability. Furthermore, electrochemical quartz crystal microbalance measurements shed light on the charge storage mechanism of KMO in an aqueous Zn‐ion battery which, combined together with in‐operando X‐ray diffraction techniques, suggests that the charge storage process is dominated by the (de)intercalation of H3O+ with further dissolution–precipitation of Zn4(OH)6(SO4)·5H2O solid product on the KMO surface during cycling. [ABSTRACT FROM AUTHOR]

In the pursuit of facile, fast, and efficient methods for the synthesis of various compounds for a variety of applications, spark plasma sintering (SPS) technique is considered to be a powerful and simple tool. Using this technique, a popular cathode material for Na‐ion batteries—Na3V2(PO4)2F3—is synthesized and characterized with X‐ray diffraction and scanning electron microscopy (SEM), and is electrochemically tested in Swagelok‐type cells in a galvanostatic mode. The obtained material is compared with the conventionally synthesized (via a solid‐state route) sample. SEM analysis shows 2 times smaller particles in the case of SPS‐synthesized material compared with the solid‐state‐synthesized material which is to be expected from the fast (40 min in total) SPS synthesis that practically excludes grain/particle growth and promotes much faster diffusion, thereby drastically enhancing the reaction kinetics. Electrochemical performance of the SPS‐obtained material shows an improvement in decreasing the overpotential and reducing the capacity loss at high C‐rates (8C). [ABSTRACT FROM AUTHOR]

Employing high-rate ion-intercalation electrodes represents a feasible way to mitigate the inherent trade-off between energy density and power density for electrochemical energy storage devices, but efficient approaches to boost the charge-storage kinetics of electrodes are still needed. Here, we demonstrate a water-incorporation strategy to expand the interlayer gap of α-MoO3, in which water molecules take the place of lattice oxygen of α-MoO3. Accordingly, the modified α-MoO3 electrode exhibits theoretical-value-close specific capacity (963 C g−1 at 0.1 mV s−1), greatly improved rate capability (from 4.4% to 40.2% at 100 mV s−1) and boosted cycling stability (from 21 to 71% over 600 cycles). A fast-kinetics dual-ion-intercalation energy storage device is further assembled by combining the modified α-MoO3 anode with an anion-intercalation graphite cathode, operating well over a wide discharge rate range. Our study sheds light on a promising design strategy of layered materials for high-kinetics charge storage. The power/energy trade-off is a common feature seen in a Ragone plot for an electrochemical storage device. Here the authors approach this issue by showing water-incorporated α-MoO3 anodes with expanded interlayer gaps, which allow for the assembling of dual-ion energy storage devices. [ABSTRACT FROM AUTHOR]

A dense membrane of lithium aluminum titanium phosphate Li1+ xAl xTi2− x( PO4)3, x = 0.3 ( LATP) is deposited on a porous LATP substrate via wet chemistry. In the polymerized complex process, phosphate precursors with different active groups and steric hindrance are selected to tune precursor's reactivity. Rheological studies and microstructural observations lead to the selection of an LATP powder slurry charged with lithium, aluminum, titanium, and phosphate ion precursors. The optimized formulation is impregnated into a porous LATP substrate. After thermal treatment, dense LATP membranes on top of a porous LATP substrate are obtained with conductivities as high as 3 × 10−4 S/cm for the dense part, the porous part acting as a mechanical support. An original Van der Pauw impedance setup is validated for the measurement of the ionic conductivity of such dense/porous systems. [ABSTRACT FROM AUTHOR]

Infrared transparent glass–ceramics have been prepared in the system GeS2–Sb2S3–CsCl using spark plasma sintering in shorter times in comparison with conventional thermal treatments. The combined effects of pressure, time, and temperature allow the controlled crystallization of Cs-based crystals. The different glass–ceramics have been characterized by scanning electron microscopy and X-ray diffraction. The optical properties were also investigated. [ABSTRACT FROM AUTHOR]

Studies the crystal structure of aquahydroxidocopper(II) oxovanadium(IV) vanadate Cu(H[sub2]O)(OH)VO(VO[sub4]). Arrangement of vanadate tetrahedra and distorted oxavanadium octahedra in the crystal structure; Values of bond-valence sums of atoms copper and vanadium present in the compound; Analysis of bond angles and bond distances in the compound.

Determines the structure of a single crystal of KVTeO[sub 5] potassium vanadium tellurite. Refinement of the NaVTeO[sub 5] homologue; Formation of a distorted triangular bipyramid with four O atoms; Description of the crystal structure.

The revival of the Na‐ion battery concept has prompted intense research activities toward new sustainable Na‐based insertion compounds and their implementation in full Na‐ion cells. Efforts are parted between Na‐based polyanionic and layered compounds. For the latter, there has been a specific focus on Na‐deficient layered phases that show cationic and anionic redox activity similar to a Na0.67Mn0.72Mg0.28O2 phase. Herein, a new alkali‐deficient P2‐Na2/3Mn7/9Zn2/9O2 phase using a more electronegative element (Zn) than Mg is reported. Like its Mg counterpart, this phase shows anionic redox activity and no O2 release despite evidence of cationic migration. Density functional theory (DFT) calculations show that it is the presence of an oxygen nonbonding state that triggers the anionic redox activity in this material. The phase delivers a reversible capacity of 200 mAh g−1 in Na‐half cells with such a value be reduced to 140 mAh g−1 in full Na‐ion cells which additionally shows capacity decay upon cycling. These findings establish Na‐deficient layered oxides as a promising platform to further explore the underlying science behind O2 release in insertion compounds based on anionic redox activity. The doping of layered sodium based oxide with Zn electronegative d10 ions allows adaptation of energy bands to create nonbonding O(2p) states that can be activated. Characterization carried out ex situ and in operando shows that P2‐Na2/3[Mn7/9Zn2/9]O2 demonstrates reversible cumulative cationic and anionic redox activity while, despite no O2 release, a migration of cations occurs progressively. [ABSTRACT FROM AUTHOR]

A single crystal of MoVAlO7, vanadium aluminium molybdate, has been grown. The present structure determination is more precise than a previous powder-pattern investigation [Knorr, Jacubus, Dabrowska & Kurzawa (1998). Eur. J. Solid State Inorg. Chem. 35, 519-530]. A three-dimensional [MoAlO6]3 n− n network surrounds infinite strings of [VO]3+ groups [V-O = 1.586 (4) Å] lying in the mirror planes. [ABSTRACT FROM AUTHOR]