Vying for newer sodium-ion chemistry for rechargeable batteries, Na2FeP2O7 pyrophosphate has been recently unveiled as a 3 V high-rate cathode. In addition to its low cost and promising ...electrochemical performance, here we demonstrate Na2FeP2O7 as a safe cathode with high thermal stability. Chemical/electrochemical desodiation of this insertion compound has led to the discovery of a new polymorph of NaFeP2O7. High-temperature analyses of the desodiated state NaFeP2O7 show an irreversible phase transition from triclinic (P1̅) to the ground state monoclinic (P21/c) polymorph above 560 °C. It demonstrates high thermal stability, with no thermal decomposition and/or oxygen evolution until 600 °C, the upper limit of the present investigation. This high operational stability is rooted in the stable pyrophosphate (P2O7)4– anion, which offers better safety than other phosphate-based cathodes. It establishes Na2FeP2O7 as a safe cathode candidate for large-scale economic sodium-ion battery applications.
The Krebs cycle-derived metabolite itaconate is highly upregulated in inflammatory macrophages and exerts immunomodulatory effects through cysteine modifications on target proteins. The NLRP3 ...inflammasome, which cleaves IL-1β, IL-18, and gasdermin D, must be tightly regulated to avoid excessive inflammation. Here we provide evidence that itaconate modifies NLRP3 and inhibits inflammasome activation. Itaconate and its derivative, 4-octyl itaconate (4-OI), inhibited NLRP3 inflammasome activation, but not AIM2 or NLRC4. Conversely, NLRP3 activation was increased in itaconate-depleted Irg1−/− macrophages. 4-OI inhibited the interaction between NLRP3 and NEK7, a key step in the activation process, and “dicarboxypropylated” C548 on NLRP3. Furthermore, 4-OI inhibited NLRP3-dependent IL-1β release from PBMCs isolated from cryopyrin-associated periodic syndrome (CAPS) patients, and reduced inflammation in an in vivo model of urate-induced peritonitis. Our results identify itaconate as an endogenous metabolic regulator of the NLRP3 inflammasome and describe a process that may be exploited therapeutically to alleviate inflammation in NLRP3-driven disorders.
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•Itaconate and its derivative 4-OI (which generates itaconate) block NLRP3 activation•Itaconate-depleted Irg1−/− BMDMs exhibit increased NLRP3 inflammasome activation•4-OI “dicarboxypropylates” C548 on NLRP3 and blocks the NLRP3-NEK7 interaction•4-OI reduces peritonitis in vivo and blocks IL-1β release from CAPS patient PBMCs
Hooftman et al. reveal a role for the Krebs cycle-derived metabolite itaconate in regulating the NLRP3 inflammasome. Itaconate specifically blocks NLRP3 inflammasome activation by reducing the NLRP3-NEK7 interaction, likely due to modification of C548 on NLRP3. Furthermore, itaconate inhibits IL-1β release from cells isolated from patients with the NLRP3-mediated disease CAPS.
The magnetic structure and properties of polycrystalline NaFePO4 polymorphs, maricite and triphylite, both derived from the olivine structure type, have been investigated using magnetic ...susceptibility, heat capacity, and low-temperature neutron powder diffraction. These NaFePO4 polymorphs assume orthorhombic frameworks (space group No. 62, Pnma), built from FeO6 octahedral and PO4 tetrahedral units having corner-sharing and edge-sharing arrangements. Both polymorphs demonstrate antiferromagnetic ordering below 13 K for maricite and 50 K for triphylite. The magnetic structure and properties are discussed considering super- and supersuperexchange interactions in comparison to those of triphylite-LiFePO4.
The monoclinic phase of Na4Ti5O12 (M-Na4Ti5O12) has been investigated as a potential sodium-ion battery anode material. In contrast to the previously investigated trigonal phase (T-Na4Ti5O12), ...M-Na4Ti5O12 has continuous two-dimensional (2D) channels with partially occupied Na sites, providing broader pathways and more space for the intercalation of excess sodium. Electrochemical measurements show that it exhibits a comparable or higher reversible capacity than T-Na4Ti5O12. Neutron powder diffraction reveals the preferred sites and occupancies of the excess sodium. In situ synchrotron X-ray diffraction under electrochemical cycling shows that the crystal lattice undergoes strongly anisotropic volume changes during cycling.
Atomic-scale disorder plays an important role in the chemical and physical properties of oxide materials. The structural flexibility of pyrochlore-type oxides allows for crystal-chemical engineering ...of these properties. Compositional modification can push pyrochlore oxides toward a disordered defect-fluorite structure with anion Frenkel pair defects that facilitate oxygen migration. The local structure of the long-range average cubic defect-fluorite was recently claimed to consist of randomly arranged orthorhombic weberite-type domains. In this work, we show, using low-temperature neutron total-scattering experiments, that this is not the case for Zr-rich defect-fluorites. By analyzing data from the pyrochlore/defect-fluorite Y2Sn2–x Zr x O7 series using a combination of neutron pair distribution function and big-box modelling, we have differentiated and quantified the relationship between anion sub-lattice disorder and Frenkel defects. These details directly influence the energy landscape for oxygen migration and are crucial for simulations and design of new materials with improved properties.
We positively identified and quantified the solid-state phases involved in the carbonation/decarbonation cycle of Na
ZrO
when used for carbon capture. Previous work had only qualitatively inferred ...the phases present using diffraction pattern matching and thermogravimetric analysis. Here, we used the Rietveld-refinement method to analyze synchrotron X-ray and neutron powder diffraction data from samples treated
. We then confirmed and extended our findings by
diffraction using a purpose-built gas-flow apparatus. This allowed us to resolve discrepancies in the earlier literature concerning which phases are present during the carbonation and regeneration processes. A key finding is the simultaneous presence of the monoclinic and tetragonal phases of ZrO
and that the "metastable" tetragonal phase is favored by smaller particles and can reincorporate into the bulk but the stable monoclinic phase does not. The result will help optimize the cycling of Na
ZrO
.
The crystal and magnetic structures and properties of the monoclinic form of the iron hydroxysulfate FeOHSO4 were investigated by magnetometry and neutron powder diffraction. The space group C2/c was ...confirmed, and the proton position was located close to that predicted by ab initio calculations. The collinear antiferromagnetic k(0,0,0) structure forming below the Néel temperature T N ∼ 125 K is described by the C2′/c′ (No. 15.89) magnetic space group, with the moments along the b axis. Overall, FeOHSO4 is isostructural to FeSO4F in terms of both the crystal and magnetic structures.
Li3Co2SbO6 is found to adopt two highly distinct structural forms: a pseudohexagonal (monoclinic C2/m) layered O3-LiCoO2 type phase with “honeycomb” 2:1 ordering of Co and Sb, and an orthorhombic ...Fddd phase, isostructural with Li3Co2TaO6 but with the addition of significant Li/Co ordering. Pure samples of both phases can be obtained by conventional solid-state synthesis via a precursor route using Li3SbO4 and CoO, by controlling particle size, initial lithium excess, and reaction time. Both phases show relatively poor performance as lithium-ion battery cathode materials in their as-made states, but complex and interesting low-temperature magnetic properties. The honeycomb phase is the first of its type to show A-type antiferromagnetic order (ferromagnetic planes, antiferromagnetically coupled) below T N = 14 K. Isothermal magnetization and in-field neutron diffraction below T N show clear evidence for a metamagnetic transition at H ≈ 0.7 T to three-dimensional ferromagnetic order. The orthorhombic phase orders antiferromagnetically below T N = 112 K and then undergoes two more transitions at 80 and 60 K. Neutron diffraction data show that the ground state is incommensurate.
Carbon-encapsulated transitional metal sulfides are considered as a promising anode material candidate for lithium ion batteries. Herein, a simple process is developed to synthesize 3D ...orostachys-like cobalt sulfides/C composites. This process is associated with the rational design of metal organic frameworks (MOFs) and subsequent in-situ sulfurization. Benefit from its unique structures, this novel 3D orostachys-like cobalt sulfides@C composites delivers an excellent charge capacity of 791 mAh g−1 after 100 cycles at 0.2 A g−1 as well as high stability of 667 mA g−1 after 700 cycles at 1 A g−1. Pseudocapacitive behaviors enhanced the electrochemical performance of 3D orostachys-like cobalt sulfides@C composites.
Scheme illustrating the benefit of hierarchical micro/nano-structure of Co1-xS/C composites. Display omitted
•Novel orostachys-like metal-organic frameworks were synthesized.•Cobalt sulfide nanoparticles uniformly embedded in hierarchical porous carbon network.•Several features of the hybrids lead to excellent lithium storage performance.•Pseudocapacitive behaviors enhanced the electrochemical performance of the hybrids.
The exceptional oxide ionic conductivity of the high-temperature phase of bismuth oxide gives rise to a characteristic “quasielastic” broadening of its neutron scattering spectrum. We show that the ...oscillating form of this broadening can be fit using a modified version of a jump-diffusion model previously reserved for liquid ionic conductors. Fit parameters include a quantitative jump distance and a semiquantitative diffusion coefficient. In the case presented here, the results show that diffusion is isotropic (liquid-like) even though some directions present shorter oxygen–vacancy distances, an insight corroborated by computational dynamics simulations. More broadly, the results show for the first time that quasielastic neutron scattering can be directly analyzed to yield quantitative insights into the atomic-scale mechanisms of solid-state ionic conduction, even when the diffusing species is a coherent neutron scatterer such as oxygen. This shows its power as a tool for studying functional solid-state materials, notably for solid-oxide fuel cells and, potentially, lithium-ion batteries.
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