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Investigation of sulphate hydride anti-perovskite as solid electrolyte
No full textInternational audienceOver the last decade, anti-perovskites have drawn significant attention as potential solid-electrolytes for solid-state batteries. Due to the increase in consumption of lithium, there has been a push towards next generation batteries, including sodium-ion batteries. The first representative of the material class of sulphate hydride anti-perovskites, Na3SO4H, was synthesized by solid-state methods as a possible electrolyte for sodium solid-state batteries. Structural characterization confirms the results reported in literature with P4/nmm space group Thermal measurements (DSC and TGA) reveal the stability of the material up to 633 K with H2 release beginning shortly after. Here were report the first electrochemical measurements of this new sulphate hydride anti-perovskite with room temperature conductivity of 4.0 × 10−7 S/cm. Similarly, the electronic conductivity was also measured by Direct Current (DC) experiments to understand a non-linear Arrhenius plot of the conductivity. From the EIS and DC measurements, it is suggested that the electronic and ionic conductivities of this material fall in the same range at room temperature. Upon heating, the material becomes a mainly ionic conductor, explaining the change in the activation energy values in the Arrhenius plot (0.83 eV at low T and 0.24 eV at high T). Solid-state NMR hints at defects in the structure that correspond to Na1 and Hb-c-d dynamics
Real-time monitoring of Ti-Nb-Ta-Zr and commercially pure Ti interaction with H2O2 using atomic force microscopy and atomic emission spectroelectrochemistry
No full textInternational audienceThis study offers a new approach to analyze surface behavior of titanium biomaterials during their exposure to the H2O2-enriched fluid which simulates post-operative inflammatory conditions. In this work in situ AFM and AESEC tests were exploited to study the origin of initial inflammatory-induced degradation for commercially pure Ti (CP-Ti) and Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy. Overall results indicate that initial interaction between H2O2 and TNTZ surface results only in dissolution of the alloy, while for CP-Ti both oxide formation and dissolution give important contribution to the degradation process. Proposed methodology yields insight into the origin of corrosion properties registered during standard electrochemical tests that are used to evaluate biomaterials
An alternative polymer material to PVDF binder and carbon additive in Li‐ion battery positive electrode
No full textInternational audienceLi-ion battery performance relies fundamentally on modulation at the microstructure and interface levels of the composite electrodes. Correspondingly, the binder is a crucial component for mechanical integrity of the electrode, serving to interconnect the active material and conductive additive and to firmly attach this composite to the current collector. However, the commonly used poly(vinylidenefluoride) (PVDF) binder presents several limitations, including the use of toxic solvent during processing, a low electrical conductivity which for compensation requires the addition of carbon black, and weak interactions with active materials and collectors. This study investigates Poly(3,4-ethylenedioxythiophene):poly[(4-styrenesulfonyl) (trifluoromethylsulfonyl) imide] (PEDOT:PSSTFSI) as an alternative binder and conductive additive, in replacement of both PVDF and carbon black, in Li-ion batteries with LiFe 0.4 Mn 0.6 PO 4 at the positive electrode. Complex PEDOT:PSSTFSI significantly improves the electronic conductivity and lithium diffusion coefficient within the electrode, in comparison to standard PVDF binder and carbon black. This enhances significantly the electrochemical performance at high C-rates and for high active mass loading electrodes. Furthermore, an excellent long-range cyclability is achieved
GRID1/GluD1 homozygous variants linked to intellectual disability and spastic paraplegia impair mGlu1/5 receptor signaling and excitatory synapses
No full textInternational audienceThe ionotropic glutamate delta receptor GluD1, encoded by the GRID1 gene, is involved in synapse formation, function, and plasticity. GluD1 does not bind glutamate, but instead cerebellin and D-serine, which allow the formation of trans-synaptic bridges, and trigger transmembrane signaling. Despite wide expression in the nervous system, pathogenic GRID1 variants have not been characterized in humans so far. We report homozygous missense GRID1 variants in five individuals from two unrelated consanguineous families presenting with intellectual disability and spastic paraplegia, without (p.Thr752Met) or with (p.Arg161His) diagnosis of glaucoma, a threefold phenotypic association whose genetic bases had not been elucidated previously. Molecular modeling and electrophysiological recordings indicated that Arg161His and Thr752Met mutations alter the hinge between GluD1 cerebellin and D-serine binding domains and the function of this latter domain, respectively. Expression, trafficking, physical interaction with metabotropic glutamate receptor mGlu1, and cerebellin binding of GluD1 mutants were not conspicuously altered. Conversely, upon expression in neurons of dissociated or organotypic slice cultures, we found that both GluD1 mutants hampered metabotropic glutamate receptor mGlu1/5 signaling via Ca 2+ and the ERK pathway and impaired dendrite morphology and excitatory synapse density. These results show that the clinical phenotypes are distinct entities segregating in the families as an autosomal recessive trait, and caused by pathophysiological effects of GluD1 mutants involving metabotropic glutamate receptor signaling and neuronal connectivity. Our findings unravel the importance of GluD1 receptor signaling in sensory, cognitive and motor functions of the human nervous system
Safety Aspects of Sodium-Ion Batteries: Prospective Analysis from First Generation Towards More Advanced Systems
No full textInternational audienceAfter an introductory reminder of safety concerns pertaining to early rechargeable battery technologies, this review discusses current understandings and challenges of advanced sodium-ion batteries. Sodium-ion technology is now being marketed by industrial promoters who are advocating its workable capacity, as well as its use of readily accessible and cheaper key cell components. Often claimed to be safer than lithium-ion cells, currently only limited scientifically sound safety assessments of sodium-ion cells have been performed. However, the predicted sodium-ion development roadmap reveals that significant variants of sodium-ion batteries have entered or will potentially enter the market soon. With recent experiences of lithium-ion battery failures, sodium-ion battery safety management will constitute a key aspect of successful market penetration. As such, this review discusses the safety issues of sodium-ion batteries, presenting a twofold innovative perspective: (i) in terms of comparison with the parent lithium-ion technology making use of the same working principle and similar flammable non-aqueous solvent basis, and (ii) anticipating the arrival of innovative sub-chemistries at least partially inspired from successive generations of lithium-ion cells. The authors hope that the analysis provided will assist concerned stakeholders in the quest for safe marketing of sodium-ion batteries.</div
BaCoO 2 with Tetrahedral Cobalt Coordination: The Missing Element to Understand Energy Storage and Conversion Applications in BaCoO 3−δ -Based Materials
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Hot ion implantation for creating dense NV ensemble near the diamond surface
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Status of CVD Diamond Growth dnd Engineering for High-End Applications
No full textInternational audienceDiamond is a transparent wide band gap material with outstanding optical and electronic properties that are attracting a lot of attention for the development of the next generation of devices. But high-end applications require dedicated solid-state material platforms with unprecedented control over quality, purity and doping. Indeed single crystal diamond provides an ideal host material to incorporate different types of impurities that can drastically modify its properties. The use of dopants such as boron can for example allow tuning the electrical conductivity of the film up to the metallic conduction which could allow to produce highly boron doped substrates and develop vertical components whose design and architecture for the realization of more complex function is simpler. Beyond the crucial aspect of high doping levels, which is essential for the development of substrates for power electronics, it is also important to be able to produce diamond films with a low density of extended defects, especially dislocations. This aspect is even more challenging to control as the surface area of growing diamonds is significant.In this presentation, in a first part, we will focus more specifically on the production aspects of doped monocrystalline diamond films by chemical vapor deposition assisted by microwave plasma with boron highlighting all the constraints inherent to the targeted field of application. Particular attention will be paid to showing the plasma conditions which it is essential to maintain in order to obtain a sufficiently thick and doped film leading to on state resistances compatible with their use in vertical components. It will be shown in particular the importance of the gas composition to inject high microwave power allowing coupling high material quality with high growth rate. In a second part, special attention will be paid to the development of growth strategies allowing limiting the propagation of dislocations in diamond during growth [1]. We will demonstrate that shaping the substrate before growth can modify the propagation direction of dislocations and thus limit their emergence at the surface. and that this technique remains applicable regardless of the dimensions of the growing substrate. A reduction in dislocation density of nearly 2 orders of magnitude has thus been achieved [2], paving the way for the development of large-size substrates that should enable the development of electronic components.References: [1] Tallaire et al, Advanced Materials, 29, 1604823 (2017) [2] Mehmel et al, Appl. Phys. Lett. 118, 061901 (2021
Unlocking Auxetic Behavior in Recyclable Thermosetting Foams Enabled by Dynamic Disulfide Cross-linking Strategy
No full textInternational audienceAuxetic foams with a negative Poisson's ratio (NPR) have attracted considerable attention in material engineering due to their outstanding performance in seismic and energy absorption. Nevertheless, thermoplastic auxetic foams are compromised by weak non-covalent crosslinking that diminishes the mechanical strength and durability of foams. Conversely, thermosetting foams with chemical crosslinking, although mechanically robust, face challenges in elaborating auxetic structure and in achieving recyclability. Herein, we propose an alternative approach to tackle this dilemma by incorporating dynamic disulfide bonds into the polymer network for preparing a thermosetting polyurethane foam with covalent adaptable network. By leveraging the unidirectional multi-effect compression technique, we have induced the topological network reorganization of foam, transforming the initial circular open-cell structure into a re-entrant cell structure. This structural transformation endows the foam with stable NPR capability, achieving a minimum Poisson's ratio value of -0.4 within 30% compressive strain. Benefiting from its reinforced network structure, the foam also demonstrates high compressive strength (6.47 MPa) and tensile strength (1.67 MPa). Furthermore, it is recyclable and can be recompressed into thermosetting films. This work offers a straightforward approach to make auxetic thermosetting foams with good mechanical and recyclable properties, which is interesting for the development of high-performance auxetic materials
Post-metallation functionalization of the [(C^C)Au(P^P)]+ scaffold through a hydrothiolation reaction
No full textInternational audienceComplex 1 [(C^C)Au(dppv)]PF6 (dppv = cis-1,2-diphenylphosphinoethylene) is reported to react efficiently and selectively with aliphatic and aromatic thiols in the presence of a base. This methodology enables the smooth introduction..