Toward Conductive Additive Free Organic Electrode for Lithium-Ion Battery Using Supramolecular Columnar Organization.

With the aim to meet the greatest challenge facing organic batteries, namely the low conductivity of the electrodes, the electrochemical properties of a series of substituted perylene diimides able to form semi-conductive columnar material are investigated. Depending on the substituent group, a strong influence of this group on the reversibility, redox potential but especially on the gravimetric capacity of the electrodes is observed. In the case of substitution by a simple propyl group, the corresponding diimide shows a complete electrochemical activity with only 10% by mass of conductive additive and even shows a half-capacity activity without any additive and without particular electrode engineering. Extensive research has highlighted the intrinsic reactivity of the columnar material but also its perpetual rearrangement during charge/discharge cycles. This study shows that the amount of conductive additive can be significantly reduced by adapting the design of the molecular material and favoring the assembly of redox units in the form of a conductive column.

A PEG-borate ester solid-state polymer electrolyte to fabricate a Li6PS5Cl-rich composite for a Li metal battery.

A Li6PS5Cl-rich composite is prepared using a PEG-borate ester solid-state polymer electrolyte (BSPE). BSPE is a highly accessible compound with high ionic conductivity and excellent electrochemical stability against Li metal. Thereby, the stability of the Li6PS5Cl-rich composite with BSPE improved significantly.

Fundamental insight into the interaction between a lithium salt and an inorganic filler for ion mobility using a synergic theoretical-experimental approach.

The present paper aims at providing a fundamental insight into the interaction between a lithium salt and an inorganic filler in a perspective of lithium mobility. Through a synergistic approach, coupling experimental results and molecular dynamics simulations, the influence of the surface chemical state of the nanosilica Stöber-type on the dissociation of LiTFSI and its impact on the lithium conduction properties are studied. For this purpose, the surface modification of silica nanoparticles was performed by different methods such as calcination, lithiation and capping with organosilane. The impact of the surface modification on the dissociation of the lithium salt is further investigated by electrochemical impedance spectroscopy after impregnation of the material with a defined amount of lithium salt. The combined experimental and in silico analyses of the results, performed for the first time on such systems, allow a detailed understanding of the interaction between the salt and the support and should prove itself useful for the future design of hybrid polymer electrolytes in new generation batteries.

Hybrid Electrolytes Based on Optimized Ionic Liquid Quantity Tethered on ZrO2 Nanoparticles for Solid-State Lithium-Ion Conduction.

This paper describes the simple, highly reproducible, and robust synthesis of a new solid organic/inorganic electrolyte based on the ionic liquid (IL) 1-butyl-3-(carboxyundecyl)imidazolium bis(trifluoromethylsulfonyl)imide tethered to zirconia nanoparticles (15-25 nm) by coordination and named ZrO2@IL. The IL monolayer formation, ensured by two-dimensional solid-state NMR, at the nanoparticles' surface considerably reduces both the IL's consumption and the IL amount at the ZrO2 surface compared to the IL-based hybrid electrolytes reported in the literature. After LiTFSI, used as a lithium source, content optimization (26 wt %), the hybrid exhibits unprecedented stable conductivity passing from 0.6 × 10-4 S.cm-1 to 0.15 × 10-4 S.cm-1, respectively, from 85 °C to room temperature (25 °C). Unlike silica which is commonly adopted for this type of hybrid material, zirconia makes it possible to produce more impact-resistant pellets that are easier to compact, thus being favorable for accurate conductivity studies and battery development by electrode/composite/solid electrolyte layer stacking. The ZrO2@IL/LiTFSI solid hybrid electrolyte's thermal stability (up to 300 °C) and performance make this electrolyte suitable for lithium conduction in all-solid-state batteries.

Reversible Anion Insertion in Molecular Phenothiazine-Based Redox-Active Positive Material for Organic Ion Batteries.

The increasing demand for rechargeable batteries induces the development of greener and better devices. Significant advances have been made in the last decade together with a renewed interest in organic electrode materials. Thus, stable electron-donating organic materials are candidates for "greener" molecular batteries (metal-free). Herein, we report the design of a monomeric p-type N-substituted phenothiazine salt as an efficient anionic host structure working reversibly in a dual-ion cell configuration using lithium as the negative electrode. Investigation of different electrolyte salts, LiClO4 , LiPF6 , and LiTFSI in PC (propylene carbonate), reveals that lithium 4-(10H-phenothiazin-10-yl) benzoate (LiPHB) exhibits a high operating potential (≈3.7 vs. Li+ /Li) corresponding to a one-electron process with a reversible specific capacity of 86 mAh g-1 in a LiClO4 -based electrolyte, exhibiting an extraordinary cycling stability over 500 cycles at 0.2 C. Such impressive results are rendering LiPHB a promising scaffold for developing next-generation molecular organic batteries.

Empowering organic-based negative electrode material based on conjugated lithium carboxylate through molecular design.

In this article, we describe the design and gram-scale synthesis of a new anthracene-based negative electrode material for Li-ion batteries. Based on rational design, featuring a strong electronic delocalization and a long conjugation length, this material has power performance to date unmatched for a conjugated lithium carboxylate, displaying a gravimetric capacity of 150 mAh g-1 at a cycling rate of 20 Li+ /h (10 C) without any electrode engineering. Additionally, to the design, partial solubility of the fully reduced phase may also explain the electrochemical performances obtained at a low and high rate.

Nitroxide supported on nanometric metal oxides as new hybrid catalysts for selective sugar oxidation.

A new series of supported organocatalysts, prepared by a simple method, were used for selective sugar oxidation. This approach is based on the immobilization of a nitroxide derivative through a carboxylic function on nanometric metal oxides (TiO2, Al2O3 and CeO2), allowing the recovery of the catalyst. These hybrid materials were carefully characterized by Diffuse Reflectance FT-IR spectroscopy (DRIFT), ThermoGravimetric Analysis (TGA), X-Ray Diffraction (XRD), Brunauer-Emmet-Teller surface area measurements (B.E.T.), elemental and electrochemical analyses, showing different characteristics and behaviors depending on the nature of the metal oxide used. The activity of the supported nitroxide catalyst was evaluated on methyl α-d-glucoside oxidation, used as model reaction. In all cases, high catalytic activity was highlighted, with up to 25 times less nitroxyl radical required for complete conversion than under homogeneous conditions. The influence of several experimental conditions such as the use of phosphate buffer and recyclability of the catalyst were also investigated.

Poly[µ6-(naphthalene-2,6-di-carboxyl-ato)-bis-(aqua-lithium)].

The title compound, [Li2(C12H6O4)(H2O)2] n , crystallizes with one half of the molecular entities in the asymmetric unit. The second half is gererated by inversion symmetry. The crystal structure has a layered arrangement built from distorted edge-sharing LiO3(OH)2 tetra-hedra parallel to (100), with naphthalenedi-carboxyl-ate bridging the LiO3(OH)2 layers along the [100] direction. Hydrogen bonding between the water molecule and adjacent carboxylate groups consolidates the packing.

Fluorescent Indolizine-b-Cyclodextrin Derivatives for the Detection of Volatile Organic Compounds.

This paper presents the synthesis, the structural determination and the sensing capabilities toward Volatile Organic Compounds (VOCs) of a new class of fluorescent indolizine-cyclodextrin sensors. Two different pathways, both involving bipyridinium ylides and 6-amino-b-cyclodextrin, have been used to carry out the synthesis of these sensors. The macrocycle structures were dominantly established by ¹H-NMR spectra and systematically studied by molecular modelling (MM3, AM1, AM1-COSMO methods). The sensing capabilities of the sensors were evaluated by emission of fluorescence, during the inclusion of the guest (adamantanol or aromatic derivatives) into the cyclodextrin (CD) host cavity. The host/guest complex formation was investigated by formation constant determinations, using experimental methods, coupled with theoretical calculations of formation energies using a specific docking procedure. Both experimental and theoretical results suggest that some compounds would make very attractive sensors for VOC detection. Some compounds could also be taken into consideration as biological markers.