Na Zr Si PO Solid Electrolyte Membrane for High-Performance Seawater Battery.

Seawater batteries (SWBs) have gained tremendous interest in the electrochemical energy storage research field because of their low cost, natural abundance, and potential use for long-duration energy storage. Advancing a SWB to demonstration projects is plagued by the poor electrochemical performance stemming from the poor interfaces of the solid electrolyte (SE), as well as the structural and chemical instabilities and sluggish ionic transport properties. In this study, the anode compartment of a surrogate SWB is constructed with a Na | SE | hard carbon configuration, and tailored dopants are introduced into the Nasicon-type Na Zr Si PO (NZSP) SE membrane.

Differences in the Interfacial Mechanical Properties of Thiophosphate and Argyrodite Solid Electrolytes and Their Composites.

Interfacial mechanics are a significant contributor to the performance and degradation of solid-state batteries. Spatially resolved measurements of interfacial properties are extremely important to effectively model and understand the electrochemical behavior. Herein, we report the interfacial properties of thiophosphate (LiPS)- and argyrodite (LiPSCl)-type solid electrolytes.

A lightweight thermally insulating and moisture-stable composite made of hollow silica particles.

Thermal insulation materials are highly desirable for several applications ranging from building envelopes to thermal energy storage systems. A new type of low-cost insulation material called hollow silica particles (HSPs) was recently reported. The present work presents an HSP-based stand-alone composite that has very low thermal conductivity and is highly stable to moisture.

Operando Analysis of Gas Evolution in TiNbO (TNO)-Based Anodes for Advanced High-Energy Lithium-Ion Batteries under Fast Charging.

TiNbO (TNO) is regarded as one of the promising next-generation anode materials for lithium-ion batteries (LIBs) due to its high rate capabilities, higher theoretical capacity, and higher lithiation voltage. This enables the cycling of TNO-based anodes under extreme fast charging (XFC) conditions with a minimal risk of lithium plating compared to that of graphite anodes. Here, the gas evolution in real time with TNO-based pouch cells is first reported via operando mass spectrometry.

Dynamics of Emim in [Emim][TFSI]/LiTFSI Solutions as Bulk and under Confinement in a Quasi-liquid Solid Electrolyte.

Quasi-liquid solid electrolytes are a promising alternative for next-generation Li batteries. These systems combine the safety of solid electrolytes with the desired properties of liquids and are typically formed by solutions of Li salts in ionic liquids incorporated into solid matrices. Here, we present a fundamental understanding of the transport properties in solutions of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][TFSI]), either in bulk form or incorporated in a boron nitride (BN) matrix.

Directed Assembly of Multi-Walled Nanotubes and Nanoribbons of Amino Acid Amphiphiles Using a Layer-by-Layer Approach.

Monodisperse unilamellar nanotubes (NTs) and nanoribbons (NRs) were transformed to multilamellar NRs and NTs in a well-defined fashion. This was done by using a step-wise approach in which self-assembled cationic amino acid amphiphile (AAA) formed the initial NTs or NRs, and added polyanion produced an intermediate coating. Successive addition of cationic AAA formed a covering AAA layer, and by repeating this layer-by-layer (LBL) procedure, multi-walled nanotubes (mwNTs) and nanoribbons were formed.

Synthesizing High-Capacity Oxyfluoride Conversion Anodes by Direct Fluorination of Molybdenum Dioxide (MoO ).

High-capacity metal oxide conversion anodes for lithium-ion batteries (LIBs) are primarily limited by their poor reversibility and cycling stability. In this study, a promising approach has been developed to improve the electrochemical performance of a MoO anode by direct fluorination of the prelithiated MoO . The fluorinated anode contains a mixture of crystalline MoO and amorphous molybdenum oxyfluoride phases, as determined from a suite of characterization methods including X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy, and scanning transmission electron microscopy.

Eutectic Synthesis of the P2-Type NaFeMnO Cathode with Improved Cell Design for Sodium-Ion Batteries.

An engaging area of research in sodium-ion batteries (SIBs) has been focusing on discovery, design, and synthesis of high-capacity cathode materials in order to boost energy density to levels close enough to that of state-of-the-art lithium-ion batteries. Of particular interest, P2-type layered oxide, NaFeMnO, has been researched as a potential cathode in SIBs based on its high theoretical capacity of 260 mA h/g and use of noncritical materials. However, the reported synthesis methods are not only complex and energy-demanding but also often yield inhomogeneous and impure materials with capacities less than 200 mA h/g under impractical test conditions.

Probing the Li Ti O Interface Upon Lithium Uptake by Operando Small Angle Neutron Scattering.

The formation of a solid-electrolyte interphase (SEI) on the surface of Li Ti O (LTO) has become a highly controversial topic, with arguments for it and against it. However, prior studies supporting the formation of an SEI layer have typically suggested that a layer forms upon cycling of a cell, although the layer is probed after disassembling. In this study, cubic mesostructured LTO is synthesized with crystallite domain sizes between 3 and 4 nm and uniform pores with diameters ≤8 nm.

Fluorination of MXene by Elemental F as Electrode Material for Lithium-Ion Batteries.

The transformation of MXene sheets into TiOF 2D sheets with superior electrochemical performance was developed. MXene synthesized from Ti AlC was fluorinated for 3, 6, and 24 h, respectively, by means of a direct fluorination process. Exposure of MXene powder to elemental fluorine for 3 h induced the formation of CF groups and TiF on the surface, which have beneficial effects on the electrochemical performance.

Catanionic and chain-packing effects on surfactant self-assembly in the ionic liquid ethylammonium nitrate.

Hypothesis: Micelle formation, particularly the formation of compact, globular micelles in the high ionic strength environment of an ionic liquid, seems to be at odds with the principle of opposing forces and the concept of the surfactant packing parameter. Here we examine how interactions between polar head-groups, with solvent ions, and chain packing affect self-assembly structure in ionic liquids.

Experiments: The self-assembly of pure cationic and anionic surfactants, their catanionic mixtures, and the effect of the cosurfactant tetradecanol in the ionic liquid ethylammonium nitrate (EAN) is investigated by small-angle neutron scattering (SANS).

Nanoscale organization in the fluorinated room temperature ionic liquid: Tetraethyl ammonium (trifluoromethanesulfonyl)(nonafluorobutylsulfonyl)imide.

Fluorinated Room Temperature Ionic Liquids (FRTILs) are a branch of ionic liquids that is the object of growing interest for a wide range of potential applications, due to the synergic combination of specifically ionic features and those properties that stem from fluorous tails. So far limited experimental work exists on the micro- and mesoscopic structural organization in this class of compounds. Such a work is however necessary to fully understand morphological details at atomistic level that would have strong implications in terms of bulk properties.

Ion Dynamics in Ionic-Liquid-Based Li-Ion Electrolytes Investigated by Neutron Scattering and Dielectric Spectroscopy.

A detailed understanding of the diffusion mechanisms of ions in pure and doped ionic liquids remains an important aspect in the design of new ionic-liquid electrolytes for energy storage. To gain more insight into the widely used imidazolium-based ionic liquids, the relationship between viscosity, ionic conductivity, diffusion coefficients, and reorientational dynamics in the ionic liquid 3-methyl-1-methylimidazolium bis(trifluoromethanesulfonyl)imide (DMIM-TFSI) with and without lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) was examined. The diffusion coefficients for the DMIM cation and the role of ion aggregates were investigated by using the quasielastic neutron scattering (QENS) and neutron spin echo techniques.

Methyl quantum tunneling in ionic liquid [DMIm][TFSI] facilitated by Bis(trifluoromethane)sulfonimide lithium salt.

We probe, for the first time, quantum tunneling in the methyl groups of the ionic liquid [DMIm][TFSI] facilitated by the presence of Bis(trifluoromethane)sulfonimide lithium salt. The observation of tunneling is made possible by crystallization, rather than vitrification, of [DMIm][TFSI] at low temperature. Neutron scattering measurements detect quantum tunneling excitations at ~27 μeV at temperatures below 30 K in the presence of LiTFSI at a concentration of 1 mol/kg, but not in salt-free [DMIm][TFSI].

Tuning the solution organization of cationic polymers through interactions with bovine serum albumin.

The interactions of bovine serum albumin (BSA) with aggregates of cationic polymers, i.e. quaternized poly(chloromethyl styrene) chains (QIm-PCMS), in aqueous solutions are investigated using small angle neutron scattering on length scales relevant to the size of BSA.

Mesoscopic organization in ionic liquids.

We discuss some published results and provide new observations concerning the high level of structural complexity that lies behind the nanoscale correlations in ionic liquids (ILs) and their mixtures with molecular liquids. It turns out that this organization is a consequence of the hierarchical construction on both spatial (from ångström to several nanometer) and temporal (from fraction of picosecond to hundreds of nanosecond) scales, which requires joint use of experimental and computational tools.

Direct experimental observation of mesoscopic fluorous domains in fluorinated room temperature ionic liquids.

Fluorinated room temperature ionic liquids (FRTILs) represent a class of solvent media that are attracting great attention due to their IL-specific properties as well as features stemming from their fluorous nature. Medium-to-long fluorous tails constitute a well-defined apolar moiety in the otherwise polar environment. Similarly to the case of alkyl tails, such chains are expected to result in the formation of self-assembled fluorous domains.

Synthesis of Dispersible Mesoporous Nitrogen-Doped Hollow Carbon Nanoplates with Uniform Hexagonal Morphologies for Supercapacitors.

In this study, dispersible mesoporous nitrogen-doped hollow carbon nanoplates have been synthesized as a new anisotropic carbon nanostructure using gibbsite nanoplates as templates. The gibbsite-silica core-shell nanoplates were first prepared before the gibbsite core was etched away. Dopamine as carbon precursor was self-polymerized on the hollow silica nanoplates surface assisted by sonification, which not only favors a homogeneous polymer coating on the nanoplates but also prevents their aggregation during the polymerization.

Small-angle neutron scattering and molecular dynamics structural study of gelling DNA nanostars.

DNA oligomers with properly designed sequences self-assemble into well defined constructs. Here, we exploit this methodology to produce bulk quantities of tetravalent DNA nanostars (each one composed of 196 nucleotides) and to explore the structural signatures of their aggregation process. We report small-angle neutron scattering experiments focused on the evaluation of both the form factor and the temperature evolution of the scattered intensity at a nanostar concentration where the system forms a tetravalent equilibrium gel.

Multidimensional operando analysis of macroscopic structure evolution in lithium sulfur cells by X-ray radiography.

Lithium sulfur cells are the most promising candidate for the post lithium-ion battery era. Their major drawback is rapid capacity fading attributed to the complex electrochemical processes during charge and discharge which are not known precisely. Here we present for the first time a multidimensional operando measurement by combining X-ray radiography with impedance spectroscopy while galvanostatically charging and discharging a lithium sulfur cell.

Microwave-assisted synthesis of high-voltage nanostructured LiMn1.5Ni0.5O4 spinel: tuning the Mn3+ content and electrochemical performance.

The LiMn1.5Ni0.5O4 spinel is an important lithium ion battery cathode material that has continued to receive major research attention because of its high operating voltage (∼4.

Epitaxial deposition of silver ultra-fine nano-clusters on defect-free surfaces of HOPG-derived few-layer graphene in a UHV multi-chamber by in situ STM, ex situ XPS, and ab initio calculations.

The growth of three-dimensional ultra-fine spherical nano-particles of silver on few layers of graphene derived from highly oriented pyrolytic graphite in ultra-high vacuum were characterized using in situ scanning tunneling microscopy (STM) in conjunction with X-ray photoelectron spectroscopy. The energetics of the Ag clusters was determined by DFT simulations. The Ag clusters appeared spherical with size distribution averaging approximately 2 nm in diameter.