Redox-Active Halide Catholytes for Enhanced Energy Density in Solid-State Sodium Batteries.

Sodium-based all-solid-state batteries (ASSBs) are a promising technology for grid-scale energy storage applications due to their theoretically low cost and high energy density. However, state-of-the-art ASSB cathodes are often in the form of heterogeneous composites with 20-40% inactive solid catholyte, which undermines the energy density benefits of the solid-state format. Furthermore, solid catholytes are often comprised of cost-prohibitive, rare metals.

A New Class of Oxyhalide Solid Electrolytes NaNbClO for Solid-state Sodium Batteries.

Sodium-based batteries are gaining momentum due to the abundance and lower cost of sodium compared to lithium. Solid-state sodium batteries can also provide further safety advantages. However, sodium-based solid-state electrolytes (SSEs) that meet all the rigorous requirements, such as high ionic conductivity, oxidative stability with the cathode, and ease of processability, are lacking.

Unveiling the Influence of Water Molecules on the Structural Dynamics of Prussian Blue Analogues.

3D-framework Prussian blue analogues (PBAs) are appealing as a cost-effective, sustainable cathodes for Na-ion batteries. However, the aqueous-based synthesis of PBAs inherently introduces three different forms of water molecules (surface, interstitial and crystal) into the structure. Removal of water molecules causes phase transformation from monoclinic (M) to rhombohedral (R).

Effects of Coprecipitation Conditions on the Electrochemical Properties of Cobalt-Free LiNiMnAlO Cathodes.

Commercializing high-nickel, cobalt-free cathodes, such as LiNiMnAlO (NMA-90), hinges on effectively incorporating Al during the hydroxide coprecipitation reaction. However, Al coprecipitation is nontrivial as Al possesses unique precipitation properties compared to Ni and Mn, which impact the final precursor morphology and consequently the cathode properties. In this study, the nuance of Al coprecipitation and its influence on the cycling stability of NMA with increasing Al content is elucidated.

Structure and Properties of NaS-SiS-PS-NaPO Glassy Solid Electrolytes.

In the development of sodium all-solid-state batteries (ASSBs), research efforts have focused on synthesizing highly conducting and electrochemically stable solid-state electrolytes. Glassy solid electrolytes (GSEs) have been considered very promising due to their tunable chemistry and resistance to dendrite growth. For these reasons, we focus here on the atomic-level structures and properties of GSEs in the compositional series (0.

Formation of Stable Radicals by Mechanochemistry and Their Application for Magic Angle Spinning Dynamic Nuclear Polarization Solid-State NMR Spectroscopy.

High-field magic angle spinning (MAS) dynamic nuclear polarization (DNP) is becoming a common technique for improving the sensitivity of solid-state nuclear magnetic resonance (SSNMR) by the hyperpolarization of nuclear spins. Recently, we have shown that gamma irradiation is capable of creating long-lived free radicals that are amenable to MAS DNP in quartz and a variety of organic solids. Here, we demonstrate that ball milling is able to generate millimolar concentrations of stable radical species in diverse materials such as polystyrene, cellulose, borosilicate glass, and fused quartz.

Mitigating Sodium Ordering for Enhanced Solid Solution Behavior in Layered NaNiO Cathodes.

The O-type layered nickel oxides suffer from undesired cooperative Jahn-Teller distortion stemming from Ni ions and undergo multiple biphasic structural transformations during the insertion/extraction of large Na ions, posing a significant challenge to stabilize the structural integrity. We present here a systematic investigation of the impact of substituting 5 % divalent (Mg) or trivalent (Al or Co) ions for Ni to alleviate Naion ordering and perturb the Jahn-Teller effect to enhance structural stability. We gauge a fundamental understanding of the Mg-O and Na-O or Mg-O-Na bonding interactions, noting that the ionicity of the Mg-O bond deshields the electronic cloud of oxygen from Na ions.

Polycarbonate-Based Solid-Polymer Electrolytes for Solid-State Sodium Batteries.

Solid-polymer electrolytes comprised of polypropylene carbonate (PPC) and varied sodium bis(fluorosulfonyl)imide (NaFSI) salt concentrations are investigated for implementation as a conductive solid polymer electrolyte into solid-state cathode composites utilizing a sodium-layered oxide active material. The ionic conductivity generally increases with NaFSI salt content, reaching ≈1 mS cm at 80 °C at the highest salt concentration (PPC:NaFSI = 0.5:1).

Scalable Glass-Fiber-Polymer Composite Solid Electrolytes for Solid-State Sodium-Metal Batteries.

In this work, we report a method for producing a thin (<50 μm), mechanically robust, sodium-ion conducting composite solid electrolyte (CSE) by infiltrating the monomers of polyethylene glycol diacrylate (PEGDA) and polyethylene glycol (PEG) and either NaClO or NaFSI salt into a silica-based glass-fiber matrix, followed by an UV-initiated in situ polymerization. The glass fiber matrix provided mechanical strength to the CSE and enabled a robust, self-supporting separator. This strategy enabled the development of CSEs with high loadings of PEG as a plasticizer to enhance the ionic conductivity.

NaPON Doping of NaPS Glass and Its Effects on the Structure and Properties of Mixed Oxy-Sulfide-Nitride Phosphate Glass.

The preparation, properties, and short-range order (SRO) structures of glasses in the series (1-)[2/3NaS + 1/3PS] + [1/3NaS + 2/3NaPON] = NaPSON, where 0 ≤ ≤ 0.5 (NaPSON), are reported on. In this study, these mixed oxy-sulfide-nitride (MOSN) glasses were prepared by adding the nitrided material NaPON; = 0.

An electrochemically stable homogeneous glassy electrolyte formed at room temperature for all-solid-state sodium batteries.

All-solid-state sodium batteries (ASSSBs) are promising candidates for grid-scale energy storage. However, there are no commercialized ASSSBs yet, in part due to the lack of a low-cost, simple-to-fabricate solid electrolyte (SE) with electrochemical stability towards Na metal. In this work, we report a family of oxysulfide glass SEs (NaPSO, where 0 < x ≤ 0.

Synthesis, Short-Range Order Structure, and Thermal Properties of Mixed Oxy-sulfide Nitride (MOSN) Glasses.

Nitrogen doping has been shown to greatly improve the stability of solid electrolyte (SE) materials at the anode and cathode interfaces in all solid-state batteries (ASSBs) as widely demonstrated by the LiPON family of compositions. In an effort to expand the use of nitrogen in SEs, in this study, mixed oxy-sulfide nitride (MOSN) glasses were prepared by direct ammonolysis of the sodium oxy-sulfide phosphate NaPSO (NaPSO) glass series to understand the combined effects that oxygen and sulfur have on the incorporation of nitrogen. The short-range order (SRO) structures of the NaPSON (NaPSON) glasses were investigated with Raman and infrared (IR) spectroscopies to understand the effect that nitrogen has in the glass structure.

New Amorphous Oxy-Sulfide Solid Electrolyte Material: Anion Exchange, Electrochemical Properties, and Lithium Dendrite Suppression via Interfacial Modification.

Glassy sulfide materials have been considered as promising candidates for solid-state electrolytes (SSEs) in lithium and sodium metal (LM and SM) batteries. While much of the current research on lithium glassy SSEs (GSSEs) has focused on the pure sulfide binary LiS + PS system, we have expanded these efforts by examining mixed-glass-former (MGF) compositions which have mixtures of glass formers, such as P and Si, which allow melt-quenching synthesis under ambient pressure and therefore the use of grain-boundary-free SSEs. We have doped these MGF compositions with oxygen to improve the chemical, electrochemical, and thermal properties of these glasses.

Formation of Size and Density Controlled Nanostructures by Galvanic Displacement.

Gold (Au) and copper (Cu)-based nanostructures are of great interest due to their applicability in various areas including catalysis, sensing and optoelectronics. Nanostructures synthesized by the galvanic displacement method often lead to non-uniform density and poor size distribution. Here, density and size-controlled synthesis of Au and Cu-based nanostructures was made possible by galvanic displacement with limited exposure to hydrofluoric (HF) acid and the use of surfactants like L-cysteine (L-Cys) and cetyltrimethylammonium bromide (CTAB).

Lithium Thiosilicophosphate Glassy Solid Electrolytes Synthesized by High-Energy Ball-Milling and Melt-Quenching: Improved Suppression of Lithium Dendrite Growth by Si Doping.

Due to the volatility of PS, the ambient pressure synthesis of LiS + PS (LPS) has been limited to planetary ball-milling (PBM). To utilize PBM of LPS to generate a solid electrolyte (SE), the as-synthesized powder sample must be pressed into pellets, and as such the presence of as-pressed grain boundaries in the SE cannot be avoided. To eliminate the grain boundaries, LPS doped with SiS has been studied because SiS lowers the vapor pressure of the melt and promotes strong glass formation, which in combination allows for greater ease in synthesis.

Liquid Metal-Elastomer Soft Composites with Independently Controllable and Highly Tunable Droplet Size and Volume Loading.

Soft composites are critical for soft and flexible materials in energy harvesting, actuators, and multifunctional devices. One emerging approach to create multifunctional composites is through the incorporation of liquid metal (LM) droplets such as eutectic gallium indium (EGaIn) in highly deformable elastomers. The microstructure of such systems is critical to their performance; however, current materials lack control of particle size at diverse volume loadings.