Abstract: A high-performance electrochemically active sodium molten salt catholyte enables a dramatic reduction in molten sodium battery operating temperature from near 300° C. to less than 120° C. As an example, stable electrochemical cycling was demonstrated in a high voltage (3.65 V) sodium battery comprising a sodium iodide-gallium chloride (NaI—GaCl3) molten salt catholyte for over 8 months at 110° C. The combination of high voltage, stable cycling behavior, and practical current densities supported by a molten catholyte enables a new generation of transformative high performance, low temperature molten sodium batteries.

Abstract: The present invention is directed to the modification of sodium electrochemical interfaces to improve performance of sodium ion-conducting ceramics in a variety of electrochemical applications. Enhanced mating of the separator-sodium interface by means of engineered coatings or other surface modifications results in lower interfacial resistance and higher performance at increased current densities, enabling the effective operation of molten sodium batteries and other electrochemical technologies at low and high temperatures.

Abstract: The invention is directed to a chemically robust, highly-selective, low power sensor that can be used for the direct electrical detection of mixed gases. In particular, metal-organic frameworks (MOFs) offer exceptional chemical and structural tunability as mixed-gas capture materials. As an example of the invention, the influence of interfering gases on trace NO2 detection in a simulated flue gas stream was investigated. The unique interaction of NO2 with the MOF's metal center leads to orders of magnitude decrease in MOF resistance. More broadly, the coadsorption of specific gases (e.g., H2O, SO2) can be beneficial to the electrical detection of the target gas (e.g., NO2), and careful electrical measurements can discern their presence independent of the target gas.

Abstract: A sodium-ion conducting NaSICON ceramic can be densified via the addition of a solvent to a NaSICON powder and subsequent pressing under high pressure and mild heat. Densification to ˜90% relative density can be achieved, providing a path toward low-temperature fabrication of Na-ion conductors.

Abstract: Detection and capture of toxic nitrogen oxides (NOx) is important for emissions control of exhaust gases and general public health. The low power sensor provides direct electrically detection of trace (0.5-5 ppm) NO2 at relatively low temperatures (50° C.) via changes in the electrical properties of nitrogen-oxide-capture active materials. For example, the high impedance of MOF-74 enables applications requiring a near-zero power sensor or dosimeter, such as for smart industrial systems and the internet of things, with 0.8 mg MOF-74 active material drawing <15 pW for a macroscale sensor 35 mm2 area.

Abstract: The invention is directed to a mediated metal-sulfur flow battery. This battery format that is readily scalable to grid-scale levels at low cost, while maintaining battery safety by physically separating the anode and cathode. As an example, the marriage of a redox-targeting scheme to an engineered Li solid electrolyte interphase (SEI) enables a scalable, high efficiency, membrane-less Li—S redox flow battery. Redox mediators can be sued to kick-start the initial reduction of solid S into soluble polysulfides on the cathode side and final reduction of polysulfides into solid Li2S, precluding the need for conductive carbons. On the anode side, a LiI and LiNO3 pretreatment and additive strategy encourages a stable SEI and lessens capacity fade, avoiding the need for ion-selective separators.

Abstract: The present invention is directed to the modification of sodium electrochemical interfaces to improve performance of NaSICON-type ceramics in a variety of electrochemical applications. Enhanced mating of the separator-sodium interface by means of engineered coatings or other surface modifications results in lower interfacial resistance and higher performance at increased current densities, enabling the effective operation of molten sodium batteries and other electrochemical technologies at low and high temperatures.

Abstract: Detection and capture of toxic nitrogen oxides (NOx) is important for emissions control of exhaust gases and general public health. The low power sensor provides direct electrically detection of trace (0.5-5 ppm) NO2 at relatively low temperatures (50° C.) via changes in the electrical properties of nitrogen-oxide-capture active materials. For example, the high impedance of MOF-74 enables applications requiring a near-zero power sensor or dosimeter, such as for smart industrial systems and the internet of things, with 0.8 mg MOF-74 active material drawing <15 pW for a macroscale sensor 35 mm2 area.

Abstract: A molten sodium-based battery comprises a robust, highly Na-ion conductive, zero-crossover separator and a fully inorganic, fully liquid, highly cyclable molten cathode that operates at low temperatures.

Abstract: A sodium-ion conducting NaSICON ceramic can be densified via the addition of a solvent to a NaSICON powder and subsequent pressing under high pressure and mild heat. Densification to ˜90% relative density can be achieved, providing a path toward low-temperature fabrication of Na-ion conductors.

Abstract: The present invention is directed to the modification of sodium electrochemical interfaces to improve performance of NaSICON-type ceramics in a variety of electrochemical applications. Enhanced mating of the separator-sodium interface by means of engineered coatings or other surface modifications results in lower interfacial resistance and higher performance at increased current densities, enabling the effective operation of molten sodium batteries and other electrochemical technologies at low and high temperatures.

Abstract: A molten sodium-based battery comprises a robust, highly Na-ion conductive, zero-crossover separator and a fully inorganic, fully liquid, highly cyclable molten cathode that operates at low temperatures.

Abstract: Nanostructured polyelectrolyte bilayers deposited by Layer-by-Layer deposition on nanoporous membranes can be selectively crosslinked to modify the polyelectrolyte charge density and control ionic selectivity independent of ionic conductivity. For example, the polyelectrolyte bilayer can comprise a cationic polymer layer, such as poly(ethyleneimine), and an anionic polymer layer, such as poly(acrylic acid). Increasing the number of bilayers increases the cation selectivity when the poly(ethyleneimine) layer is crosslinked with glutaraldehyde. Crosslinking the membranes also increases the chemical and mechanical strength of the polyelectrolyte films. This controllable and inexpensive method can be used to create ion-selective and mechanically robust membranes on porous supports for a wide range of applications.

Abstract: An alternating current electrodialysis device that uses two synergistic energy efficiency-increasing improvements to a traditional electrodialysis system: (1) membranes which rectify ionic currents and (2) supercapacitor electrodes. Together these components enable alternating current electrodialysis, offering significantly decreased system complexity, improved energy efficiency, and increased systems lifetimes.

Abstract: Nanostructured polyelectrolyte bilayers deposited by Layer-by-Layer deposition on nanoporous membranes can be selectively crosslinked to modify the polyelectrolyte charge density and control ionic selectivity independent of ionic conductivity. For example, the polyelectrolyte bilayer can comprise a cationic polymer layer, such as poly(ethyleneimine), and an anionic polymer layer, such as poly(acrylic acid). Increasing the number of bilayers increases the cation selectivity when the poly(ethyleneimine) layer is crosslinked with glutaraldehyde. Crosslinking the membranes also increases the chemical and mechanical strength of the polyelectrolyte films. This controllable and inexpensive method can be used to create ion-selective and mechanically robust membranes on porous supports for a wide range of applications.

Abstract: Nonaqueous redox flow batteries (RFB) hold the potential for high energy density grid scale storage, though are often limited by the solubility of the redox-active species in their electrolytes. A systematic approach enables an increase the concentration of redox-active species in electrolytes for nonaqueous RFB, starting from a metal-coordination-cation-based ionic liquid. As an example, starting with an ionic liquid consisting of a metal coordination cation (MetIL), ferrocene-containing ligands and iodide anions can be substituted into the original MetIL structure, enabling a nearly 4× increase in capacity compared to original MetIL structure. Application of this strategy to other chemistries, optimizing electrolyte melting point and conductivity could yield >10 M redox-active electrons.

Abstract: An all solid-state, MOF-, zeolite-, or activated carbon-based electrical readout sensor with a long-lived signal can be tuned specifically for real-time sensing of iodine gas in ambient conditions. The sensor may be of use in nuclear accident scenarios for first responders and/or as process sensors in advanced nuclear fuel recycling.

Abstract: Nonaqueous redox flow batteries (RFB) hold the potential for high energy density grid scale storage, though are often limited by the solubility of the redox-active species in their electrolytes. A systematic approach enables an increase the concentration of redox-active species in electrolytes for nonaqueous RFB, starting from a metal-coordination-cation-based ionic liquid. As an example, starting with an ionic liquid consisting of a metal coordination cation (MetIL), ferrocene-containing ligands and iodide anions can be substituted into the original MetIL structure, enabling a nearly 4× increase in capacity compared to original MetIL structure. Application of this strategy to other chemistries, optimizing electrolyte melting point and conductivity could yield >10 M redox-active electrons.

Abstract: The invention provides an inexpensive, scalable process for coating materials with a film of a refractory metal. As an example, the immersion process can comprise the deposition of a sacrificial zinc coating which is galvanically displaced by the ether-mediated reduction of oxophilic WCl6 to form a complex WOxCly film, and subsequently annealed to crystalline, metallic tungsten. The efficacy of this process was demonstrated on a carbon foam electrode, showing a 50% decrease in electrode resistance and significant gains in electrochemical performance. This process enables voltage efficiency gains for electrodes in batteries, redox flow batteries, and industrial processes where high conductivity and chemical stability are paramount.

Abstract: Nonaqueous redox flow batteries (RFB) hold the potential for high energy density grid scale storage, though are often limited by the solubility of the redox-active species in their electrolytes. A systematic approach enables an increase the concentration of redox-active species in electrolytes for nonaqueous RFB, starting from a metal-coordination-cation-based ionic liquid. As an example, starting with an ionic liquid consisting of a metal coordination cation (MetIL), ferrocene-containing ligands and iodide anions can be substituted into the original MetIL structure, enabling a nearly 4× increase in capacity compared to original MetIL structure. Application of this strategy to other chemistries, optimizing electrolyte melting point and conductivity could yield >10 M redox-active electrons.