Does Cell Polarization Matter in Single-Ion Conducting Electrolytes?

Single-ion conducting polymer electrolytes (SIPE) are particularly promising electrolyte materials in lithium metal-based batteries since theoretical considerations suggest that the immobilization of anions avoids polarization phenomena at electrode|electrolyte interfaces. SIPE in principle could allow for fast charging while preventing cell failure induced by short circuits arising from the growth of inhomogeneous Li depositions provided that SIPE membranes possess sufficient mechanical stability. To date, different chemical structures are developed for SIPE, where new compounds are often reported through electrochemical characterization at low current rates.

An In Situ Cross-Linked Nonaqueous Polymer Electrolyte for Zinc-Metal Polymer Batteries and Hybrid Supercapacitors.

This work reports the facile synthesis of nonaqueous zinc-ion conducting polymer electrolyte (ZIP) membranes using an ultraviolet (UV)-light-induced photopolymerization technique, with room temperature (RT) ionic conductivity values in the order of 10 S cm . The ZIP membranes demonstrate excellent physicochemical and electrochemical properties, including an electrochemical stability window of >2.4 V versus Zn|Zn and dendrite-free plating/stripping processes in symmetric Zn||Zn cells.

Dioxolanone-Anchored Poly(allyl ether)-Based Cross-Linked Dual-Salt Polymer Electrolytes for High-Voltage Lithium Metal Batteries.

Novel cross-linked polymer electrolytes (XPEs) are synthesized by free-radical copolymerization induced by ultraviolet (UV)-light irradiation of a reactive solution, which is composed of a difunctional poly(ethylene glycol) diallyl ether oligomer (PEGDAE), a monofunctional reactive diluent 4-vinyl-1,3-dioxolan-2-one (VEC), and a stock solution containing lithium salt (lithium bis(trifluoromethanesulfonyl)imide, LiTFSI) in a carbonate-free nonvolatile plasticizer, poly(ethylene glycol) dimethyl ether (PEGDME). The resulting polymer matrix can be represented as a linear polyethylene chain functionalized with cyclic carbonate (dioxolanone) moieties and cross-linked by ethylene oxide units. A series of XPEs are prepared by varying the [O]/[Li] ratio (24 to 3) of the stock solution and thoroughly characterized using physicochemical (thermogravimetric analysis-mass spectrometry, differential scanning calorimetry, NMR, etc.

Understanding the Effect of UV-Induced Cross-Linking on the Physicochemical Properties of Highly Performing PEO/LiTFSI-Based Polymer Electrolytes.

We report a thorough, multitechnique investigation of the structure and transport properties of a UV-cross-linked polymer electrolyte based on poly(ethylene oxide), tetra(ethylene glycol)dimethyl ether (G4), and lithium bis(trifluoromethane)sulfonimide. The properties of the cross-linked polymer electrolyte are compared to those of a non-cross-linked sample of same composition. The effect of UV-induced cross-linking on the physico/chemical characteristics is evaluated by X-ray diffraction, differential scanning calorimetry, shear rheology, H and Li magic angle spinning nuclear magnetic resonance (NMR) spectroscopy, F and Li pulsed field gradient stimulated echo NMR analyses, electrochemical impedance spectroscopy, and Fourier transform Raman spectroscopy.

Scaling Atomic Partial Charges of Carbonate Solvents for Lithium Ion Solvation and Diffusion.

Lithium-ion solvation and diffusion properties in ethylene carbonate (EC) and propylene carbonate (PC) were studied by molecular simulation, experiments, and electronic structure calculations. Studies carried out in water provide a reference for interpretation. Classical molecular dynamics simulation results are compared to ab initio molecular dynamics to assess nonpolarizable force field parameters for solvation structure of the carbonate solvents.

Single-Ion Block Copoly(ionic liquid)s as Electrolytes for All-Solid State Lithium Batteries.

Polymer electrolytes have been proposed as replacement for conventional liquid electrolytes in lithium-ion batteries (LIBs) due to their intrinsic enhanced safety. Nevertheless, the power delivery of these materials is limited by the concentration gradient of the lithium salt. Single-ion conducting polyelectrolytes represent the ideal solution since their nature prevents polarization phenomena.

Super Soft All-Ethylene Oxide Polymer Electrolyte for Safe All-Solid Lithium Batteries.

Here we demonstrate that by regulating the mobility of classic -EO- based backbones, an innovative polymer electrolyte system can be architectured. This polymer electrolyte allows the construction of all solid lithium-based polymer cells having outstanding cycling behaviour in terms of rate capability and stability over a wide range of operating temperatures. Polymer electrolytes are obtained by UV-induced (co)polymerization, which promotes an effective interlinking between the polyethylene oxide (PEO) chains plasticized by tetraglyme at various lithium salt concentrations.

Photopolymer Electrolytes for Sustainable, Upscalable, Safe, and Ambient-Temperature Sodium-Ion Secondary Batteries.

The first example of a photopolymerized electrolyte for a sodium-ion battery is proposed herein. By means of a preparation process free of solvents, catalysts, purification steps, and separation steps, it is possible to obtain a three-dimensional polymeric network capable of efficient sodium-ion transport. The thermal properties of the resulting solid electrolyte separator, characterized by means of thermogravimetric and calorimetric techniques, are excellent for use in sustainable energy systems conceived for safe large-scale grid storage.

Newly Elaborated Multipurpose Polymer Electrolyte Encompassing RTILs for Smart Energy-Efficient Devices.

Profoundly ion-conducting, self-standing, and tack-free ethylene oxide-based polymer electrolytes encompassing a room-temperature ionic liquid (RTIL) with specific amounts of lithium salt are successfully prepared via a rapid and easily upscalable process including a UV irradiation step. All prepared materials are thoroughly characterized in terms of their physical, chemical, and morphological properties and eventually galvanostatically cycled in lab-scale lithium batteries (LIBs) exploiting a novel direct polymerization procedure to get intimate electrode/electrolyte interfacial characteristics. The promising multipurpose characteristics of the newly elaborated materials are demonstrated by testing them in dye-sensitized solar cells (DSSCs), where the introduction of the iodine/iodide-based redox mediator in the polymer matrix assured the functioning of a lab-scale test cell with conversion efficiency exceeding 6% at 1 sun.

Temperature dependence of electric transport in few-layer graphene under large charge doping induced by electrochemical gating.

The temperature dependence of electric transport properties of single-layer and few-layer graphene at large charge doping is of great interest both for the study of the scattering processes dominating the conductivity at different temperatures and in view of the theoretically predicted possibility to reach the superconducting state in such extreme conditions. Here we present the results obtained in 3-, 4- and 5-layer graphene devices down to 3.5 K, where a large surface charge density up to about 6.

A UV-crosslinked polymer electrolyte membrane for quasi-solid dye-sensitized solar cells with excellent efficiency and durability.

Here we report on a novel polymer electrolyte membrane for quasi-solid dye-sensitized solar cells (DSSCs) with excellent efficiency and extended durability. The electrolyte is prepared by an elegant, rapid and cheap UV-induced polymerization method and the chemometric approach is used for the first time, to the best of our knowledge, for the optimization and the fine tuning of the experimental conditions.

Large conductance modulation of gold thin films by huge charge injection via electrochemical gating.

By using an electrochemical gating technique with a new combination of polymer and electrolyte, we were able to inject surface charge densities n(2D) as high as 3.5×10(15)  e/cm(2) in gold films and to observe large relative variations in the film resistance, ΔR/R', up to 10% at low temperature. ΔR/R' is a linear function of n(2D)-as expected within a free-electron model-if the film is thick enough (≥25  nm); otherwise, a tendency to saturation due to size effects is observed.

UV-Induced Radical Photo-Polymerization: A Smart Tool for Preparing Polymer Electrolyte Membranes for Energy Storage Devices.

In the present work, the preparation and characterization of quasi-solid polymer electrolyte membranes based on methacrylic monomers and oligomers, with the addition of organic plasticizers and lithium salt, are described. Noticeable improvements in the mechanical properties by reinforcement with natural cellulose hand-sheets or nanoscale microfibrillated cellulose fibers are also demonstrated. The ionic conductivity of the various prepared membranes is very high, with average values approaching 10-3 S cm-1 at ambient temperature.

UV-Induced Radical Photo-Polymerization: A Smart Tool for Preparing Polymer Electrolyte Membranes for Energy Storage Devices.

In the present work, the preparation and characterization of quasi-solid polymer electrolyte membranes based on methacrylic monomers and oligomers, with the addition of organic plasticizers and lithium salt, are described. Noticeable improvements in the mechanical properties by reinforcement with natural cellulose hand-sheets or nanoscale microfibrillated cellulose fibers are also demonstrated. The ionic conductivity of the various prepared membranes is very high, with average values approaching 10-3 S cm-1 at ambient temperature.

Metallopolymer capacitor in "one pot" by self-directed UV-assisted process.

Silver metalized methacrylate films are prepared by single-step UV curing process with good conductivity on both sides. The major component of the composite is Bisphenol A ethoxylate dimethacrylate, which can be photopolymerized by a photoreactive initiator under UV light. Under the same conditions of UV irradiation, silver ions are deposited as metal nanoparticles while the pyrrole is oxidized to polypyrrole.