Human Hemoglobin-Based Zinc-Air Battery in a Neutral Electrolyte.

The use of human hemoglobin (Hb) as a catalytic component of the air electrode in a primary zinc-air battery with a neutral electrolyte has been investigated. Three different electrode modifications, using the drop-casting method, with Hb and Nafion were first tested in a three-electrode cell, obtaining the best oxygen electroreduction (ORR) performance and long-term stability with a Hb plus Nafion (Hb-Nafion)-modified electrode. The latter Hb-Nafion-based air electrode provided a higher specific capacity and discharge time than the opposite order (Nafion-Hb).

Bifunctional P-Containing RuO Catalysts Prepared from Surplus Ru Co-Ordination Complexes and Applied to Zn/Air Batteries.

An innovative synthetic route that involves the thermal treatment of selected Ru co-ordination complexes was used to prepare RuO-based materials with catalytic activity for oxygen reduction (ORR) and oxygen evolution (OER) reactions. Extensive characterization confirmed the presence of Ru metal and RuPO in the materials, with an improved electrocatalytic performance obtained from calcinated [(RuCl(PPh)]. A mechanistic approach for the obtention of such singular blends and for the synergetic contribution of these three species to electrocatalysis is suggested.

Properties of the PVA-VAVTD KOH Blend as a Gel Polymer Electrolyte for Zinc Batteries.

Rechargeable zinc-air batteries are promising for energy storage and portable electronic applications because of their good safety, high energy density, material abundance, low cost, and environmental friendliness. A series of alkaline gel polymer electrolytes formed from polyvinyl alcohol (PVA) and different amounts of terpolymer composed of butyl acrylate, vinyl acetate, and vinyl neodecanoate (VAVTD) was synthesized applying a solution casting technique. The thin films were doped with KOH 12M, providing a higher amount of water and free ions inside the electrolyte matrix.

A Review of the Use of GPEs in Zinc-Based Batteries. A Step Closer to Wearable Electronic Gadgets and Smart Textiles.

With the flourish of flexible and wearable electronics gadgets, the need for flexible power sources has become essential. The growth of this increasingly diverse range of devices boosted the necessity to develop materials for such flexible power sources such as secondary batteries, fuel cells, supercapacitors, sensors, dye-sensitized solar cells, etc. In that context, comprehensives studies on flexible conversion and energy storage devices have been released for other technologies such Li-ion standing out the importance of the research done lately in GPEs (gel polymer electrolytes) for energy conversion and storage.

Influence of the Ionic Liquid Type on the Gel Polymer Electrolytes Properties.

Gel Polymer Electrolytes (GPEs) composed by ZnTf₂ salt, poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), and different ionic liquids are synthesized using n-methyl-2-pyrrolidone (NMP) as solvent. Three different imidazolium-based ionic liquids containing diverse cations and anions have been explored. Structural and electrical properties of the GPEs varying the ZnTf₂ concentration are analyzed by ATR-FTIR, DSC, TG, and cyclic voltammetry.

A new method based on the Butler-Volmer formalism to evaluate voltammetric cation and anion sensors.

A new method based on the Butler-Volmer formalism is applied to assess the capability of two voltammetric ion sensors based on polypyrrole films: PPy/DBS and PPy/ClO4 modified electrodes were studied as voltammetric cation and anion sensors, respectively. The reversible potential versus electrolyte concentrations semilogarithm plots provided positive calibration slopes for PPy/DBS and negative ones for PPy/ClO4, as was expected from the proposed method and that based on the Nernst equation. The slope expressions deduced from Butler-Volmer include the electron-transfer coefficient, which allows slope values different from the ideal Nernstian value to be explained.

In situ FTIR spectroscopy study of the break-in phenomenon observed for PPy/PVS films in acetonitrile.

The in situ Fourier transform infrared (in situ FTIR) technique was used for the first time to investigate the break-in phenomenon observed for polypyrrole/poly(vinyl sulfonate) (PPy/PVS) films in acetonitrile containing 0.1 M LiClO(4). Consecutive potential scans provided a continuous increase of the infrared band intensities, simultaneous to an increase observed in the charge involved in the voltammetric peaks, suggesting a rise in the number of the polymeric chains participating in the infrared signal at the same time as the electroactive participants increase in the redox process.