Reaction kinetics of lithium-sulfur batteries with a polar Li-ion electrolyte: modeling of liquid phase and solid phase processes.

The present investigation fits the reaction kinetics of a lithium-sulfur (Li-S) battery with polar electrolyte employing a novel two-phase continuum multipore model. The continuum two-phase model considers processes in both the liquid electrolyte phase and the solid precipitates phase, where the diffusion coefficients of the Li ions in a solvent-softened solid state are determined from molecular dynamics simulations. Solubility experiments yield the saturation concentration of sulfur and lithium sulfides in the polar electrolyte employed in this study.

Designing a Graphene Coating-Based Supercapacitor with Lithium Ion Electrolyte: An Experimental and Computational Study via Multiscale Modeling.

Graphene electrodes are investigated for electrochemical double layer capacitors (EDLCs) with lithium ion electrolyte, the focus being the effect of the pore size distribution (PSD) of electrode with respect to the solvated and desolvated electrolyte ions. Two graphene electrode coatings are examined: a low specific surface area (SSA) xGNP-750 coating and a high SSA coating based on a-MWGO (activated microwave expanded graphene oxide). The study comprises an experimental and a computer modeling part.

Facile synthesis of pyrite (FeS/C) nanoparticles as an electrode material for non-aqueous hybrid electrochemical capacitors.

Pyrite (FeS2) is a promising electrode material for lithium ion batteries (LIBs) because of its high natural availability, low toxicity, cost-effectiveness, high theoretical capacity (894 mA h g-1) and high theoretical specific energy density (1270 W h kg-1, 4e-/FeS2). Nevertheless, the use of FeS2 in electrochemical capacitors was restricted due to fast capacity fading as a result of polysulfide (S/Sn2-) formation during the initial electrochemical cycling. In order to avoid the formation of polysulfides, we employed the strategy of utilizing an ether based electrolyte (1.

An Enhanced High-Rate NaV(PO)-NiP Nanocomposite Cathode with Stable Lifetime for Sodium-Ion Batteries.

Herein, we report on a high-discharge-rate NaV(PO)-NiP/C (NVP-NP/C) composite cathode prepared using a polyol-based pyro synthesis for Na-ion battery applications. X-ray diffraction and electron microscopy studies established the presence of NaV(PO) and NiP, respectively, in the NVP-NP/C composite. As a cathode material, the obtained NVP-NP/C composite electrode exhibits higher discharge capacities (100.

One-Step Pyro-Synthesis of a Nanostructured Mn O /C Electrode with Long Cycle Stability for Rechargeable Lithium-Ion Batteries.

A nanostructured Mn O /C electrode was prepared by a one-step polyol-assisted pyro-synthesis without any post-heat treatments. The as-prepared Mn O /C revealed nanostructured morphology comprised of secondary aggregates formed from carbon-coated primary particles of average diameters ranging between 20 and 40 nm, as evidenced from the electron microscopy studies. The N adsorption studies reveal a hierarchical porous feature in the nanostructured electrode.

Rapid Polyol-Assisted Microwave Synthesis of Nanocrystalline LiFePO4/C Cathode for Lithium-Ion Batteries.

Nanocrystalline LiFePO4/C has been synthesized under a very short period of time (90 sec) using a polyol-assisted microwave heating synthesis technique. The X-ray diffraction (XRD) data indicates that the rapidly synthesized materials correspond to phase pure olivine. Post-annealing of the as-prepared sample at 600 °C in argon atmosphere yields highly crystalline LiFePO4/C.

Hierarchical porous anatase TiO2 derived from a titanium metal-organic framework as a superior anode material for lithium ion batteries.

Hierarchical meso-/macroporous anatase TiO2 was synthesized by the hydrolysis of a titanium metal-organic framework precursor followed by calcination in air. This unique porous feature enables the superior rate capability and excellent cycling stability of anatase TiO2 as an anode for rechargeable lithium-ion batteries.

Low-temperature synthesis of LiFePO4 nanocrystals by solvothermal route.

LiFePO4 nanocrystals were synthesized at a very low temperature of 170°C using carbon nanoparticles by a solvothermal process in a polyol medium, namely diethylene glycol without any heat treatment as a post procedure. The powder X-ray diffraction pattern of the LiFePO4 was indexed well to a pure orthorhombic system of olivine structure (space group: Pnma) with no undesirable impurities. The LiFePO4 nanocrystals synthesized at low temperature exhibited mono-dispersed and carbon-mixed plate-type LiFePO4 nanoparticles with average length, width, and thickness of approximately 100 to 300 nm, 100 to 200 nm, and 50 nm, respectively.