MIL-53 Metal–Organic Framework as a Flexible Cathode for Lithium-Oxygen Batteries

Li-air batteries possess higher specific energies than the current Li-ion batteries. Major drawbacks of the air cathode include the sluggish kinetics of the oxygen reduction (OER), high overpotentials and pore clogging during discharge processes. Metal–Organic Frameworks (MOFs) appear as promising materials because of their high surface areas, tailorable pore sizes and catalytic centers. In this work, we propose to use, for the first time, aluminum terephthalate (well known as MIL-53) as a flexible air cathode for Li-O2 batteries. This compound was synthetized through hydrothermal and microwave-assisted routes, leading to different particle sizes with different aspect ratios. The electrochemical properties of both materials seem to be equivalent. Several behaviors are observed depending on the initial value of the first discharge capacity. When the first discharge capacity is higher, no OER occurs, leading to a fast decrease in the capacity during cycling. The nature and the morphology of the discharge products are investigated using ex situ analysis (XRD, SEM and XPS). For both MIL-53 materials, lithium peroxide Li2O2 is found as the main discharge product. A morphological evolution of the Li2O2 particles occurs upon cycling (stacked thin plates, toroids or pseudo-spheres).

Simulation of bi-layer cathode materials with experimentally validated parameters to improve ion diffusion and discharge capacity

Simulation shows that higher electrode utilization (next to current collector) and first discharge capacity can be achieved at high C-rates with bi-layer design compare to conventional electrodes, alongside an increase in energy-power density.

A Rechargeable Na/Cl Battery

Sodium is a promising anode material for batteries due to its low standard electrode potential, high abundance and low cost. In this work, we report a new rechargeable ~ 3.5 V sodium ion battery using Na anode, amorphous carbon-nanosphere cathode and a starting electrolyte comprised of AlCl3 in SOCl2 with fluoride-based additives. The battery, exhibiting ultrahigh ~ 2800 mAh/g first discharge capacity, could cycle with a high reversible capacity up to ~ 1000 mAh/g. Through battery cycling, the electrolyte evolved to contain NaCl, various sulfur and chlorine species that supported anode’s Na/Na+ redox and cathode’s chloride/chlorine redox. Fluoride-rich additives were important in forming a solid-electrolyte interface, affording reversibility of the Na anode for a new class of high capacity secondary Na battery.

Template-Free Electrochemical Preparation of Hexagonal CuSn Prism-Structural Electrode for Lithium-Ion Batteries

A hexagonal prism CuSn alloy was prepared at room temperature from 1-ethyl-3-methylimidazolium dicyanamide ([Emim][DCA]) by the direct template-free electrodeposition method with different concentrations of Cu(I) and Sn(II) at a low current density of 0.04 A dm−2. Moreover, the electrodeposition time was also investigated, and the results indicated that the composition of the CuSn alloy became complex and the structure turned unstable with expanding time. The cycling performance of the hexagonal prism-structural CuSn electrode was investigated, with the first discharge capacity of 345 mAh g−1 and a discharge capacity of about 210 mAh g−1 after 10 cycles.

Synthesis and electrochemical performance of NaV6O15 microflowers for lithium and sodium ion batteries

High first discharge capacity of 255 mA h g−1 (vs. Li+/Li) and 130 mA h g−1 (vs. Na+/Na) were observed in NaV6O15 microflowers and the capacity retention reaches 105% and 64% after 50 cycles at the current density of 100 mA g−1 and 50 mA g−1, respectively.

Na-X zeolite templated and sulfur-impregnated porous carbon as the cathode for a high-performance Li–S battery

A-ZPC-S composite is an excellent and promising cathode for high-performance Li-S batteries. With 46 wt% sulfur loading, it exhibited a first discharge capacity of 1204 mA h g−1and a reversible capacity of 691 mA h g−1after 300 cycles, fading only 0.142% per cycle.

Synthesis and electrochemical properties of Li(Fe0.5Co0.5)BO3

A new borate compound LiFe0.5Co0.5BO3 has been successfully synthesized for the first time by a multiple-step process. This compound delivers a very interesting first discharge capacity of 120 mA h g−1 at C/20 rate without in situ carbon coating.

Electrochemical Title Performance of LiMn2O4 Synthesized by Flameless Solution Combustion with Acetate System

LiMn2O4was synthesized by flameless solution combustion at 600°C for 3 hours (h). The influence of HNO3on the morphologies, crystal structure and electrochemical performances of the material was investigated. The results show that the main phase of all synthesized products is LiMn2O4, and the impurities are Mn2O3or Mn3O4depending on the concentration of HNO3(CHNO3). While CHNO3=0 and 15 mol L-1, the impurity was Mn2O3, when the concentrations of HNO3from 3 to 9 mol L-1, the impurity was Mn3O4; at CHNO3=12 mol L-1, the synthesized product was single phase; CHNO3≤12 mol L-1, with the increase of CHNO3, particles size grew from 70-130 nm to 140-500 nm, however, CHNO3is up to 15 mol L-1, particles become small (70-140 nm); the single phase of LiMn2O4obtained the maximum first discharge capacity (119.7 mAh g-1) at CHNO3=12 mol L-1, but its retention rate was undesirable, while CHNO3=15 mol L-1, the cycling performance of the product was the optimum with first discharge capacity of 118.5 mAh g-1and capacity retention of 90.9 % after 40 cycles at 0.2 C.

A low dimensional composite of hexagonal lithium manganese borate (LiMnBO3), a cathode material for Li-ion batteries

The nano h-LiMnBO3 composite delivers a high first discharge capacity of 140 mA h g−1 at C/15 rate within a reduced potential window.

A Study about the Synthesis Characterization and Electrochemical Properties of γ-MnOOH Nanowires

In this paper, manganite (γ-MnOOH) nanowires have been synthesized, using KMnO4 and CTAB as raw materials, by a hydrothermal method at 180°C for 12h. The samples were characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscope (SEM),and thermogravimetric analysis (TG) for the information of crystal form, size, d-spacings, morphology and the weight-loss course. The results showed the manganite nanowires diameter range from 15 nm to 150 nm,length range from 5μm to 20 μm. Moreover, the properties of manganite (γ-MnOOH) nanowires as anode materials for Li-ion batteries had been studied. The first-discharge capacity is 1660 mAh g-1 and corresponds to a consumption of about 5.5 moles of Li per mole of MnOOH, which made this material maybe one of the candidates for the negative materials.