Recycling Compatible Organic Electrode Materials Containing Amide Bonds for Use in Rechargeable Batteries.

Organic rechargeable batteries that do not use any scarce heavy metals are candidates for the next generation of rechargeable batteries; although, it is not easy to realize both high capacity and long cycle life. Organic compounds linked by amide bonds are expected to have superior recycling properties after battery degradation, since they will become a single monomer upon hydrolysis. In this study, anthraquinone was chosen as a model redox active unit, and dimeric and trimeric compounds were synthesized, their cycle performances as electrode materials for use in rechargeable batteries were compared, and a trend in which oligomerization improves cycle properties was confirmed.

Improvement in Cycle Life of Organic Lithium-Ion Batteries by In-Cell Polymerization of Tetrathiafulvalene-Based Electrode Materials.

Redox-active organic molecules are promising candidates for next-generation electrode materials. Nevertheless, finding low-molecular-weight organic materials with a long cycle life remains a crucial challenge. Herein, we demonstrate the application of tetrathiafulvalene and its vinyl analogue bearing triphenylamines as long-cycle-life electrodes for lithium-ion batteries (LIBs).

Improvement of the Battery Performance of Indigo, an Organic Electrode Material, Using PEDOT/PSS with d-Sorbitol.

Rare-metal-free and high-performance secondary batteries are necessary for improving the efficiency of renewable energy systems. Organic compounds are attractive candidates for the active material of such batteries. Many studies have reported organic active materials that show high energy density per active material weight.

Analytical Measurements to Elucidate Structural Behavior of 2,5-Dimethoxy-1,4-benzoquinone During Charge and Discharge.

Organic compounds as electrode materials can contribute to sustainability because they are nontoxic and environmentally abundant. The working mechanism during charge-discharge for reported organic compounds as electrode materials is yet to be completely understood. In this study, the structural behavior of 2,5-dimethoxy-1,4-benzoquinone (DMBQ) during charge-discharge is investigated by using NMR spectroscopy, energy-dispersive X-ray spectroscopy, magnetic measurements, operando Raman spectroscopy, and operando X-ray diffraction.

Fused Tetrathiafulvalene and Benzoquinone Triads: Organic Positive-Electrode Materials Based on a Dual Redox System.

Fused donor-acceptor triads composed of two tetrathiafulvalenes (TTFs) and benzoquinone (BQ; 1) or naphthoquinone (NQ; 2) were successfully synthesized. X-ray structure analysis of the bis(n-butylthio) derivative revealed that the molecules are stacked in a head-to-tail manner. The bis(n-hexylthio)-1 exhibited six-pairs of one-electron transfer waves in the cyclic voltammogram, corresponding to the formation of both reduction and oxidation states from -2 to +4.

Viologen Derivatives Extended with Aromatic Rings Acting as Negative Electrode Materials for Use in Rechargeable Molecular Ion Batteries.

Many types of batteries have been proposed as next-generation energy-storage systems. One candidate is a rocking-chair-type "molecular ion battery" in which a molecular ion, instead of Li , works as a charge carrier. Previously, we reported a viologen-type derivative as a negative electrode material that releases and receives PF anions during the charge-discharge process; however, its redox potential was not satisfactorily low.

Anthraquinone-Based Oligomer as a Long Cycle-Life Organic Electrode Material for Use in Rechargeable Batteries.

An anthraquinone (AQ)-based dimer and trimer linked by a triple bond (-C≡C-) were newly synthesized as active materials for the positive electrode of rechargeable lithium batteries. These synthesized oligomers exhibited an initial discharge capacity of about 200 mAh g with an average voltage of 2.2-2.

Characterization of a Rh(III) porphyrin-CO complex: its structure and reactivity with an electron acceptor.

To analyse the electrocatalytic oxidation of carbon monoxide by Rh porphyrins, we isolated a CO-adduct of Rh octaethylporphyrin, and examined its properties and reactivity by IR, NMR, and X-ray crystallographic analyses. The results indicate that the CO adduct of Rh octaethylporphyrin is vulnerable to nucleophilic attack by H2O. The CO-adduct was easily oxidized by an electron acceptor (1,4-naphthoquinone) to generate CO2.

Molecular ion battery: a rechargeable system without using any elemental ions as a charge carrier.

Is it possible to exceed the lithium redox potential in electrochemical systems? It seems impossible to exceed the lithium potential because the redox potential of the elemental lithium is the lowest among all the elements, which contributes to the high voltage characteristics of the widely used lithium ion battery. However, it should be possible when we use a molecule-based ion which is not reduced even at the lithium potential in principle. Here we propose a new model system using a molecular electrolyte salt with polymer-based active materials in order to verify whether a molecular ion species serves as a charge carrier.

Indigo carmine: an organic crystal as a positive-electrode material for rechargeable sodium batteries.

Using sodium, instead of lithium, in rechargeable batteries is a way to circumvent the lithium's resource problem. The challenge is to find an electrode material that can reversibly undergo redox reactions in a sodium-electrolyte at the desired electrochemical potential. We proved that indigo carmine (IC, 5,5'-indigodisulfonic acid sodium salt) can work as a positive-electrode material in not only a lithium-, but also a sodium-electrolyte.

Electrocatalytic oxidation of alcohols by a carbon-supported Rh porphyrin.

A Rh porphyrin on carbon black was shown to catalyze the electro-oxidation of several aliphatic alcohols (ethanol, 1-propanol, and 2-propanol) and benzyl alcohols. The overpotentials for alcohol oxidation were very low. The reaction mechanism and substrate specificity are discussed.

Amphiphilic meso-disubstituted porphyrins: synthesis and the effect of the hydrophilic group on absorption spectra at the air-water interface.

Five amphiphilic meso-disubstituted porphyrins bearing one polar group were synthesized, and their monolayer films were prepared. Their limiting molecular areas obtained from pi-A isotherms were 0.5-0.