Flow batteries, in which the electro-active components are held in fluid form external to the battery itself, are attractive as a potential means for regulating the output of intermittent renewable sources of electricity; an aqueous flow battery based on inexpensive commodity chemicals is now reported that also has the virtue of enabling further improvement of battery performance through organic chemical design. Flow batteries differ from the conventional type in that the electro-active components of flow batteries are held in fluid form external to the battery itself, enabling such systems to store arbitrarily large amounts of energy. Flow batteries are therefore attractive as a potential means for regulating the output of intermittent sources of electricity such as wind or solar power. But an important limitation of most such systems is the abundance and cost of the electro-active materials. To overcome this limitation, Brian Huskinson and colleagues have developed an aqueous flow battery on the basis of inexpensive, non-metallic commodity chemicals, with the added advantage of enabling the tuning of key battery properties through chemical design. As the fraction of electricity generation from intermittent renewable sources—such as solar or wind—grows, the ability to store large amounts of electrical energy is of increasing importance. Solid-electrode batteries maintain discharge at peak power for far too short a time to fully regulate wind or solar power output1,2. In contrast, flow batteries can independently scale the power (electrode area) and energy (arbitrarily large storage volume) components of the system by maintaining all of the electro-active species in fluid form3,4,5. Wide-scale utilization of flow batteries is, however, limited by the abundance and cost of these materials, particularly those using redox-active metals and precious-metal electrocatalysts6,7. Here we describe a class of energy storage materials that exploits the favourable chemical and electrochemical properties of a family of molecules known as quinones. The example we demonstrate is a metal-free flow battery based on the redox chemistry of 9,10-anthraquinone-2,7-disulphonic acid (AQDS). AQDS undergoes extremely rapid and reversible two-electron two-proton reduction on a glassy carbon electrode in sulphuric acid. An aqueous flow battery with inexpensive carbon electrodes, combining the quinone/hydroquinone couple with the Br2/Br− redox couple, yields a peak galvanic power density exceeding 0.6 W cm−2 at 1.3 A cm−2. Cycling of this quinone–bromide flow battery showed >99 per cent storage capacity retention per cycle. The organic anthraquinone species can be synthesized from inexpensive commodity chemicals8. This organic approach permits tuning of important properties such as the reduction potential and solubility by adding functional groups: for example, we demonstrate that the addition of two hydroxy groups to AQDS increases the open circuit potential of the cell by 11% and we describe a pathway for further increases in cell voltage. The use of π-aromatic redox-active organic molecules instead of redox-active metals represents a new and promising direction for realizing massive electrical energy storage at greatly reduced cost.

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A metal-free organic–inorganic aqueous flow battery

Reḿi Auvergne,† Sylvain Caillol,† Ghislain David,*,† Bernard Boutevin,† and Jean-Pierre Pascault‡,§ †Institut Charles Gerhardt UMR CNRS 5253 Laboratoire Ingeńierie et Architecture Macromolećulaire, Ecole Nationale Supeŕieure de Chimie de Montpellier, 8 rue de l’Ecole Normale, 34296 Montpellier Cedex 05, France ‡INSA-Lyon, IMP, UMR5223, F-69621, Villeurbanne, France Universite ́ de Lyon, F-69622, Lyon, France

Biobased thermosetting epoxy: present and future.

Recent developments in organic redox flow batteries: A critical review

An absorbent article comprising a central absorbent member and a lateral wicking barrier for inhibition of wicking from the central regions of the article to an outlying outer absorbent member. The wicking barrier has a vertical component for prevention of radial wicking in the plane of the article and thus promotes center filling of the article with fluid and reduces the likelihood of leaks from the sides of the article. The wicking barrier can also have a horizontal component to prevent leakage, redirect fluid flow, and improve fit and performance of the article. In one embodiment, the central absorbent member is a concentric absorbent structure having alternating rings of barrier material and absorbent material, including a spiral wound composite formed from a layer of barrier material wound with a layer of absorbent material and then sliced to provide a thin absorbent layer having high permeability in the thickness direction but low permeability in the plane due to the barrier material.

Absorbent article with center fill performance

The present invention discloses a disposable scrubbing product for use in household cleaning or personal care applications. In one embodiment, the present invention is directed to a cleaning tool including a handle and a rigid base to which the scrubbing product of the present invention may be attached to form a convenient cleaning tool. The scrubbing product of the invention is a multi-layer laminate product and generally includes at least two distinct layers, an abrasive layer (32) and an absorbent fibrous layer (34) such as a layer tissue made from papermaking fibers, a layer of coform, an airlaid web, or combinations thereof. The abrasive layer (32) is formed primarily of polymeric fibers in a disordered or random distribution as is typical of fibers deposited in meltblown or spunbond processes so as to form an open, porous structure. In one embodiment, the abrasive layer (32) comprises multifilamentary aggregate fibers. In one embodiment, the absorbent fibrous (34) layer is an uncreped, through dried paper web.

Disposable scrubbing product

For the production of cellulose from wood and annual plants, a boiling process is proposed in which the boiling liquor contains free soda lye and sodium salts of the alkylbenzole sulphonic acids or aromatic and aliphatic carboxylic acids. Delignification is reinforced on the addition of anthraquinone or its derivatives to the boiling liquor. There is no need to restrict the quantities of the anthraquinone additive owing to its price since anthraquinone resists wet oxidation and can be recycled in the boiling process. The solubility and hence the effect of the anthraquinone is enhanced by the use of sulphonic acid salts. In order to recover the processing chemicals contained in the black liquor it is proposed that the dissolved lignin be precipitated with mineral or carboxylic acid, the hemi-celluloses be separated by ultra-filtration and the resins by extraction, where appropriate, and the remaining organic components except for the sulphonic and carboxylic acids salts be burned in the aqueous phase with air and/or oxygen. The chemical solution freed from the wood decomposition products may be returned to the liquor after caustification of the carbonates and, after the partial crystallisation of the aliphatic carboxylic acid salts, made available in the circuit for cellulose production. The sodium acetate isolated by crystallisation can be broken down into acetic acid and sodium hydroxide by diaphragm electrolysis. The soda lye is returned to the boiling process and the acetic acid treated separately.

Production of cellulose by the soda-anthraquinone process (sap) with recovery of the boiling chemicals

In order to recover inorganic chemicals from waste liquors in cellulose manufacturing processes it is proposed to separate the alkali or alkaline earth from the organic components by partial or complete oxidation in the aqueous phase with air and/or oxygen. Before this oxidation process, it is possible to separate the lignin in the black liquor by acidification and precipitation with a mineral acid, the resins by extraction and the demi-celluloses by ultra-filtration, whereupon the residual organic substances still remaining in solution are oxidised. Wet oxidation is possible such that the carboxylic acids, especially the acetic acid, is not burned as well and can be separated by crystallisation after caustification. The chemical solution thus freed of organic substances can be returned to the liquor by caustification and made available in the cellulose production cycle.

Otto W. Gordon

Papers

Production of cellulose by the soda-anthraquinone process (sap) with recovery of the boiling chemicals

Process for the recovery of processing chemicals from the black liquor in the production of cellulose by organo-solvent processes

Production of cellulose and recovery of chemicals