Redox flow cell for storing electrical energy and use thereof

Abstract

The invention relates to a cost-effective and durable redox flow cell which uses less corrosive redox-active components. The redox flow cell includes a reaction cell having two electrode chambers forcatholyte and anolyte, each of which are connected to at least one fluid storage means, which are separated by an ion-conducting membrane, and which are provided with electrodes, wherein the electrodechambers are each filled with electrolyte solutions containing redox-active components dissolved or dispersed in an electrolyte solvent, as well as optionally containing conducting salts dissolved therein, as well as potentially further additives. The redox flow cell is characterised in that the anolyte contains a redox-active component having one to six groups of formula (I), or having one to six groups of formula (II) in the molecule, and in that the catholyte contains a redox-active component having one to six groups of formula (III) in the molecule or iron salts, or in that anolyte and catholyte contains a redox-active component having one to six groups of formula (I) or of formula (II) in combination with one to six groups of formula (III) in the molecule, wherein R1 is a covalent C-C bond or a bivalent bridge group, R2 and R3 independently represent alkyl, alkoxy, haloalkyl, cycloalkyl, aryl, aralkyl, heterocyclyl, halogen, hydroxy, amino, nitro or cyano groups, X represents a q-value inorganic or organic anion, b and c are independently whole numbers from 0 to 4, q is a whole number from 1 to 3, a is a number with the value of 2 / q, and R4, R5, R6 and R7 independently represent alkyl, cycloalkyl, aryl or aralkyl groups.

Description

technical field [0001] The present invention relates to redox flow batteries for storing electrical energy, which are also generally referred to as redox flow batteries or redox flow batteries. A redox flow battery consists of two polarity-specific chambers in which the redox-active chemical compound or the redox-active compound is present either dissolved in the electrolyte solvent or dispersed in the two chambers, respectively. , and the chamber is connected to the reservoir. In this way, two separate circuits are formed for redox-active compounds present eg dissolved in water or an organic solvent or dispersed in the electrolyte solvent, separated by the membrane between the polarity-specific chambers. Ion exchange between the two chambers takes place through the membrane. Background technique [0002] Batteries are particularly suitable for stationary storage applications, e.g. as buffer batteries for wind and solar power plants or as power and regulation reserves for ...

AI Technical Summary

Problems solved by technology

However, useful current densities in redox systems are limited to less than 5 mA / cm 2 And the maximum achievable capacity is less than 10Ah / l

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