Flow Batteries: Current Status and Trends

Research on redox-flow batteries (RFBs) is currently experiencing a significant upturn, stimulated by the growing need to store increasing quantities of sustainably generated electrical energy. RFBs are promising candidates for the creation of smart grids, particularly when combined with photovoltaics and wind farms. To achieve the goal of "green", safe, and cost-efficient energy storage, research has shifted from metal-based materials to organic active materials in recent years. This Review presents an overview of various flow-battery systems. Relevant studies concerning their history are discussed as well as their development over the last few years from the classical inorganic, to organic/inorganic, to RFBs with organic redox-active cathode and anode materials. Available technologies are analyzed in terms of their technical, economic, and environmental aspects; the advantages and limitations of these systems are also discussed. Further technological challenges and prospective research possibilities are highlighted.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.201604925

Redox-Flow Batteries: From Metals to Organic Redox-Active Materials

The development of various redox-flow batteries for the storage of fluctuating renewable energy has intensified in recent years because of their peculiar ability to be scaled separately in terms of energy and power, and therefore potentially to reduce the costs of energy storage. This has resulted in a considerable increase in the number of publications on redox-flow batteries. This was a motivation to present a comprehensive and critical overview of the features of this type of batteries, focusing mainly on the chemistry of electrolytes and introducing a thorough systematic classification to reveal their potential for future development.

The Chemistry of Redox-Flow Batteries.

We present a time-correlated single photon counting (TCPSC) technique that allows time-resolved multi-wavelength imaging in conjunction with a laser scanning microscope and a pulsed excitation source. The technique is based on a four-dimensional histogramming process that records the photon density over the time of the fluorescence decay, the x-y coordinates of the scanning area, and the wavelength. The histogramming process avoids any time gating or wavelength scanning and, therefore, yields a near-perfect counting efficiency. The time resolution is limited only by the transit time spread of the detector. The technique can be used with almost any confocal or two-photon laser scanning microscope and works at any scanning rate. We demonstrate the application to samples stained with several dyes and to CFP-YFP FRET.

Fluorescence lifetime imaging by time‐correlated single‐photon counting

A TEMPO-based non-aqueous electrolyte with the TEMPO concentration as high as 2.0 m is demonstrated as a high-energy-density catholyte for redox flow battery applications. With a hybrid anode, Li|TEMPO flow cells using this electrolyte deliver an energy efficiency of ca. 70% and an impressively high energy density of 126 W h L(-1) .

TEMPO-Based Catholyte for High-Energy Density Nonaqueous Redox Flow Batteries

A multi-stack simulation of shunt currents in vanadium redox flow batteries

1,3-Dioxolane, tetrahydrofuran, acetylacetone and dimethyl sulfoxide as solvents for non-aqueous vanadium acetylacetonate redox-flow-batteries

Novel electrolyte rebalancing method for vanadium redox flow batteries

Development of carbon nanotube and graphite filled polyphenylene sulfide based bipolar plates for all-vanadium redox flow batteries

The invention relates to a method for optical excitation of fluorophore-marked DNA and fluorophore-marked RNA, especially specific localizations of DNA and RNA, which are marked by fluorescence in situ hybridation (FISH). The aim of the inventive method is to provide easy high-contrast, simultaneous excitation of several FISH fluorophores which are to be detected and which can be represented in 3D, exhibiting various fluorescent characteristics. The excitation and detection of said fluorophores should be guaranteed at a depth of more than 100 micrometers in said biological material. According to the invention, the fluorescence of the FISH fluorophores and DNA markers is excited by means of multiphoton excitation in a simultaneous manner with pulsed or non-pulsed radiation at a wavelength ranging from 700nm to 1000nm, preferably 760nm and 820 nm. A total of 20 FISH fluorophores and DNA markers which are available on the market were tested. In all of the cases examined, simultaneous detection of multiphoton-excited fluorophores was possible.

Peter Fischer

Papers

A multi-stack simulation of shunt currents in vanadium redox flow batteries

1,3-Dioxolane, tetrahydrofuran, acetylacetone and dimethyl sulfoxide as solvents for non-aqueous vanadium acetylacetonate redox-flow-batteries

Novel electrolyte rebalancing method for vanadium redox flow batteries

Development of carbon nanotube and graphite filled polyphenylene sulfide based bipolar plates for all-vanadium redox flow batteries

Method for optical excitation of fluorophore marked dna and rna