Electrolyte measurement method and electrolyte measurement device for vanadium redox flow battery

Abstract

The invention relates to an electrolyte measurement method and an electrolyte measurement device for a vanadium redox flow battery. The electrolyte measurement method comprises the following steps of: measuring the absorption or transmission spectra of a plurality of groups of electrolyte samples with known configuration parameters under the irradiation of a set light waveband, recording the absorption or transmission spectra of the groups of electrolyte samples, and establishing a standard spectral database; in the light waveband, measuring the absorption or transmission spectrum of an electrolyte to be measured; finding out a spectrum closest to the measured spectrum from the standard spectral database; and determining configuration parameters corresponding to the closest spectrum to be measured parameters of the electrolyte to be measured. With the adoption of the electrolyte measurement method and the electrolyte measurement device for the vanadium redox flow battery, the concentrations of vanadium ions of various valences in the electrolyte of the vanadium battery can be effectively measured in an on-line manner, the measurement manner is simple, and the speed is fast.

Description

technical field [0001] The invention belongs to the technical field of material measurement, and in particular relates to an electrolyte detection method and a detection device of an all-vanadium redox flow battery based on optical absorption. Background technique [0002] Flow batteries have the characteristics of high design power, long service life, and no pollution, and are an important choice for large-scale energy storage systems. Among them, vanadium redox flow battery (Vanadium Redox Flow battery, referred to as VRB or vanadium battery) is currently the most concerned type of flow battery at home and abroad (J. Electrochem. Soc. 1986, 133:1057). [0003] In vanadium batteries, the working substances in the positive and negative electrodes are electrolytes containing vanadium ions. During the charging process, the +4-valent vanadium ions in the positive electrode are transformed into +5-valent vanadium ions, and the +3-valent vanadium ions in the negative electrode a...

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Problems solved by technology

[0006] (2) The ion exchange membrane used in vanadium batteries cannot completely prevent the penetration of vanadium ions, and different osmotic pressures will cause volume changes in the positive and negative electrolytes

However, the concentration of vanadium ions in the electrolyte of vanadium batteries is too high (generally up to 2mol / L), the absorption coefficient is too large, and there is interference between vanadium ions in different valence states, the absorption coefficient of a single wavelength is linearly related to different ion concentrations

Therefore, the traditional spectrophotometer method based on the absorption coefficient of a single wavelength can only measure the concentration of the negative electrolyte of some vanadium batteries to a limited extent, but cannot measure the positive electrolyte (Journal of Power Sources 2011, 196: 8822–8827, WO9003666)

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