All-vanadium redox flow battery SOC detection method based on thermochemistry measurement

Abstract

The invention relates to the field of all-vanadium redox flow batteries, and specifically discloses an all-vanadium redox flow battery SOC detection method based on thermochemistry measurement. For the requirements on the real-time detection of SOC (State-of-charge) state of positive and negative electrodes in the using process of an all-vanadium redox flow battery, the specific heat capacity anddensity of positive and negative electrode electrolytes, the inner resistances of positive and negative electrodes and the enthalpy changes of positive and negative electrode reactions at different temperatures are measured in an offline manner, energy conservation equations are established for the positive and negative electrodes inside an electric pile by using the first law of thermodynamics, the inlet and outlet electrolyte temperature changes of the positive and negative electrodes of the electric pile are associated with the heat changes of reactions, the inlet and outlet electrolyte temperature changes of the positive and negative electrodes of the electric pile, reaction current and electrolyte flow rate are measured in real time in an online manner, the heat changes of the positive and negative electrode reactions inside a sampling time period are calculated in real time, and the substance concentration change rule of adjacent sampling points is calculated and obtained in combination with the enthalpy change values of the positive and negative electrode reactions at specific reactions obtained in the offline manner, so that real-time detection for SOC is realized.

Description

Technical field [0001] The invention relates to the field of all-vanadium redox flow batteries, in particular to a state-of-charge (SOC) detection method for all-vanadium redox batteries based on thermochemical measurement. Background technique [0002] The vanadium flow battery is one of the first choices for large-scale energy storage technology. Real-time detection of SOC status is very important. An efficient SOC online detection method can effectively increase the utilization rate of capacity and avoid the corrosion and corrosion of electrode materials due to side reactions. damage. At present, the open circuit voltage method is mainly used in the project to estimate the SOC state of the positive and negative electrodes of the battery by collecting the voltage; at the same time, although many SOC detection methods based on spectroscopy, electrolyte conductivity, and absorbance can be used for the laboratory low-power level of vanadium Flow battery system, but due to the lim...

AI Technical Summary

Problems solved by technology

At present, the open circuit voltage method is mainly used in engineering to estimate the SOC state of the positive and negative electrodes of the battery by collecting voltage; at the same time, although many SOC detection methods based on spectrum, electrolyte conductivity, absorbance, etc. can be used for low-power all-vanadium in the laboratory Flow battery system, but due to the limitation of the instrument, it cannot be effectively applied to the all-vanadium flow battery system for engineering applications

Images