Porous electrode assembly, liquid-flow half-cell and liquid-flow cell stack

Abstract

The invention provides a porous electrode assembly, a liquid-flow half-cell and a liquid-flow cell stack. The porous electrode assembly comprises a plurality of porous electrodes which are superimposed, wherein at least one porous electrode is a channel electrode with a flow channel, and the flow channel runs through the channel electrode in the thickness direction. At least one porous electrode of the porous electrode assembly is a channel electrode with an inner flow channel through which an electrolyte can flow, and the electrolyte flows in the porous electrode with the flow channel under the guide effect of the flow channel, so that the surface area for the electrolyte to permeate the solid part of the porous electrode is increased, the liquid flow resistance of the porous electrode for the flowing of the electrolyte can be reduced, and the liquid flow pressure difference needed by the flowing of the electrolyte can be effectively reduced; and moreover, when the electrolyte flows in the flow channel, the electrolyte uniformly permeates the porous electrodes on two sides of the flow channel, so that the uniformity for the flowing of the liquid flow can be improved, concentration difference polarization caused by the flowing of the electrolyte can be reduced, and the charging-discharging efficiency of a liquid flow cell with the porous electrode assembly can be improved.

Description

technical field [0001] The invention relates to the field of liquid flow battery design, in particular to a porous electrode group, a liquid flow half-cell and a liquid flow battery stack. Background technique [0002] The all-vanadium redox flow battery is an electrochemical reaction device that performs redox with vanadium ion electrolytes in different valence states, and can efficiently realize the mutual conversion between chemical energy and electrical energy. This type of battery has the advantages of long service life, high energy conversion efficiency, good safety, and environmental friendliness. It can be used in large-scale energy storage systems for wind power generation and photovoltaic power generation. It is the main choice for power grid peak shaving and valley filling and load balancing one. Therefore, in recent years, all-vanadium redox flow batteries have gradually become the focus of research on large-capacity energy storage batteries. [0003] All-vanad...

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Problems solved by technology

[0004] The flow of electrolyte in the existing flow battery stack generally depends on the permeation and mass transfer of porous electrodes. The efficiency of the battery system is reduced; on the other hand, the electrolyte flow inside the battery stack is uneven and the concentration polarization is large, which causes the internal loss of the battery stack, thereby reducing the voltage efficiency of the battery

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