Bipolar plate for flow battery, flow battery and battery stack

The invention relates to the field of flow cells, in particular to a bipolar plate for a flow cell, the flow cell and a cell stack, the bipolar plate is provided with an electrolyte inlet part and an electrolyte outlet part, the bipolar plate is not provided with an electrolyte flow channel, and the surface roughness Ra of the bipolar plate is 0.05-12.5 microns; wherein the electrolyte inlet part is sequentially divided into a first straight cylinder section and a diameter expanding section in the flowing direction of the electrolyte; and the electrolyte outlet part is sequentially divided into a reducing section and a second straight barrel section. The bipolar plate for the flow battery provided by the invention has the advantages of excellent preparation performance, simple process, low cost and environmental friendliness; the bipolar plate provided by the invention is assembled into a flow battery, and the battery shows excellent electrochemical performance. 本发明涉及液流电池领域，具体涉及一种液流电池用双极板、液流电池以及电池堆，该双极板上设置有电解