The realization of a flow battery having a high energy density is desired in the prior art. This flow battery is provided with: a first liquid in which a condensed aromatic compound and lithium are dissolved; a first electrode which is immersed in the first liquid; and a first circulation mechanism provided with a first accommodation part and a first passage inhibiting part. The first liquid in which the condensed aromatic compound is dissolved exhibits the properties of releasing solvated electrons of the lithium, and dissolving the lithium as cations. The lithium dissolved in the first liquid is deposited on the first electrode, and, as a result, deposited lithium particles are formed. The first circulation mechanism circulates the first liquid between the first electrode and the first accommodation part. The first circulation mechanism moves the deposited lithium particles formed on the first electrode to the first accommodation part. The first passage inhibiting part is provided inthe path along which the first liquid flows out from the first accommodation part to the first electrode, and inhibits passage of the deposited lithium particles.