Flow battery cell and metal-air flow battery

A flow battery cell comprising:

• a positive electrode chamber;
• a negative electrode chamber opposite the positive electrode chamber;
• and
• a separator configured to separate the positive electrode chamber and the negative electrode chamber, wherein
• the negative electrode chamber comprises:
• a negative-electrode flow path configured to distribute a slurry containing a metal active material and an electrolytic solution;
• and
• a negative electrode constituting a part of a wall face of the negative-electrode flow path, and
• the negative electrode is disposed along a direction intersecting with a gravity direction and below the separator in terms of the gravity direction and satisfies 5×10{circumflex over ( )}−9≤Dp{circumflex over ( )}2/η<2.5×10{circumflex over ( )}−7, where the slurry has a viscosity given by n Pas, and the metal active material has a particle diameter given by Dp m.