Flow battery

A flow battery comprising:

• a first liquid containing a lithium ion and a first redox material;
• a first electrode in contact with the first liquid;
• a second electrode functioning as a counter electrode of the first electrode;
• an isolation unit that isolates the first electrode and the second electrode from each other;
• a first chamber;
• a first circulation mechanism for circulating the first liquid between the first electrode and the first chamber;
• a second liquid containing a second redox material;
• and
• a second active material immersed in the second liquid,
• wherein:
• the first liquid is non-aqueous,
• the first circulation mechanism includes a magnetically driven pump,
• the magnetically driven pump includes a casing and an impeller,
• an inner surface of the casing is formed of a resin nonreactive with lithium,
• a surface of the impeller is formed of the resin nonreactive with lithium,
• the second electrode is in contact with the second liquid,
• the isolation unit isolates the first electrode from the second electrode,
• the isolation unit isolates the first liquid from the second liquid,
• the second redox material is oxidized or reduced on the second electrode,
• the second redox material is oxidized or reduced by the second active material, and
• the second redox material is tetrathiafulvalene.