In flow batteries, high depth of discharge is possible which means most of its nominal capacity can be discharged without imposing any permanent damage to the cell structure 22. In addition, they can store electroactive materials required for battery operation in a tank outside the battery structure.
SECTION 5: FLOW BATTERIES K. Webb ESE 471 2Flow Battery Overview K. Webb ESE 471 3 Flow Batteries Flow batteries are electrochemical cells, in which the reacting substances are stored in electrolyte solutions external to the battery cell Electrolytes are pumped through the cells Electrolytes flow across the electrodes
Other flow-type batteries include the zinc–cerium battery, the zinc–bromine battery, and the hydrogen–bromine battery. A membraneless battery relies on laminar flow in which two liquids are pumped through a channel, where they undergo electrochemical reactions to store or release energy. The solutions pass in parallel, with little mixing.
Compared to the flow-by configura-tion, an undivided battery with flow-through electrodes may assure enhanced mass transport. However, the flow rate will be largely limited. A laminar flow battery using two-liquid flowing media, pumped through a slim channel without lateral mixing or with very little mixing, enables membrane-free operation.
Due to the minor change during a single cycle, the battery capacity was considered constant during each charge and discharge cycle and was determined at the end of the charge cycle as the battery capacity of that cycle. The recorded capacity was called the maximum capacity in a charge and discharging profile.
4 Flow Batteries Flow batteries comprise two components: Electrochemical cell Conversion between chemical and electrical energy External electrolyte storage tanks Energy storage Source: EPRI K. Webb ESE 471 5 Flow Battery Electrochemical Cell Electrochemical cell Two half-cellsseparated by a proton-exchange membrane(PEM)