The all-vanadium redox flow battery (VRFB) is emerging as a promising technology for large-scale energy storage systems due to its scalability and flexibility, high round-trip efficiency, long durability, and little environmental impact. 

VRFB's main advantages:

no limit on energy capacity

can remain discharged indefinitely without damage

mixing electrolytes causes no permanent damage

single charge state across the electrolytes avoids capacity degradation

safe, non-flammable aqueous electrolyte;

wide operating temperature range including passive cooling

long charge/discharge cycle lives: 15,000-20,000 cycles.

low levelized cost: (a few tens of cents), approaching the $0.05 targets stated by the US Department of Energy and the European Commission Strategic Energy Technology Plan (€0.05), respectively.