The prospects of zinc flow batteries

What is a zinc-based flow battery?

The history of zinc-based flow batteries is longer than that of the vanadium flow battery but has only a handful of demonstration systems. The currently available demo and application for zinc-based flow batteries are zinc-bromine flow batteries, alkaline zinc-iron flow batteries, and alkaline zinc-nickel flow batteries.

What are the advantages of zinc-based flow batteries?

Benefiting from the uniform zinc plating and materials optimization, the areal capacity of zinc-based flow batteries has been remarkably improved, e.g., 435 mAh cm-2 for a single alkaline zinc-iron flow battery, 240 mAh cm -2 for an alkaline zinc-iron flow battery cell stack , 240 mAh cm -2 for a single zinc-iodine flow battery .

How much does a zinc flow battery cost?

In addition to the energy density, the low cost of zinc-based flow batteries and electrolyte cost in particular provides them a very competitive capital cost. Taking the zinc-iron flow battery as an example, a capital cost of $95 per kWh can be achieved based on a 0.1 MW/0.8 MWh system that works at the current density of 100 mA cm-2 .

Can a zinc-based flow battery withstand corrosion?

Although the corrosion of zinc metal can be alleviated by using additives to form protective layers on the surface of zinc [14, 15], it cannot resolve this issue essentially, which has challenged the practical application of zinc-based flow batteries.