Laser welding technology was used in the stack assembly for the first time. It not only improved the reliability of the stack, but also achieved automation of the stack assembly, decreased the use of sealing materials, and reduced the cost of the stack.
“This new VFB stack technology not only maintains the high power density of conventional stacks but also reduces total cost by 40% compared to conventional stacks,” said Prof. Li.
The membranes used in conventional VFB stacks are mainly commercial perfluorosulfonic acid membranes characterized by high cost and relatively poor ion selectivity.
In contrast, the weldable, porous ionic conductive membranes adopted in this new generation of VFB stack technology can improve ionic selectivity and increase the capacity retention of the electrolyte. This type of membrane costs much less than perfluorosulfonic acid membranes.