Called a vanadium redox flow battery (VRFB), it's cheaper, safer and longer-lasting than lithium-ion cells. Here's why they may be a big part of the future — and why you may never see one. In the 1970s, during an era of energy price shocks, NASA began designing a new type of liquid battery.
Since the concept of vanadium battery was firstly proposed, the relevant technology and patents have been controlled by vanadium battery manufacturers in Japan, Canada, who impose the technical blockade to Chinese enterprises, leading to a retard start of research and application in China.
As a result, vanadium batteries currently have a higher upfront cost than lithium-ion batteries with the same capacity. Since they're big, heavy and expensive to buy, the use of vanadium batteries may be limited to industrial and grid applications.
Since vanadium can exsist in four different oxidation states, the positive half cell employs VO2 + /VO 2+ while the negative half cell contains V 2 + /V 3 +. When the vanadium battery is charged, the VO 2 + ions in the positive half cell are converted to VO 2+ ions when electrons are removed from the positive terminal of the battery.
It is estimated that about 20 patents on vanadium battery are applied and approved in China, which mainly focus on the preparation of the electrolyte. Chinese domestic enterprises and research institutions have close cooperation in the vanadium battery technology research.
And second, if some of the vanadium in one tank flows through the membrane to the other side, there is no permanent cross-contamination of the electrolytes, only a shift in the oxidation states, which is easily remediated by re-balancing the electrolyte volumes and restoring the oxidation state via a minor charge step.