Is there any electric aircraft certified by the FAA? It depends on your definition of "aircraft." The FAA has certified several unmanned electric aircraft such as the Matternet M2, Aerovironment PUMA AE, and Airobotics OPTIMUS 1-EX. However, no manned electric aircraft has been certified at this time.
It's not for lack of interest from manufacturers. There are many companies working towards certifying electric aircraft. Pipistrel has applied for FAA approval and is working towards a certification. The issue is that this is a new type of aircraft (or at least propulsion) and the FAA works slowly. In addition to the usual concerns of certification, the FAA would probably like to avoid any high-profile issues, as recent history has shown how quickly people can lose trust, especially with a new technology like electric aircraft.
Can the Pipistrel Velis Electro currently fly in the USA? It depends on your definition of "fly." It's already flying in the US under experimental rules. It would need FAA certification to fly commercially though. The US Air Force will also be experimenting with it, which also doesn't necessarily require FAA certification.
The FAA has been working towards rule changes for smaller aircraft that would make it easier to certify them, including these kinds of electric aircraft. Another type of electric aircraft with lots of interest is eVTOL (electric Vertical Take Off and Landing) and the FAA is looking at creating a new category to certify those.
And it's not just the FAA that's moving slowly. The Velis Electro is apparently still the only electric aircraft with EASA certification. A lot has been going on in the world in the last 4 years and continues to occur. Yet still technology moves much faster than regulations and as both continue to advance there will likely be more electric aircraft being certified. Not as soon as many would like, but with time the industry will grow.