svicar1, discerning the authenticity of a cell is more than just a matter of measuring capacity, discharge performance also matters, along with looks and shape of the cell.
While I am not going to say there's no chance to find AliExpress sellers trying to sell fake cells, certainly a bit of common sense matters. The AliExpress way of doing things encourages honest sellers, they don't see a dime until the customer has received and checked their packages. The ubiquity of customer reviews helps too.
Got a pair of 30Q cells from what was known as the Colaier Direct Sales Store months ago. Flawless performance in a Sofirn C8T FET flashlight.
Cheers 