Using a mandoline slicer or a sharp knife, slice the peeled sweet potatoes into very thin rounds, about 1/16 inch thick.
Place the sweet potato slices in a large bowl and drizzle with olive oil. Toss gently to coat all slices evenly.
Sprinkle the sea salt over the slices and toss again to distribute the seasoning.
Preheat the air fryer to 130°F (54°C) if it has a dehydration setting. If not, set it to the lowest temperature possible, ideally between 120°F and 140°F (49°C to 60°C).
Arrange the sweet potato slices in a single layer in the air fryer basket or tray, making sure they do not overlap. You may need to work in batches.
Dehydrate the sweet potato slices in the air fryer for 40 to 45 minutes, checking every 15 minutes to flip the slices and ensure even drying.
The chips are done when they are crisp and no longer flexible. If they are still soft, continue dehydrating in 5-minute increments.
Remove the dehydrated sweet potato chips from the air fryer and let them cool completely on a wire rack to maintain crispness.
Serve immediately or store in an airtight container once fully cooled.