SOFI is high right now maybe 4% but I love my capital one, a little lower, but they always fluctuate up and down with the market instead of staying at a certain rate, so always give you a good price. All their accounts are free no matter how much you have in them so I stick with them!
Ally. The bucket feature is awesome, and it allows me to earn interest on ALL of my sinking funds combined while still conceptualizing them as separate entities. Recommend pairing this with an Ally checking account so you can easily transfer money when needed for usage.
Synchrony. It’s the only online bank we’ve tried, but the rate is good and it’s really easy to set up more accounts. It comes with a debit card. The downfall is 3ish days to transfer money, but I get the impression that’s standard with other online banks too.
Just remember that your EF is not meant to be an investment. Earning interest is a bonus and I hope these higher rates hold, but your main concern should be liquidity/ease of access when an emergency happens.