Your best bet is in Certificates of Deposit (commonly known as CDs). You won't get a ton, but they almost always beat a checking/savings account. You invest into them at a certain maturity; you can select to leave your money in there for 3 months, 6 months, 1 year, 5 years, 30 years, and some range in between those numbers; longer terms offer better rates (6 months might be ~0.50% where as 5 years might be 2%). You can find a
list of some of the higher paying ones here; use the "Products" drop-down list to select the length of time.
Be advised, most if not all CDs make it so that you're penalized some amount if you withdraw early, although in my experience this penalty will not eat into your principal investment, just reduce what you'd have earned from the interest.
Please read the terms closely just to be certain before investing in them, since this is your emergency fund, in an emergency, you don't want to have your hands tied if you end up needing to withdraw some/all of the money. If you used 1-year CDs, you could put your money in gradually at around 8% a month. Put 8% of your emergency funds into a 1-year CD, wait one month then put another 8% into a new 1-year CD, wait one month then put another 8% into a new 1-year CD, etc. This would allow you to have a maturing CD each month, so if you suddenly lose your job, you'll have portions of that money frequently available without risking any fees for early withdrawal of funds. This is a bit complicated and probably unnecessary though, but it's just an idea that I thought may inspire some plan you could tailor to your specific scenario more easily.
Overall though, I think CDs are probably a decent route to take.