Heat detectors come in two general forms, one uses a fusible link which melts at a predetermined temperature, then there are dual function type, which use a chamber with a small pinhole to activate on rate of temperature, they too incorporate a fusible link, making them dual purpose, the application depends on environmental conditions.
Smoke detectors also fall into two categories, photo electric and ionization, both can detect smoke, but one may be more sensitive to the particular type of smoke generated, as for the smoke generated for from a LiFePo4 fire, I can't, ar this time definitively answer that question, without further research.
Basically what I'm alluding to is, don't assume because there are protections installed, they will work as intended.
BTW, I am qualified in fire alarm inspection and testing.