Hello,
We think so. At least, the supplier sheet specifies "Lithium Iron Phosphate (LiFePO4)".

Don't think it's a LiFePO4 battery. That's why the Jackery Explorer 1000 Plus is also bigger and heavier than the Explorer 1000 Pro. (14.5kg to 11.5kg) And this is the case with all Jackery Plus / Pro.