>>28514174>Lithium fires burn hot enough to rip oxygen out of other compounds, so you can't suffocate them They can't get hot enough to break CO2 bonds, hence why suffocating agents (carbonate-based, which generate CO2 when heated) are used on metal fires.
My suffocating recipe above is a cheaper variant of what pretty much every professional recommends for such fires (percentages might need a bit of tweaking).