The lowest storage temp for LFP batteries is point of electrolyte freezing and is no higher than -30 degs C. It is usually lower than this with other additives often put in electrolyte. The ethylene carbonate solvent is weak link for freezing temp but with the LiPF6 lithum salt added the EC freezing point is brought down to below -30 degs C. Dimethyl Caronate, also often added to solvent, lowers freezing point more.
Most all Li-Ion batteries use EC for solvent in the electrolyte, with lithium hexafluorophosphate salt (LiPF6). Dimethyl Carbonate, DC is second most common additive.