So far the one LFP battery I have deployed has been operating properly but there were some initial compatibility issues - my solar regulator did not interact well with the BMS despite alleged compatibility. That cost me several hundred dollars in downstream equipment damage due to voltage surge.
I am watching the new solid-state lithium batteries with great interest.
> Even under frigid conditions, sodium-ion batteries can maintain a high degree of ion mobility within their electrolyte. This increased mobility ensures that the battery can continue to deliver reliable performance when temperatures drop.
https://nadionenergy.com/why-sodium-ion-batteries-perform-we....
Or is it temperature cycling that causes your problems?
For the most part I don't actually need batteries that work in the freezing cold, so much as survive it unmaintained for months at a time. I had solar panel damage last winter that allowed one battery to discharge enough to freeze. That is fatal to a standard flooded lead-acid battery.
If my test battery survives this winter then I will consider using the same type to replace lead-acid ones as they age out.