Lithium Iron Phosphate (LFP)

Lithium Iron Phosphate (LFP or LiFePO₄) is a type of lithium-ion battery chemistry that uses iron phosphate as the cathode material. LFP batteries are increasingly popular for residential solar storage due to their excellent safety, long cycle life, and thermal stability.

LFP batteries offer several advantages over other lithium-ion chemistries. They are inherently more stable and resistant to thermal runaway (overheating and fire), making them one of the safest battery options for home installation. They also have an exceptionally long cycle life — typically 5,000–10,000+ cycles — which translates to 15–25 years of daily use. The trade-off is a lower energy density compared to NMC batteries, meaning LFP batteries are physically larger and heavier for the same capacity. However, for stationary home storage where weight and size are less critical than safety and longevity, LFP is an excellent choice. The Tesla Powerwall 3, Enphase IQ Battery 5P, and many Sol-Ark compatible batteries use LFP chemistry. LFP batteries also use abundant, non-toxic materials (iron and phosphate) instead of cobalt and nickel, making them more environmentally friendly and less subject to supply chain concerns.