Lithium iron phosphate batteries: Science and technology

How dropping cobalt and nickel buys safety and long life

LFP stores energy by moving lithium ions between a graphite anode and an iron phosphate cathode. It gives up some energy density compared with nickel chemistries, but it avoids cobalt and nickel and lasts longer, which is why it now dominates stationary storage.

Mechanism

Charging pulls lithium ions out of the iron phosphate crystal and pushes them into the layers of a graphite anode (intercalation, meaning ions slot into a host structure without destroying it). Discharge reverses the flow, and electrons travel through the external circuit to do work. The phosphate structure binds oxygen tightly, so the cathode is chemically steadier than layered nickel oxides, but it holds less energy per kilogram. That trade-off matters little for grid batteries, where weight is not a constraint; LFP went from about 80% of new battery storage in 2023 to more than nine in ten installations in 2025.²¹⁷

Material scarcity and toxicity

LFP needs no cobalt or nickel, the two battery metals with the worst supply and human-rights records. It still needs lithium and graphite, and both supply chains are highly concentrated: China refines about 70% of lithium chemicals and over 95% of battery-grade graphite, and makes nearly all LFP cathode capacity. China proposed licensing exports of LFP cathode production technology in January 2025 and put it on its restricted export list in July 2025, so building plants elsewhere now needs Chinese approval for that know-how. Iron and phosphate are abundant and of low toxicity; the main hazards are the flammable organic electrolyte and fluorinated salts.²³⁴⁵

Degradation and ageing

Capacity fades mainly as the protective film on the graphite (the solid electrolyte interphase) slowly thickens and consumes lithium, and faster if cells are charged hard in the cold (lithium plating) or kept full and hot. A 2026 EU study reports typical LFP cycle life of 6,000 to over 10,000 cycles, with some cells near 12,000 under controlled conditions. An older 2020 US grid assessment assumed only about 2,000 cycles at 80% depth of discharge and a 10-year life; the gap reflects improvement in cells since then and the conservative warranty basis of the older figure. NREL now models a 15-year project with augmentation (adding modules over time) to hold rated capacity.⁶¹⁰¹¹

LFP against the main alternatives¹²

Sources

1. Lithium-Ion Battery Pack Prices Fall to $108 per Kilowatt-Hour, Despite Rising Metal Prices BloombergNEF, 2025
2. Global EV Outlook 2026: Electric vehicle batteries International Energy Agency, 2026
3. China revises catalogue of technologies subject to export controls (battery cathode material preparation technology added, 15 July 2025) Shanghai Municipal People's Government (reporting China's Ministry of Commerce), 2025
4. Diversification is the cornerstone of energy security, yet critical minerals are moving in the opposite direction (Global Critical Minerals Outlook 2025) International Energy Agency, 2025
5. Global Critical Minerals Outlook 2025 International Energy Agency, 2025
6. Annual Technology Baseline 2025: Utility-Scale Battery Storage National Laboratory of the Rockies (formerly NREL), 2025
7. Energy resilience of households in a prepared union: the potential of a sodium battery-based solution European Economic and Social Committee, 2026
8. Lithium-ion Battery methodology, 2020 Grid Energy Storage Technology Cost and Performance Assessment PNNL / US DOE, 2020
9. Batteries and Secure Energy Transitions: Executive summary International Energy Agency, 2024