Lithium Iron Phosphate

A battery is a storage device for electricity that can be recharged again and again. Inside it are two electrodes made of different materials. Which materials these are determines the price, lifespan, and weight of the battery. Lithium iron phosphate is one of these materials and sits at the positive electrode. As the name suggests, it consists of lithium, iron, and phosphate, i.e. relatively common and cheap raw materials. Batteries with this material are usually called LFP for short and today are found in many electric cars and energy storage systems.

Why iron instead of cobalt has shifted the market

The long-standard alternative is called NMC. There, the positive electrode consists of nickel, manganese, and cobalt. Cobalt is expensive and is largely mined in the Congo, often under very poor working conditions. Nickel is also expensive and its price fluctuates strongly. Iron and phosphate, by contrast, cost a fraction of that and are available almost everywhere.

This has a direct effect on the price of an electric car. The battery is the most expensive single component, often a third of manufacturing costs. Affordable entry-level models from many manufacturers have only become possible thanks to LFP. According to industry estimates, well over half of all new batteries worldwide are now built with this material.

Then there is safety. LFP cells withstand higher temperatures before they ignite on their own. A runaway battery fire is therefore less likely than with nickel-rich cells. For storage systems that sit in a basement or warehouse for years, this is a decisive argument.

What happens inside the cell

During charging, tiny lithium particles migrate from the positive electrode to the negative electrode. During discharging, they move back, driving the current through the connected device. The positive electrode is thus a kind of parking lot for lithium. Lithium iron phosphate has a very stable crystal lattice that barely deforms during this parking and unparking.

This is exactly where the long lifespan comes from. An LFP battery often survives several thousand full charge cycles before its capacity noticeably declines. Nickel-rich cells usually manage significantly fewer. LFP can also be charged regularly to 100 percent without damaging it quickly.

The downside lies in the same stable lattice. It binds less energy per kilogram, typically around 20 to 30 percent less than NMC. For the same range, a car therefore needs a heavier battery. In cold weather, there’s a second drawback: below zero degrees, LFP charges more slowly and delivers less power. A common misconception is that LFP is simply the inferior technology. More accurately, it is a trade-off of weight for price and durability.

From standard cars to home storage

In the automotive world, LFP is mainly found in the cheaper variants. Tesla's standard versions, many BYD models, and numerous entry-level VW cars use it. The range champions with over 600 kilometers, however, continue to rely on nickel-rich cells, because there every kilogram counts.

The situation is even clearer with large energy storage systems. Such systems buffer solar power from midday for use in the evening. They stay fixed in one place, so weight doesn’t matter. Price, safety, and lifespan are decisive, and there LFP wins almost every time. Home storage systems in the basement of a single-family house today also mostly use this technology.

That’s why the term regularly appears in business news. It usually concerns factories for LFP cells, patents, or raw material prices. Anyone reading such reports should know: behind the abbreviation lies a deliberate choice of cheap raw materials over maximum range.