Lithium-ion (Li-ion) and lithium iron phosphate (LiFePO₄ or LFP) batteries are among the most widely used battery technologies worldwide today. Hardly any application that relies on stored energy can do without one of these two technologies. The following characteristics help in selecting the optimal battery technology for each specific application.

1. Energy density

Energy density indicates how much energy a battery can store per unit of weight (Wh/kg). Lithium-ion batteries typically have a high energy density of 150–250 kWh/kg. Wh/kg. This makes them lighter and more compact, and particularly suitable for devices where weight and size are crucial, such as e-bikes, laptops, battery-powered tools, or drones.

LiFePO₄ batteries have a lower energy density of about 90–140 Wh/kg. This means that battery solutions with the same amount of energy will be almost twice as heavy as Li-ion batteries.

2. Nominal voltage

Li-ion battery cells typically have a nominal voltage of 3.6–3.7 V. V, while LiFePO₄ cells with 3.2–3.3 V should be slightly lower.

For larger battery systems, the individual cells are connected both in series (S) and in parallel ( P ). A series connection increases the nominal voltage, while a parallel connection increases the total capacity. The structure of a battery can be represented by the notation "X". S Y P “ is represented, where X indicates the number of cells connected in series and Y the number of cells connected in parallel.

The permissible operating voltage of a device often determines which battery technology is used. Devices that typically operate with 6 V-type vehicles are generally powered by 2S LiFePO₄ batteries , since the nominal voltage of a 2S Li-ion battery is already 7.2–7.4 V. V is too high.

3. Safety

LiFePO₄ batteries are considered particularly safe because their chemistry is thermally very stable. The risk of a "thermal runaway" —a condition in which the cell temperature rises uncontrollably and chemical reactions can cause fire, smoke, or explosion—is virtually eliminated with LFP batteries.

In contrast, Li-ion battery cells are less thermally stable and pose a higher risk of overheating or fire, especially if they are damaged or charged incorrectly.

Therefore, it is crucial to use battery cells from reputable manufacturers . Reputable manufacturers also have their energy storage elements certified by independent testing laboratories. Well-known standards include UL and IEC 62133. IEC 62133 is an international safety standard, while UL is a North American certification. Many manufacturers have their batteries tested according to both standards to ensure global marketability.

For Li-ion batteries, we exclusively use high-quality cells from LG Energy, Samsung SDI, Molicel or Murata (formerly Sony).
For LiFePO₄ batteries, we use cells from Haidi Energy , one of the world's largest manufacturers of LiFePO₄ battery cells.

4. Service life or cycle stability

LiFePO₄ batteries offer a significantly longer lifespan. While Li-ion batteries typically achieve 300 to 1,000 charge cycles, LFP batteries can easily handle 2,000 to 7,000 cycles and age considerably more slowly.

For this reason, LiFePO₄ batteries are frequently used in large and expensive battery solutions such as storage systems, balcony power plants or electric cars .
It should be mentioned here that we are deliberately omitting the topic of "lifespan optimization through Battery Management Systems (BMS)" and possible modifications.

5. Behavior depending on temperature

In terms of their basic function, LiFePO₄ and Li-ion batteries differ only slightly.

• Heat: LiFePO₄ batteries tolerate high temperatures better and are very thermally stable, while Li-ion batteries are more sensitive.
• Cold: LiFePO₄ batteries are limited when charging at very low temperatures, while only a few manufacturers offer particularly robust Li-ion batteries that can also be charged below -20°C. °C can be charged and discharged.