Are all lithium batteries the same?

🔋 When it comes to photovoltaic storage, it's common to talk about lithium batteries in general, but in reality, not all lithium batteries are the same. The name given to these batteries is based on their design, where lithium ions are allowed to travel between different electrodes. However, depending on the cathode, we can find different types of technologies with differentiated characteristics and applications.

☀️ Today, the most widespread ones in the photovoltaic sector are lithium iron phosphate (LFP) with brands like BYD or Huawei and lithium nickel-manganese-cobalt (NMC) with brands like Samsung. But practically speaking, how do they differ?

NMC - They have a higher energy density (more capacity in less space).

LFP - They have lower degradation with use, are more stable and safe, and do not require rare metals like cobalt, making them cheaper and more environmentally friendly.

📉 The degradation process of a battery is complex because a variety of factors influence it, such as the number of cycles, depth of discharge, and temperature.

In the image, you can see the degradation evolution of an NMC battery and an LFP battery over 25 years with typical self-consumption use. As you can see, LFP technology loses 20% of capacity, while NMC technology loses 45%.

Both durability in charge/discharge cycles and safety are crucial in self-consumption applications. In fact, companies like Tesla are starting to use LFP even for non-stationary applications (in their electric cars).

Knowing that photovoltaic installations for self-consumption will be operating for decades, it is important to consider all these variables (don't worry, they are already taken into account at https://ieco.io). 😉