Lithium-ion batteries are one of the most mature technologies for storing energy. However, as is well known, they degrade. Batteries have a degradation due to calendar life and battery cycling. That is, batteries lose capacity whether they are cycled or not.

The main responsible for the degradation of a lithium-ion battery is the SEI (Solid Electrolyte Interface). We could summarize the degradation process as follows:

1. The anode graphite operates at voltages outside the electrochemical stability range of the electrolyte components and is therefore electrochemically unstable.
2. During the first charge, a metastable passivation film forms on the SEI anode surface. Irreversible consumption of Li and electrolyte occurs.
3. During the first cycles the SEI is formed, but during cycling it grows and stabilizes.
4. During the charging and discharging of the battery, the graphite volume changes, causing the SEI to break.
5.Due to this rupture, the graphite comes into contact again with the electrolyte, forming the SEI and consuming more lithium.

✅ This continuous formation, thickening and rupture of the SEI causes a continuous decrease in capacity and increases the internal resistance of the battery.

𝗣𝗲𝗿𝗼 ¿𝗰ó𝗺𝗼 𝗶𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝗻𝗲 𝗹𝗮 𝘁𝗲𝗺𝗽𝗲𝗿𝗮𝘁𝘂𝗿𝗮 𝗲𝗻 𝘁𝗼𝗱𝗼 𝘁𝗼𝗱𝗼 𝗲𝘀𝘁𝗲 𝗽𝗿𝗼𝗰𝗲𝘀𝗼 𝗽𝗿𝗼𝗰𝗲𝘀𝗼? Arrhenius has the answer.

The Arrhenius equation is a mathematical formula that describes how the rate of a chemical reaction depends on temperature. The higher the temperature, the higher the reaction rate.

✅ The negative impact of elevated temperatures on behavior is mainly attributed to an increased rate of SEI degradation, as, the SEI film begins to degrade or dissolve.

The reaction rate increases because the fraction of molecules that exceed the activation energy is higher.

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Industrial Project Manager DSP Solar