Side reactions in a battery cell refer to unintended chemical or electrochemical reactions that occur alongside the main charge/discharge processes. These reactions do not contribute to energy storage but can lead to performance degradation, capacity loss, increased internal resistance, and safety issues.
Common types of side reactions include:
Electrolyte decomposition: At high or low voltages, electrolyte components break down, forming gases or unwanted byproducts.
Solid Electrolyte Interphase (SEI) formation: While a stable SEI layer is essential (especially on the anode), continuous growth consumes lithium and leads to capacity fade.
Lithium plating: During fast charging or low-temperature operation, lithium can deposit on the anode surface as metal, reducing battery capacity and posing safety risks.
