Lithium-ion battery degradation over time significantly impacts their storage capacity, leading to reduced energy storage and delivery capabilities. Here are the key factors involved in this degradation process:
Factors Affecting Degradation
1. Cyclic Degradation
- Charge/Discharge Cycles: Lithium-ion batteries have a limited number of cycles before their capacity diminishes. Generally, they degrade to about 80% of their full capacity after between 500 and 2,000 cycles.
- Depth of Discharge: The deeper the discharge, the more stress on the battery, which accelerates degradation.
2. Calendar Aging
- Temperature and State of Charge: Even when not used, batteries degrade due to internal chemical reactions. Higher temperatures and full charge states accelerate this process.
- Examples: Storing batteries at 40°C can reduce capacity to 65% after one year if fully charged, compared to 85% at 40% charge.
3. Increased Internal Resistance
As batteries age, internal resistance increases. This results in slower charging and discharging rates and more heat generation during use, further accelerating degradation.
Impact on Storage Capacity
1. Capacity Fade
- Reduced Energy Storage: Degradation leads to a decrease in the battery’s ability to store energy, resulting in fewer hours of device operation or shorter driving ranges in electric vehicles.
2. Operational Impact
Reduced capacity means devices may need more frequent recharging or may not perform as effectively, leading to decreased efficiency and effectiveness of the battery over time.
Preventing or Slowing Degradation
1. Optimal Charging Practices
- Avoid extreme high and low states of charge. Partial charging (e.g., maintaining between 40% and 80% charge) can help reduce degradation.
- Avoid overcharging; keep below 4.10V/cell for most Li-ion batteries.
2. Temperature Control
Store batteries in cooler environments when not in use to slow degradation.
By understanding these factors, users can adopt strategies to extend the life of their lithium-ion batteries and maintain their storage capacity.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-degradation-of-lithium-ion-batteries-over-time-affect-their-storage-capacity/
