Lithium-ion batteries can handle frequent power outages, but repeated cycles of partial discharge and recharge inherent to outages do contribute to their degradation over time. The extent of degradation depends on factors such as the depth of discharge, state of charge, temperature, and battery chemistry.
Factors Affecting Degradation in Frequent Power Outages
- Cycle Depth and State of Charge: Lithium-ion batteries degrade faster when deeply discharged repeatedly. Shallow discharges (low Depth-of-Discharge or DoD) extend battery life, while cycling over low state-of-charge ranges, especially under high temperature, accelerates capacity loss—particularly for batteries with silicon-graphite composite electrodes that suffer from faster degradation due to silicon expansion on lithiation.
- Temperature: Higher operating temperatures exacerbate degradation. Cycling at elevated temperatures (e.g., 40°C) significantly increases capacity loss due to accelerated breakdown processes within the electrodes.
- Self-Discharge and Internal Reactions: Lithium-ion batteries also degrade due to self-discharge and chemical side reactions, which lower voltage and capacity over time even if the battery is not in use. Improvements in electrolyte additives and electrode coatings are being developed to reduce self-discharge and thus extend life.
- Charge Voltage: Charging to lower peak voltages than the typical 4.2V per cell can substantially prolong cycle life at the expense of usable capacity. For example, reducing peak voltage to 4.1V or 4.0V can roughly double or quadruple cycle life, aiding longevity in systems exposed to frequent cycling.
Summary
- Frequent power outages cause the battery to cycle more often, which increases degradation due to cycling wear.
- Minimizing deep discharges and avoiding high temperature operation during outages helps mitigate damage.
- Battery designs that limit silicon use or manage state-of-charge more carefully can last longer under such conditions.
- Optimizing charge voltage and controlling battery temperature during outage recovery cycles can further extend lifespan.
- Overall, lithium-ion batteries can tolerate frequent outages but will degrade faster than under stable, controlled usage conditions, necessitating strategic management to maximize longevity.
In conclusion, lithium-ion batteries can handle frequent power outages but experience accelerated degradation from the associated cycling and environmental stresses. Proper management of charge levels, temperature, and depth-of-discharge can meaningfully reduce this degradation and extend battery life.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/can-lithium-ion-batteries-handle-frequent-power-outages-without-degrading/
