The energy storage capacity can exhibit gradual linear deterioration over time, but often demonstrates abrupt nonlinear decreases when taken to stressful extremes of temperature, discharge rate, depth of discharge, or dynamic mechanical loads. The exact capacity fall-off depends heavily on battery chemistry and construction. The following are the factors that affect the variations of the energy storage capacity:
- Charge/Discharge Rate: Faster charge and discharge cycles tend to decrease the usable capacity of a battery. This is because there are kinetic and transport limitations in the battery that prevent full utilization of capacity at high rates. Slow rates allow more complete charging/discharging.
- Depth of Discharge: Discharging a battery to a greater depth of discharge on each cycle can accelerate the loss of active materials, gradually decreasing total capacity over time. Shallower discharges are less damaging to longevity.
- Temperature: Increasing/decreasing battery temperature speeds up degradation mechanisms. Temperature extremes also limit kinetic processes, decreasing instantaneous capacity. Moderate temperatures optimize capacity.
- Load Profile: Dynamic load conditions with frequent, rapid charge/discharge pulses can impose mechanical and thermal stresses that accelerate long-term capacity fade. Steadier loads preserve capacity better.
If you want to maximize the instantaneous usable capacity as well as the long-term lifetime capacity of the batteries, you need to optimize the factors above.
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What strategies are commonly employed to Battery SOP optimization in energy storage systems?
