The charging efficiency and method significantly affect the lifespan of lithium-ion batteries due to the stresses induced by charging conditions on the battery cells.
Impact of Charging Voltage on Lifespan
- Lithium-ion batteries are typically charged to a peak voltage of about 4.20 V per cell, which provides a typical cycle life of 300–500 cycles.
- Reducing the peak charge voltage prolongs the battery life substantially. For example, charging to 4.10 V/cell can extend the life to 600–1,000 cycles, 4.00 V/cell to 1,200–2,000 cycles, and about 3.90 V/cell can provide 2,400–4,000 cycles.
- The optimal charge voltage for balancing longevity and capacity is around 3.92 V per cell, which minimizes voltage-related stress on the battery and helps avoid premature aging.
However, lowering the charge voltage reduces the battery’s capacity by roughly 10% for every 70 mV decrease, meaning there’s a trade-off between capacity and lifespan.
Effect of Charging Current and Initial Charge
- Charging lithium-ion batteries at unusually high currents immediately before leaving the factory (the first charge) can increase their lifespan by about 50% and reduce the initial charging time dramatically (from about 10 hours to 20 minutes).
- This fast, high-current initial charge induces favorable changes to the battery electrodes that improve performance and cycling durability.
General Charging Efficiency Considerations
- Charging efficiency also relates to how much of the input electrical energy actually converts into stored chemical energy without causing heat or stress damage.
- Inefficient or improper charging (such as overcharging, charging at high temperature, or frequent deep discharges) accelerates degradation by increasing stress and heat within the cells.
- Maintaining mid-state-of-charge cycling and avoiding extreme charge states and high heat prolong battery life.
Summary
- Charging voltage management is critical: lower peak voltages extend lifespan at the cost of usable capacity.
- The initial fast, high-current charge can significantly boost longevity.
- Efficient and controlled charging reduces cell stress, heat buildup, and degradation, thereby enhancing cycle life.
- Overall, optimizing charging strategies to balance voltage, current, and temperature conditions maximizes lithium-ion battery lifespan.
This relationship means battery users and manufacturers should carefully consider charging protocols to extend battery life effectively while managing performance trade-offs.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-charging-efficiency-of-lithium-ion-batteries-affect-their-lifespan/
