Charging lithium-ion cells at different rates boosts EV battery pack life, per Stanford study
Stanford University researchers have found a way to make lithium-ion battery packs last longer and suffer less deterioration from fast charging.
In “Extending Life of Lithium-Ion Battery Systems by Embracing Heterogeneities via an Optimal Control-Based Active Balancing Strategy,” published in IEEE Xplore, the researchers explain how actively managing the amount of current flowing to each cell in a pack, rather than delivering charge to all cells uniformly, can minimize degradation.
The research team started by creating a high-fidelity computer model of battery behavior that represents the physical and chemical changes that occur inside a battery during its operational life.
“If not properly tackled, cell-to-cell heterogeneities can compromise the longevity, health and safety of a battery pack and induce an early malfunction,” said senior study author Simona Onori. “Our approach equalizes the energy in each cell in the pack, bringing all cells to the final targeted state of charge in a balanced manner and improving the longevity of the pack.”
Initial simulations suggest that batteries using the new technology could handle at least 20% more charge-discharge cycles, Onori said—even with frequent fast charging, which puts extra strain on the battery.