Electric car batteries age as they are charged. Researchers hope that this effect could be greatly reduced if the charging current is pulsed correctly.
The durability of lithium-ion batteries could be significantly increased using pulsed charging current. In the best case, the duration of the battery life doubles compared to charging with constant current, as a study led by the Helmholtz Center and the Humboldt University in Berlin has shown. The researchers have used conventional batteries both with a constant current flow and with charged with pulsed current and then dismantled and examined. The pulse current batteries showed significantly fewer negative effects on the electrodes, for example in the form of cracks or deposits. “Charging with pulsed current promotes the homogeneous distribution of lithium ions in the graphite. This reduces the mechanical stress and thus the formation of cracks in the graphite particles, so that the graphite anode remains stable for longer,” say the researchers. The so-called pulse current is nothing other than direct current that is pulsed (or chopped). So there is always a rhythm of power on and power off. Currently, electric car batteries are usually charged with constant current. To switch to pulsed charging, only the charging protocols would have to be adapted, but not the infrastructure and battery technology. According to the researchers, however, the correct pulse frequency is crucial for delaying the aging effect.
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