![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
The real interest here is battery electric and hybrid vehicles as those batteries are huge and expensive, but it would also be cool if you could double the service life of your smart phone or tablet battery!
The issue is pretty simple. We've always charged batteries using Constant Current (CC), where we apply a constant voltage and current to the batteries until they charge. We do it because we've always done it that way, and it's really, really easy from an electronics standpoint. I could sketch you a basic rectifying circuit to convert AC to DC at any given time, and that is what a charger does. The problem is, it increases the thickness of the anode of the Li-Ion battery, which decreases the battery's life.
Enter Pulse Charging (PC). With Pulse Charging, you're needing a more intelligent charging apparatus (okay, doable) that is introducing brief bursts (pulses) of electricity into the battery. This does not lead to anode thickening over time, and subsequent study of the test batteries shows that they can nearly double the life of the battery while retaining 80% of its capacity!
From the article: "The batteries were either charged conventionally with constant current (CC) or with a new charging protocol with pulsed current (PC). Post-mortem analyses revealed clear differences after several charging cycles: In the CC samples, the solid electrolyte interface (SEI) at the anode was significantly thicker, which impaired the capacity.
The team also found more cracks in the structure of the NMC532 and graphite electrodes, which also contributed to the loss of capacity.
In contrast, PC-charging led to a thinner SEI interface and fewer structural changes in the electrode materials."
and...
"The pulsed current charging promotes the homogeneous distribution of the lithium ions in the graphite and thus reduces the mechanical stress and cracking of the graphite particles. This improves the structural stability of the graphite anode," he concludes.
The pulsed charging also suppresses the structural changes of NMC532 cathode materials with less Ni-O bond length variation.
...
However, the frequency of the pulsed current counts: High-frequency PC charging protocols with square-wave current extend the service life of commercial LIBs the most, with a doubled cycle life (with 80% capacity retention) achieved in this study. Co-author Prof. Dr Julia Kowal, an expert in electrical energy storage technology at TU Berlin, emphasises: "Pulsed charging could bring many advantages in terms of the stability of the electrode materials and the interfaces and significantly extend the service life of batteries."
Very cool stuff. And since this is charging methodology, you're not changing the battery technology - though that's improving at a fairly rapid pace - so this should be implemented fairly easily. For certain values of the word easily.
There were a couple of things in the article that I didn't see that I'd like more information on. They didn't talk about any difference in heat of the test batteries during the charging cycles of the two methodologies, nor did they talk about any difference in the charging times. Both of those have some importance in a variety of applications.
It will be very interesting to see how this develops into field-deployed tech.
https://www.sciencedaily.com/releases/2024/04/240409123909.htm
https://hardware.slashdot.org/story/24/04/14/020205/could-a-new-charge-double-the-service-life-of-li-ion-batteries
The issue is pretty simple. We've always charged batteries using Constant Current (CC), where we apply a constant voltage and current to the batteries until they charge. We do it because we've always done it that way, and it's really, really easy from an electronics standpoint. I could sketch you a basic rectifying circuit to convert AC to DC at any given time, and that is what a charger does. The problem is, it increases the thickness of the anode of the Li-Ion battery, which decreases the battery's life.
Enter Pulse Charging (PC). With Pulse Charging, you're needing a more intelligent charging apparatus (okay, doable) that is introducing brief bursts (pulses) of electricity into the battery. This does not lead to anode thickening over time, and subsequent study of the test batteries shows that they can nearly double the life of the battery while retaining 80% of its capacity!
From the article: "The batteries were either charged conventionally with constant current (CC) or with a new charging protocol with pulsed current (PC). Post-mortem analyses revealed clear differences after several charging cycles: In the CC samples, the solid electrolyte interface (SEI) at the anode was significantly thicker, which impaired the capacity.
The team also found more cracks in the structure of the NMC532 and graphite electrodes, which also contributed to the loss of capacity.
In contrast, PC-charging led to a thinner SEI interface and fewer structural changes in the electrode materials."
and...
"The pulsed current charging promotes the homogeneous distribution of the lithium ions in the graphite and thus reduces the mechanical stress and cracking of the graphite particles. This improves the structural stability of the graphite anode," he concludes.
The pulsed charging also suppresses the structural changes of NMC532 cathode materials with less Ni-O bond length variation.
...
However, the frequency of the pulsed current counts: High-frequency PC charging protocols with square-wave current extend the service life of commercial LIBs the most, with a doubled cycle life (with 80% capacity retention) achieved in this study. Co-author Prof. Dr Julia Kowal, an expert in electrical energy storage technology at TU Berlin, emphasises: "Pulsed charging could bring many advantages in terms of the stability of the electrode materials and the interfaces and significantly extend the service life of batteries."
Very cool stuff. And since this is charging methodology, you're not changing the battery technology - though that's improving at a fairly rapid pace - so this should be implemented fairly easily. For certain values of the word easily.
There were a couple of things in the article that I didn't see that I'd like more information on. They didn't talk about any difference in heat of the test batteries during the charging cycles of the two methodologies, nor did they talk about any difference in the charging times. Both of those have some importance in a variety of applications.
It will be very interesting to see how this develops into field-deployed tech.
https://www.sciencedaily.com/releases/2024/04/240409123909.htm
https://hardware.slashdot.org/story/24/04/14/020205/could-a-new-charge-double-the-service-life-of-li-ion-batteries
