Another Reason Why Batteries Can’t Charge in Minutes

upstart writes:

Another reason why batteries can't charge in minutes:

Lithium-ion batteries contain both a positively charged cathode and a negatively charged anode, which are separated by a material called an electrolyte that moves lithium ions between them. The anode in these batteries is typically made out of graphite -- the same material found in many pencils. In lithium-ion batteries, however, the graphite is assembled out of small particles. Inside these particles, the lithium ions can insert themselves in a process called intercalation. When intercalation happens properly, the battery can successfully charge and discharge.

When a battery is charged too quickly, however, intercalation becomes a trickier business. Instead of smoothly getting into the graphite, the lithium ions tend to aggregate on top of the anode's surface, resulting in a "plating" effect that can cause terminal damage -- no pun intended -- to a battery.

"Plating is one of the main causes of impaired battery performance during fast charging," said Argonne battery scientist Daniel Abraham, an author of the study. "As we charged the battery quickly, we found that in addition to the plating on the anode surface there was a build up of reaction products inside the electrode pores." As a result, the anode itself undergoes some degree of irreversible expansion, impairing battery performance.

Read more of this story at SoylentNews.