New technology could double the life of lithium batteries

Rechargeable batteries are extremely important for everything from cell phones to electric cars and solar cell batteries. Development of new battery technologies is slow, and current batteries are not much better than they were 15 years ago. Therefore, the progress made by a group of researchers at four universities in Aalborg and Berlin is now presented in a report in the scientific journal Advanced energy materials amazing.

Researchers have previously investigated the chemical processes that lead to degraded lithium batteries with less and less capacity the more they are used. In the new report, they tested a new method for charging batteries that reduces wear and extends lifespan by up to two times.

Today, batteries are charged with a fixed voltage and current that is adjusted while charging the battery. For example, fast charging on modern cell phones can charge the first 50 percent at 25 watts, after which the power gradually decreases until it reaches perhaps 5 watts for the last 10 percent.

The researchers' new technique instead involves charging the battery in short pulses, which means that the battery's resistance does not increase as quickly as with conventional charging, that the anode does not grow as quickly by building up a lithium coating, and that the cathode does not grow. They wear out as quickly as possible. In short, the battery retains more of its original chemical structure for longer.

The new charging algorithm could be used with existing batteries, but since the charging circuitry that controls charging is in the products and not in external chargers, it is not certain that any products existing today will be able to benefit from the breakthrough if and when it begins to be put into practical use.