A team of Northwestern University engineers has created a new type of electrode for lithium-ion batteries — the kind regularly used to power cellphones and other mobile devices — that allows the batteries to hold a charge up to 10 times greater and which can also be charged 10 times faster than current batteries.

“We have found a way to extend a new lithium-ion battery’s charge life by 10 times,” said Harold H. Kung, lead author of a paper describing the research, originally published by the journal Advanced Energy Materials. The team’s work was described in a Northwestern University news article and reported by Government Computer News.

“Even after 150 charges, which would be one year or more of operation, the battery is still five times more effective than lithium-ion batteries on the market today,” said Kung.

Kung, a professor of chemical and biological engineering in the McCormick School of Engineering and Applied Science, explained that with current technology, the performance of a lithium-ion battery is limited in two ways.

Its energy capacity is limited by how many lithium ions can be packed into the battery’s the anode, where energy flows into the battery, or the cathode, where electrical current flows from the battery. The battery’s charge rate, meanwhile, depends on how quickly lithium ions can travel through the battery’s electrolyte soup to the anode.

As Northwestern University’s article described it:

In current rechargeable batteries, the anode — made of layer upon layer of carbon-based graphene sheets — can only accommodate one lithium atom for every six carbon atoms. To increase energy capacity, scientists have previously experimented with replacing the carbon with silicon, as silicon can accommodate much more lithium: four lithium atoms for every silicon atom. However, silicon expands and contracts dramatically in the charging process, causing fragmentation and losing its charge capacity rapidly.

Currently, the speed of a battery’s charge rate is hindered by the shape of the graphene sheets: they are extremely thin — just one carbon atom thick — but by comparison, very long. During the charging process, a lithium ion must travel all the way to the outer edges of the graphene sheet before entering and coming to rest between the sheets. And because it takes so long for lithium to travel to the middle of the graphene sheet, a sort of ionic traffic jam occurs around the edges of the material.

Kung’s research team has found a way to increase the number of lithium atoms in the anode, and speed their movement through the electrolyte, by using a new combination of sandwiched clusters of silicon between graphene sheets.

The technology could become available in the marketplace within the next three to five years, according to the engineers.