The researchers have created a new electrode for lithium-ion batteries that provides the energy boost. Specifically, they combined two chemical engineering approaches to handle the challenges of energy capacity and charge rate. The research is detailed in a new paper published by the journal Advanced Energy Materials.
"We have found a way to extend a new lithium-ion battery’s charge life by 10 times," Harold Kung, a professor of chemical and biological engineering and a lead author of the paper, said in a statement. "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."
Lithium-ion batteries charge through a chemical reaction in which lithium ions are sent between two ends of the battery, the anode and the cathode. Currently, the performance of lithium-ion batteries is limited by both the charge density–or how many lithium ions can be packed into the anode or cathode–as well as the speed at which the lithium ions can make their way from the electrolyte into the anode. These affect both the amount of energy the battery can hold and how long it takes to charge.
However, the researchers attacked the problem by doing two things. They increased the number of lithium-ion atoms in the battery’s electrode by using silicon in place of carbon between sheets of carbon-based graphene in the battery, which makes the battery much more efficient. They also poked microscopic holes in the graphene sheets in the anode, which allows the lithium ions to travel faster within the battery, reducing charging time.