New Tech Promises Longer Battery Life for All
Tired of your new iPhone 4S running out of power before Siri had the chance to answer your question? Your battery problems may soon be a thing of the past as researchers have developed a way for batteries to hold 10 times the charge than current technology.
Researchers at Northwestern University have developed a new lithium-ion electrode that will boost the charge of conventional batteries and allow them to recharge 10 times faster.
"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 the paper, in a statement released by the university. "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."
The researchers achieved this super battery by using sheets of silicon with graphene sheets. Normally, current lithium-ion batteries are charged by electrons moving from the electrolyte into anodes. Batteries today use anodes made from graphene which only allow one lithium atom per one six carbon atoms. By changing the material of the anode into silicon more lithium atoms can move into the anode. However, silicon contracts and expands during charging which can cause the battery to suffer fragmentation.
Kung's team at Northwestern was able to solve this fragmentation problem by alternating clusters of silicon between graphene sheets. This amalgamation of silicon and graphene can hold more lithium ions than traditional batteries squeezing more power from the battery. The team also drilled 10 to 20 nanometer wide holes in the sheets to speed up the recharging time. The drilled holes helps lithium ions move faster and cut recharging time by a factor of 10. A battery using the new material from Northwestern can charge fully in 15 minutes and last a week before needing a recharge.
"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.
The only problem with the technique is that the recharging and power gains fall after 150 charges. The team is now looking to further improve the technique and is researching improvements to the cathode, where the current flows out.