While clear screens, faster processors and millions of apps are the selling points of mobile technology, the battery keeping your gadget alive doesn’t get much attention.
The reason is because the essential electrochemical process inside a battery hasn’t changed much in the past two centuries.
The act of transferring a current repeatedly through the electrodes as a battery charges and discharges degrades the electrodes and shorten the battery’s life.
So a University of Southern California team is looking for better electrodes. They’re experimenting with silicon nanoparticles to help the current move more smoothly through electrodes. Nanoscale ‘wires’ that transfer current faster promise a full charge in 10 minutes and up to three times as much energy. “It opens the door for the design of the next generation lithium-ion batteries,” said USC professor Chongwu Zhou.
While the lithium that makes up the standard of current battery technology is expensive and heavy, sodium (a related element on the periodic table) is found everywhere from table salt to seawater. Michigan Technological University associate professor Reza Shahbazian-Yassar is using an electron telescope to better figure out the chemistry involved in a flat battery to build a better model using the much more plentiful material.
“With better understanding on why batteries become dead, we hope to help battery developers,” Professor Shahbazian-Yassar said. “We’re studying fundamental reactions to find out what materials and electrodes will do a better job hosting the sodium. After all, who doesn’t want an iPad or iPhone that lasts a month?”
Sodium isn’t the only material being investigated. Zinc-air batteries were theorised in the 1930s and used by the US military in the 1960s. But research into lithium-air might mean instead of a heavy, enclosed battery in your device, the electrodes gather electrons from oxygen outside to produce the current.
Early tests from engineering and chemistry departments in Seoul and Rome think have been extremely encouraging, with no real difference in performance between the 20th and 100th charge cycle. The study’s authors are particularly interested in the electric car market, saying ‘owing to its exceptionally high energy potentiality, the lithium–air battery is a very appealing candidate for fulfilling this role.’
But with a whopping 13,500Wh/kg – up to 10 times the capacity of today’s lithium batteries – imagine what it could do for your handset?
The other solution being looked at is simply cramming more lithium ions into the battery cell and moving them around faster, which generates the electricity and means a longer charge and faster recharge.
Northwestern University electrochemistry professor Dr Harold Kung is working with nano-scale holes through the battery medium that could let the electrochemical molecules move more freely, and he’s making progress.
But as he says, most researchers are working with a single bit of what has to work in a much bigger system. “Our long-term tests were conducted for the individual component only. We need to get reliable test results in full battery configuration and usage conditions, which takes time.”