Coming soon: a smartphone with a four-day battery life

Thanks to the smartphone's status as the Swiss army knife of the average consumer's digital life, battery life is fast becoming the number one feature that people look for when choosing a handset.

Unfortunately, battery technology isn't moving at the same pace as every other component in the latest generation of smartphones, meaning that, if anything, battery life is becoming comparatively shorter.

However, that might not be true for long. Researchers at the University of Stanford believe they have essentially created a new type of battery that could offer three times the life of today's smartphone and tablet cells and have published their findings in the latest edition of science journal Nature.

At the moment the only way to double or triple a handset's battery life while on the go is to invest in a case with an integrated second battery or to carry a standalone battery pack that can be plugged into the phone to top up the power when the battery's about to die.

Of course, as battery life is a hot topic, similar reports about breakthroughs make the headlines on a regular basis, but what makes this discovery, by the team headed up by Yi Cui, a professor of Material Science and Engineering, exciting is that it may have solved a problem that was at the core of existing lithium ion batteries.

If lithium could be used in both the electrolyte and anode of a cell, efficiency would be significantly boosted. However, until now, doing so would create a highly volatile and unstable battery. Lithium expands in an uneven and unpredictable manner and can twist and deform a battery, cause overheating, short circuiting and for the battery to crack and seep its charge. That's why the anode of a battery is made from silicon or graphite, which have predictable behavior.

However, the team has found a way of using lithium in both ends of the cell by fencing in the anode with a honeycomb layer of carbon nanospheres.

And while the new battery requires further testing, if it can be proved to be stable and can be easily mass produced, then the next generation of smartphones, tablets and even electric cars could boast between 100 percent and 200 percent greater battery life between charges.

As Steven Chu, the former US Secretary of Energy and Nobel Laureate who was also part of Yi Cui's team, told Physics.org: "In practical terms, if we can improve the capacity of batteries to, say, four times today's, that would be exciting. You might be able to have cell phone with double or triple the battery life or an electric car with a range of 300 miles that cost only $25,000 -- competitive with an internal combustion engine getting 40 mpg."