Jared Newman / TIME.com
Pushing Lithium-Ion’s Limits
Virtually every smartphone today relies on lithium-ion batteries, which provide power by transferring electrons between the anode and cathode of a battery cell. The amount of lithium ions inside the battery directly affects how long your phone can last on a charge.
The problem lies in the graphite that stores lithium ions in the anode of a battery. Graphite has a theoretical limit to how much lithium it can hold, and today’s batteries have pretty much reached it. While bigger batteries are always an option–as seen in Motorola’s Droid Razr Maxx–most people don’t want thicker, heavier phones, so phone makers sacrifice battery life in the name of slenderness.
With graphite-based anodes reaching peak capacity, the race is on to replace graphite with silicon, a material that can offer ten times the capacity of today’s batteries–at least in theory.
“There’s a lot of research going on, because silicon is the best material for absorbing lithium, and it has the highest potential capacity of any material now,” said Phillip Roberts, CEO of California Lithium Battery.
Swapping silicon for graphite isn’t easy. Silicon swells while charging, causing electrical contacts to break during discharge, and ultimately degrading the battery. That’s a dealbreaker for smartphones, which need to survive through at least a couple of years’ worth of daily recharging.
California Lithium Battery is working on a composite of silicon and graphene–a Nobel prize-winning material made from atom-thick layers of graphite–that combines the capacity of the former with the stability of the latter. And unlike some other silicon-based anode solutions, this composite, which is licensed from Argonne National Laboratory, prevents the agglomeration of silicon that leads to swelling and reduced cycle life, Roberts said.
Roberts hopes that within six months, the company can produce material by the metric ton and send it out to battery makers and phone makers for testing. In two years, the company expects its silicon-based anode to replace the graphite-based anodes in existing batteries, bringing a 30 percent improvement in capacity.
“I would say within two years, you’re going to see that technology. It’s happening relatively quickly. Behind the scenes, there’s a lot going on,” Roberts said.
When paired with other advances in cathode and electrolyte materials, he expects capacity to improve by 100 percent, possibly within three years.
The Tech World Is Watching
Companies working on silicon anode technology have also felt the pressure from battery and device makers. California Lithium Battery was attracting so much attention that it changed its initial focus from electric cars to consumer electronics. CEO Phillip Roberts said “pretty much every smartphone maker” has shown interest in the company’s technology. “We haven’t contacted one company ourselves,” CEO Phillip Roberts said. “Every group so far that we’re working with contacted us.”
You have to wonder, though, how phone makers will use new battery technology once it’s available. Will they finally deliver the rock-solid, 24-hour batteries that we need, or will they push for ever-thinner devices that are just nice to look at? It seems we have a least a couple years to agonize over the answer.