Current state of Battery Technology
Perhaps the greatest design obstacle for today’s portable devices is to find a source of power that is small, light-weight, long-lasting, durable, and -- of course -- powerful. Whether the product is a cell phone, an electric car, a We-Vibe, a pacemaker, or any of the scores of devices to which we’ve become accustomed to charging on a regular basis, providing the power required is a challenge. Moreover, in the design of intelligent personal devices, the task of making the battery unnoticeable to the wearer is often the difference between a product that will attract the consumer versus one that won’t.
So many of our powered devices have imposed a routine on our lives rather than conforming to our needs, usually because they require a long charge time and return a relatively short power cycle. But what if your phone could be charged up to 70% in just two minutes? The demand to charge it (or even your electric car) over-night would disappear, as would the need to plan your life around your accessories.
Today’s lithium ion batteries
In conventional lithium-ion batteries, the efficiency is largely determined by the surface area of the graphite anode (or negative terminal) which reacts with the acid within the battery. During use, this reaction produces a current; conversely, while charging, the reaction draws a current. These reactions are not perfect however so over time the battery loses a significant portion of its capacity, typically in just 500 charge cycles. The production of heat is another obstacle because as a battery’s temperature increases, the efficiency and lifespan decrease.
Two universities are making notable advances in the area of battery technology, the Massachusetts Institute of Technology (MIT) and Nanyang Technological University (NTU), each in a slightly different way.
MIT researcher Gerbrand Ceder has discovered that one of the limiting factors in battery charge-time is the ability of the lithium ions to flow through the miniature holes on the surface of the anode. Unless the ions were directly in front of these holes, they cannot get through, so by engineering the material to create a so-called “beltway,” the rate of charging could be reduced to 1/18th of the time required by traditional lithium-ion batteries. To overcome the issue of excessive heating, changing from the common lithium-cobalt mixture to lithium iron phosphate has provided the solution. The latter does not suffer the heating issues that we encounter with batteries found in typical laptops, for example.
Alternatively, researches at NTU have developed a technique that creates nano-tubes made of titanium dioxide, an abundant industrial material, which greatly increases the efficiency of the chemical reactions. Similar to the advances at MIT, this new structure allows the battery to be charged to 70% within two minutes and greatly reduces the heating of the battery. Furthermore, the battery degrades much more slowly, lasting potentially two decades before needing replacement.
With the means to quickly charge batteries, the devices we use will no longer need to hold as much charge at once, allowing for them to be reduced drastically in size, thus enabling more comfortable devices to be worn, or car batteries to be rapidly rejuvenated. Still, there are still the issues to be overcome, such as total charge, but for designers, this inexpensive new technology marks a leap forward in mobile power.