Slaves of electricity

We are slaves of electricity. Outwardly, it might appear that Tesla and Edison wrangled electricity into submission -- into usable power -- but really, ever since the first commercial light bulb and high-fidelity telegraph, electricity has ruled the lives of men.

Almost every facet of contemporary society is dictated by the properties of electricity. Like fresh water, sanitation, and education, access to electrical power can make or break a community.

The tenacity of electric-powered devices and machines is unbelievably vast. With modern robotics, there is almost nothing that electricity can't do -- and a lot that electricity can do that humans can't. The amount of work performed by electricity is beyond belief, too. From sowing crops to preparing food, from making computer chips to manufacturing cars, electricity does so much work that would otherwise have to be done by humans.

Which brings me neatly onto the topic of batteries. At their most basic, batteries are devices that store electrical power. Until very recently, the archetypal battery would be an alkaline AA -- useful for listening to music on your Walkman, or powering your RC car controller; batteries were useful, but hardly vital. Over the last few years, though, a dramatic shift has occurred. As chip makers -- such as Intel, AMD, and Qualcomm -- have refined their processes, computers have become steadily more mobile: Laptops, then mobile phones, then netbooks, and finally smartphones and tablets. This year, in the US, 76% of all PCs sold will be laptops, and tablets will outsell desktops. In the next couple of years, it is predicted that 75% of Americans will own a smartphone.

In short, the vast majority of computer users now rely on battery-powered devices -- which is a problem, because battery technology isn't developing at a pace that can keep up with our usage. While we're almost at the stage where silicon chips are assembled atom by atom, battery technology has remained virtually unchanged since Alessandro Volta created the first battery in 1800: Two electrodes with an electrolyte between them. While semiconductor complexity (processors and LCD displays) has generally doubled every 18 months in accordance with Moore's law, battery capacity has slowly clawed its way upwards. Even more worryingly, theoretically there is no better electrode than lithium when it comes to electrochemical potential or energy-to-weight ratio -- lithium-based batteries are as good as it gets.

Mobile LTE is another fine example: It might be faster than UMTS 3G, but it consumes a lot more power in the process. First-generation LTE devices, such as the HTC Thunderbolt, famously ran out of juice after just a few hours of LTE connectivity. Ditto RAM and non-volatile storage: As capacities and transfer speeds increase, as does power consumption. The fact of the matter is that high-res screens and wireless communications (WiFi, cellular) consume the lion's share of your battery's capacity -- and, unless we all come to an agreement that high-PPI displays and mobile internet access are pointless, this won't change.

While the next few years will likely be full of beautiful, powerful devices that only last a few hours between charges, there is some light at the end of the tunnel. Intel, AMD, and ARM licensees are all frantically battling to produce the most efficient chips for mobile devices. Sharp's IGZO and Samsung's LTPS promise to significantly reduce the display's power consumption. With the recent shift to 28 and 22nm processes, wireless radios consume less power. At the end of the day, though, we're talking about reductions of 10 or 20% over a few years, which is unlikely to be enough to offset the unstoppable double whammy of Moore's law and society's shift towards mobile, ubiquitous computing.

Ultimately, our biggest hope lies in battery technology itself. One of the biggest jumps in battery capacity will come from replacing graphite anodes (the positive electrode) with silicon nanotubes. The same group (Yi Cui and his team at Stanford University) is working on an everlasting battery that uses water as an electrolyte -- but that battery is angled towards power grid storage (another equally huge topic, especially with the growth of solar power). Also on another tack, IBM is working on a lithium-air battery that's a tenth of the size/weight of conventional li-ion batteries -- it will be primarily targeted at electric cars, but could eventually (10+ years) be used to power mobile devices.