The devices we carry around tend to evolve much quicker than energy sources inside them. If you need proof of that, just look at the ubiquitous lithium ion battery, which has seen little improvement for over a decade. That may all change within the next few years with advances researchers at MIT have made with photonic crystals — optical nanostructures that impact the flow of photons. By taking advantage of metals like tungsten and tantalum, the group at MIT has crafted infrared-absorbing photonic crystals that can operate at temperatures up to 1200 degrees Celsius. That type of heat results in radiation that can be converted to electricity, providing energy for what potentially could be a wide array of use cases. MIT's research has been eyed by NASA as a superior method of providing power to rovers destined for deep-space travel. Traditionally it has relied upon solar energy, meaning that missions need to be paused (often for lengthy periods) when sufficient light is unavailable.

Of course, another big draw is implementation with portable electronics. For instance, replacing batteries with thermophotovoltaic generators — which transform fuel-generated heat into electricity — could extend longevity tenfold, depending on a device's size. Other areas where MIT's work could make an impact include solar / thermal conversion, hydrocarbon generators, and power plant waste removal. As crazy as it sounds, having nuclear-based energy in your pocket might not be far off. The MIT researches believe the technology could be viable for widespread use in as little as two years, though they disclaim five is more likely. Will this be the tech that finally puts lithium ion out to pasture?