Despite high costs and limited life, Li-Ion batteries are the preferred choice for years to power portable computers, mobile phones and almost any other portable gadgets.
Currently, progress in the world of lithium batteries has paused, showing that Li-Ion battery technology begins to reach its limits. A good example of this is the growing gap between energy demand asked to power tablets or mobiles and energy storage capacity demonstrated by current batteries. Despite all efforts, the increase of energy density in Li-ion batteries is done in small steps at the price of escalating production costs.
A possible alternative comes from a group of researchers from the University of Tokyo, who propose the replacement of lithium in the composition of batteries with a combination of less expensive materials, but with results at least as good.
The new batteries are based on electrodes formed from a mixture of iron oxide, manganese and sodium, the latter being a reactive metal with properties very close to lithium, but more abundant in nature and therefore much cheaper to use.
Na-ion battery developed by the team led by Shinichi Komaba offers an energy density of 520 mWhr / g, similar to a Li-Ion. Unfortunately, in their current form Na-ion batteries developed by Japanese researchers lose their energy storage capacity after only 30 cycles charge / discharge, so that their use in commercial products is not yet possible.
Although Japanese researchers delayed for some time, trying to improve battery longevity, the saving solution could come from Argonne National Laboratory in Chicago, where they are testing another version of the sodium battery. A team led by a researcher named Chris Johnson has created a more exotic electrode made of vanadium pentoxide, able to withstand about 200 charge cycles using the same element sodium as electrolyte.
For comparison, the most accessible Li-Ion batteries currently available can withstand a minimum of 300 cycles of charge / discharge, without losing significant energy storage capacity.
The transition to the new type of battery could increase the autonomy of devices without raising too much the final costs. But the real challenge is finding a way to store more energy without increasing the physical dimensions of the battery. Unfortunately, in this matter Li-Ion batteries and Na-ion are equal, currently the only advantage of the latter is the fact that it is cheaper.