In the background is an actual scanning electron microscope image of a collection of these yolk-shell nanoparticles.
Some Scientists at MIT have broken the mould with a new type of battery that should obliterate the current lithium-ion batteries out of their comfortable ionic waters. The picture above shows the ‘yolk’ and ‘shell’ nanoparticle. The grey sphere at the centre is representing an aluminium nanoparticle (the yolk), and the outer light-blue layer is a solid shell of Titanium Dioxide.
The most important part in my humble opinion is the gap between the two; this space between allows the ‘yolk’ to expand and contract without damage to the ‘shell’. To understand this more, a few points need to be noted with the workings of the current batteries. Basically, the current tech of lithium-ion batteries allows them to expand and contract as they charge/discharge but the science behind it is different. The current batch reform and shed a ‘skin’ layer that consumes Lithium each time they charge/discharge, unfortunately, as the Lithium content drops, so too does the batteries capacity.
The idea behind the titanium dioxide “shell” and aluminium “yolk” scenario is that the metal can expand and contract without degradation. The result is a battery that not only has a greater capacity and charges faster but that also does not degrade much over time and charging cycles. Not bad considering the discovery was by accident!
So, with the potential ‘Yolk and Shell’ batteries making use of nanoparticles, smaller actually means more room and thus more expansion / contraction. The overall result, and the one that benefits you, the consumer, is that a battery with this technology can charge in just six minutes to full capacity and is also able to hold three times the charge of current lithium-ion offerings. The batteries themselves are not only a lot better but also cheaper to make. This means that these batteries are close to being mass produced very soon!