Lithium-Air Batteries are the Future, Still Many Years Away.

There’s no question about it: batteries just haven’t kept pace with technological innovation. This isn’t for lack of trying however, it’s just that there’s no direct means to increasing energy densities like there is for increasing transistor count. So what we have are batteries that are mostly capable however have not seen rapid improvement as technology has rocketed away to new heights. There are however visions for the future of battery technology that, if they come to fruition, could see a revolution in battery capacity. The latest and greatest darling of the battery world is found in a technology called Lithium-Air, although it becoming a reality is likely decades away.

ambl012_fig_2Pretty much every battery in a smartphone is some variant of lithium-ion which provides a much higher energy density than most other rechargeable battery types. For the most part it works well however there are some downsides, like their tendency to explode and catch fire when damaged, which have prevented them from seeing widespread use in some industries. Compared to other energy dense mediums, like gasoline for example, lithium-ion is still some 20 times less dense. This is part of the reason why it has taken auto makers so long to start bringing out electric cars, they simply couldn’t store the required amount of energy to make them comparable to gasoline powered versions. Lithium-Air on the other hand could theoretically match gasoline’s energy density, the holy grail for battery technology.

Lithium-air relies on the oxidation (essentially rusting) of lithium in order to store and retrieve energy. This comes with a massive jump in density because, unlike other batteries, lithium-air doesn’t have to contain its oxidizing agent within the battery itself. Instead it simply draws it from the surrounding air, much like a traditional gasoline powered engine does. However such a design comes with numerous challenges which need to be addressed before a useable battery can be created. Most of the research is currently focused on developing a cathode (negative side) as that where the current limitations are.

That’s also where the latest round of lithium-air hype has come from.

The research out of Cambridge details a particularly novel chemical reaction which, theoretically, could be used in the creation of a lithium-air battery. The reaction was reversed and redone over 2000 times, showing that it has the potential to store and retrieve energy as you’d expect a battery to. However what they have not created, and this is something much of the coverage is getting wrong, is an actual lithium-air battery. What the scientists have found is a potential chemical reaction which could make up one of the cells of a lithium-air battery. The numerous other issues, like the fact their reaction only works in pure oxygen and not air, which limit the applicability of this reaction to real world use cases. I’m not saying they can’t be overcome but all these things need to be addressed before you can say you’ve created a useable battery.

Realistically that’s not any fault of the scientists though, just the reporting that’s surrounded it. To be sure their research furthers the field of lithium-air batteries and there’s a need for more of this kind of research if we ever want to actually start making these kinds of batteries. Breathless reporting of progressions in research as actual, consumer ready technology though doesn’t help and only serves to foster the sense that the next big thing is always “10 years away”. In this case we’re one step closer, but the light is at the end of a very long tunnel when it comes to a useable lithium-air battery.

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