Battle for Better Batteries

by Hydrolycus

Rechargeable batteries are found in all the things, big and small, that make modern societies tick.

Thanks to their ubiquity, it is easy to take batteries for granted, but in doing so we ignore the undeniable fact that our choice of rechargeable battery is a choice that has real-life consequences in environmental, financial, as well as geopolitical terms.

So let's start at the very beginning, allegedly a very good place to start.

The Heavy Metal Era

The lead-acid battery was the first practical rechargeable battery.

Invented by the Frenchman Gaston Planté in the late 1850s, it's inexpensive to manufacture and capable of delivering plenty of current features that have led to it still being the most widespread battery used in internal combustion vehicles and stationary installations.

In spite of its popularity, it's not without problems.  First of all, it has a poor power-to-weight ratio.  Lead, one of the battery's principal components, is as heavy as - well, lead actually, a fact that makes it unsuitable for portable devices.

It gets worse.

The other principal component is sulfuric acid.  In practical terms, a leaky battery in your phone could give you a one-time free dermabrasion.  The charge/discharge cycle of a lead-acid battery releases highly combustible hydrogen gas, creating a potential Hindenburg scenario in poorly ventilated spaces.  And then there's the disposal problem.  Lead in all its forms is poisonous to humans and many other living organisms, necessitating strict disposal and recycling protocols for the batteries.

Nickel Ain't Worth a Dime

Nickel is a much lighter metal than lead.

It's relatively inexpensive, and nickel oxide hydroxide also happens to be a good material to make battery electrodes from.  Several different chemistries have been developed, and such batteries can be made quite small, making them viable in portable devices.

But as you probably guessed, nickel-based batteries have their own set of problems.

The batteries have very real limits on the number of times they can be fully recharged from a partial discharge, the "memory effect" we've all come to hate.  They also have problems with polarity reversal if they are discharged too deeply, a phenomenon that can kill sensitive electronics along with the battery.  The trick would be to discharge the batteries fully but not too fully before recharging.  And even if you are astute enough to pull that off, there's a gotcha: self-discharge through internal leak currents.

Although nickel isn't very toxic by itself, it is often partnered with cadmium in batteries, and cadmium is an extremely toxic metal that you don't want in your local landfill, unless you have a fetish for kidney failure and spontaneous bone fractures.

A Cure for the Blues: Lithium

So far we've painted a pretty depressing picture of rechargeable batteries (pun intended), but for the longest time it was all we had and we learned to live with it.

Then the 1980s came upon humanity, bringing with it blessings like big hair, Members Only jackets, boomboxes, ferns, and Full House.  And lithium.

Lithium is the lightest of all the metals, juxtaposing it as a Barry Manilow to a heavy metal like lead's Iron Maiden.  It is also happy to give away and accept back electrons, with none of nickel oxide hydroxide's fussiness.  Put those facts together and we could have a recipe for battery chemistries suitable for portable devices as well as electric vehicles.  And, sure enough, there are dozens of battery types based on lithium.  So all's well, then?

Hardly.

Lithium is a poisonous metal, posing a danger in humans to the kidneys and the nervous system.  Somebody might protest that the small quantities used in, for example, a cell phone or a music player aren't a big deal in the overall scheme of things.  But imagine the day when discarded lithium-based batteries of tens of millions of electric cars and other vehicles end up in landfills across the globe.

Disposal is not the only problem associated with lithium.

The mining and refining process of lithium consumes mind-boggling amounts of another scarce resource: water.  It takes two million liters of fresh water to make one ton of lithium.  One ton of lithium is a lot, right?  Actually, no it's not.  One ton of lithium is barely enough to make batteries for perhaps 90 small passenger cars.

Then there are the financial considerations, and those include more than just the high cost of extraction.  Lithium is a relatively rare metal.  The worldwide reserves are on the order of 20 million metric tons.  Most of the reserves are located in China, with other extractable deposits in Australia, Chile, Argentina, and the Democratic Republic of Congo.  Much of China's production is earmarked for domestic consumption, and a sizable chunk of the contracts for the output of other countries is already spoken for by a handful of corporations.  In effect, there's a monopoly in place, keeping prices artificially high.

China's dominance in the lithium market has obvious geopolitical consequences, as it could be used to pressure other countries, especially with the world's growing dependency on lithium batteries.

Similar situations exist for many of the other key ingredients in lithium batteries, such as cobalt, copper, graphite, and others.

Finally, we have to mention lithium-based batteries' claim to popular infamy.  They're prone to runaway thermal reactions that can cause them to catch fire.  Your ears could literally be burning if that happens to your phone's battery.

At this point, it would be fair to ask if there is a way to make good, usable, rechargeable batteries without either killing the planet, going bankrupt, or starting World War III.  It turns out that there might be.

Sodium: A Salt and Battery

The metal sodium sits on the next rung of the periodic table right above lithium.

Given that position, it's reasonable to ask if it has chemical properties similar to lithium.  The answer is that it does.  It's highly reactive in the sense that it's willing to give up electrons, but also take them back - the fundamental idea of rechargeability.  In fact, metallic sodium is so reactive that it will catch fire if exposed to air!

Sodium is abundant on our planet, and not only in cheap snack foods and hipster spas.  Our oceans are full of sodium, and there are rock deposits all over the world.  Thus, there are no geopolitical complications to overcome.  Our blood and the cells of our bodies are jam-packed with sodium chloride, as are all other living cells, living proof that it's not toxic if enjoyed in moderation.  And to top it off, it's relatively inexpensive to extract from the many sources that exist.

So the final question then becomes: Could we make sodium based batteries?  We not only can, we already are making them.  CATL, the world's largest battery producer has developed the technology, and by the time you're reading this they have probably reached the market.  But they were not first.  Several companies, for example British firm Faradion, are already shipping large-capacity sodium-based batteries to customers.

The Low-Sodium Alternative

There is even more good news on the horizon.

Several companies are making progress developing "green" batteries from organic sources.  Huh?  Organic batteries?

One of the most promising organic battery technologies is based on peptides.  Peptides are simply chains of amino acids, the stuff that proteins are made of.  There are 20 naturally occurring amino acids, and each have slightly different chemical properties.

Depending on the order in which the specific amino acids are linked together, we end up with peptides and proteins with widely varying characteristics, some of which can be used to make rechargeable batteries.  This is thanks to the electrical properties of various amino acids.  Some of them - for example aspartate and glutamate - have a negative electric charge, whereas others - for example histidine, arginine, and lysine - have a positive electric charge.

What's so great about organic batteries?  First of all, the chemicals inside them are fully biodegradable.  There are no poisonous metals to worry about.

Second, since proteins are the building blocks of all living matter, there are plenty of cheap amino acids to go around if you know where to look for them.  Batteries have successfully been created from farm- and forestry-waste that would otherwise be burned or left to rot!  Nobody goes to war over farm waste.

One final, very interesting property of peptide-based batteries is that the charge time is much lower than what we get from lithium batteries.  Imagine fully charging your Tesla in 30 minutes!

This technology is developing rapidly, and there are several pilot studies underway, primarily targeted at making batteries for electric vehicles.

All in all, there is hope for a future beyond lithium and lead.   t's not a matter of technology anymore, it's a matter of economic and political initiative.

Shout-outs to Joao, Saravanan, Rav, John, and Kirk.