China has Made A Water Based Battery: But Does it Live up to the Hype?

Change the fundamentals, and you’ll change the world. In a megaproject-obsessed modern era, the ultra-tall skyscraper concept art, the flying cars that never actually arrive, and, yes, the hundreds-of-kilometers-long linear skyscraper city in the Saudi Arabian desert, seem to get all the headlines. But it’s the more down-to-earth sort of inventing that really makes the world go round, the sort of inventing that lets you play slide-shows really fast as if you’ve made a moving picture, or that makes a cooking box filled with special energy that lets you have hot food anytime you want. If you think faster-than-light travel is cool, just imagine how much less cool your life would be without the flush-toilet or beer you can keep in a can. It’s improvement on the basics that makes this whole world work, today just as much as ever.

In the 21st century, few fundamental improvements have more potential to make a change, than figuring out how to improve the battery—and in 2024, a team of scientists out of China announced that they’d made a breakthrough. According to their research, a revolutionary water-based battery has the potential to turn the world upside-down, and open the door to an entirely new way of thinking about energy itself. Today on Megaprojects, we’re going to ask three key questions about this purported new battery: How does it work, why is it important, and most important of all…is it any good?

The Importance of Better Batteries

Now, before we get into the new battery technology on the horizon, we’re going to take a brief moment to review the basics: What are batteries like now, and how do they work? We’ll spare you the in-depth explanation, although the battery nerds in the comments section would be happy to oblige if you’d like to know more, but the basics behind the technology go as follows. The vast majority of rechargeable batteries today are lithium-ion batteries, which hold a respectable amount of energy in a package that can be scaled up, for things like cars, scaled down, for things like smartphones, and plugged back in anytime they need some more juice. These batteries use two pockets of stored lithium, referred to as an anode and a cathode, and send positively charged lithium ions from the anode to the cathode, and vice versa, by traveling through a separator—which, you can probably guess, keep the anode and the cathode separate. The movement of lithium ions causes them to basically jettison off a bunch of electrons; those so-called “free electrons” are what creates an electric charge, and that charge is then used to power all the stuff that makes the world go. Simple enough.

Lithium-ion batteries are all well and good, but humanity has been pushing against their outer bounds for years now. To put it simply…they can’t hold enough energy. They’re still improving, year over year, but in small and incremental improvements that aren’t likely to change the game anytime soon. That’s a problem, because the rest of human technological progress is very much prepared to start changing the game, in all manner of ways. We’ve got the technology to make crazy electric cars that could run for incredible durations without ever needing to stop, but lithium-ion batteries can only give them a few hundred miles, kilometers, whichever you prefer, of power before they need a recharge. We’ve got the technology to fly internet-repeater drones over the entire world indefinitely, and bring internet access to every person on Earth…but lithium-ion batteries can only keep them flying for so long. We’ve got the technology to build all sorts of implanted medical devices…but only if a person is willing to either have it scooped out every so often for a battery change, or get the kinds of body modifications that would put a Lightning charge port in their belly button. And we have the requisite technology to harvest incredible amounts of energy from the Sun, the air, the Earth, and the atom…but not nearly enough ability to store that energy for the long term. To put it simply, lithium-ion batteries are becoming a bottleneck to all manner of technological innovation, in fields where we have all we need to be successful…but just can’t store energy to the extent that’s required.

Not only that, but lithium-ion batteries have also got a number of intrinsic problems. They’re prone to overheating, and cause some nasty fires and toxic gases when they experience uncontrolled failure. They rely on materials like cobalt and nickel, elements that are extracted from the Earth at great expense to local environments, and there are multiple wars being fought over each of those elements as we speak.

Go check out our sister channel Warographics, if you’d like to learn more. Nor can they be recycled, meaning that making more lithium-ion batteries is functionally the same thing as making more landfill space. And new research also suggests that they leave behind quite a lot of so-called “forever chemicals”—or, to move past the buzzword, they contain a whole lot of perfluoroalkyl and polyfluoroalkyl substances that are very, very hard to get rid of, lead to lots of health problems in humans and animals, and are, as it turns out, basically everywhere.

Reassuring stuff.

There are alternatives to lithium-ion batteries today, but they’ve all got their own issues, from being far harder to miniaturize, to being more volatile and unstable, to not being as easily rechargeable or not being rechargeable at all…that kind of thing. There are ongoing efforts to see if those batteries can transfer over, and fill some of the needs that lithium-ion batteries aren’t sufficient for. At the same time, there are efforts to get lithium-ion batteries to be a little more efficient, year-over-year, and make incremental progress toward some of these broader worldwide goals. But if humanity is going to get to the places where it seems to be headed, it’ll have to be some other piece of technology, not the lithium-ion battery, that gets it there…and that means that the race to develop something better, has the potential to be one of the most earth-shaking, and potentially lucrative technological competitions that nobody seems to be talking about.

Building a Battery

It was against that backdrop that in April 2024, the Nature publication—via its Nature Energy journal—published a study by way of a team of six researchers, working out of the Chinese Academy of Sciences. The study is a rather dense one, and rather than go through all the technical elements, we’ll hit you with the biggest takeaway first. Using a water-based design, in a so-called “aqueous battery”, the research team created a battery that, in laboratory settings, achieved a performance of 1,200 watt-hours per liter—a unit that basically quantifies how much energy a battery can hold, relative to the mass of the material it uses to store that energy. The figure the research team found, 1,200 watt-hours per liter, is nearly double the performance of modern lithium-ion batteries, at just a measly 700 watt-hours per liter—and that’s just the results from this early study in lab settings, well before the minds and money of global industry get involved.

The battery works by relying on a water-based solution using ions of two other elements: iodide, an ion of iodine, and bromine, an ion of bromine. By mixing the two ions with water in an acidic solution, the scientists were able to prompt a chemical reaction that turned the iodide into iodine, and then into another ion, iodate. Adding bromide to that process formed what’s called a mixed-halogen electrolyte, basically a solution that takes the number of free electrons found in typical lithium-ion batteries, and boosts that number through the roof. Using specially built anodes that were made from the elements cadmium and vanadium, the research team was able to construct full batteries that were more energy-efficient than lithium-ion ones, and, perhaps just as important, were already suspected to be cost-competitive, meaning that even if they were a little more expensive than lithium-ion batteries, people would still be paying roughly the same or less per unit of energy storage. And not only that, but these batteries can last, too: per the research team, their battery can last over a thousand cycles of charge and discharge. By contrast, the battery of the standard iPhone 14 is designed to last just half that, 500 complete charge cycles, under ideal conditions…while losing up to 20 percent of its capacity over that time.

Even before this particular study was published, the idea of aqueous batteries wasn’t anything new. Water-based batteries have been understood decently well for some time, and they’re widely considered to be much safer than lithium-ion varieties. They’ve got their own problems, however, particularly the fact that they operate in a pretty narrow voltage window—meaning that they can’t really operate at too high a voltage without degrading over time.

They’re also not very energy-dense, meaning that even if they’re safer and more stable, you can’t actually store that much energy in them. Those aqueous batteries, however, typically only use iodine ions—and here, it’s the addition of bromine ions that made all the difference. Bromide caused the critical, energy-generating chemical reaction to happen more, and faster, but it also stopped byproducts from forming—and specifically, stopped the formation of the byproducts that degrade these very same batteries over time.

With that single tweak, the batteries became far more energy-efficient and saw a considerable rise in their storage capacity, while also addressing all the issues that aqueous batteries usually suffer from, and not losing out on any of their advantages. To put it simply, this new design is reported to offer improvements over lithium-ion batteries in every metric—and if those improvements can be shown in the real world, then the entire way the world works, could shift on a dime.

What Does This Mean?

When we turn to the actual implications of these aqueous batteries, it’s important to begin with caveats…in a few different directions. First, there are the more pessimistic elements we’ve got to acknowledge: not only are these batteries just a laboratory finding, but at least to our knowledge here on Megaprojects, they have yet to be reproduced and verified by other researchers from other institutions. That sort of external validation is very, very important before we take any groundbreaking scientific discovery seriously, and at least for the time being, it’s lacking here. But, that being said, these are the sorts of results that will likely get other organizations carrying out reproducibility studies fairly quickly, and that brings us to a far more positive caveat. If this design really does work, then it’ll very quickly be seized on by global industry, working to create similar batteries or even improve on it—and there’s no telling how massive those improvements might eventually become. Every mega-corporation, every industrial sector, and every scientific initiative that can benefit from better batteries, are going to be very interested in these designs if they can be shown to be reliable.

As for whether this research itself is reliable, it’ll come down to reproduction studies to show either way. While the study is likely to raise the hackles of skeptics mistrusting the close links between China’s science and academia, and the political aims of the Chinese Communist Party, the truth of the matter is that China now produces more high-quality scientific research than anywhere else on Earth. Close links to the state do mean political advantage in seizing on optimistic or seemingly groundbreaking findings, but they also mean a whole lot of money allocated to research in the country—and by a wide range of international metrics, the investment has led to some truly excellent research. The institution that churned out this particular study, the Chinese Academy of Sciences, is among the best of the best regardless of nationality—and this particular study isn’t likely to include sweeping false claims or scientific bluffs. The study clearly outlines the process required to create this specific type of aqueous battery, using materials that researchers from any developed nation can get their hands on and try to replicate. Give it a bit of time, and the world is likely to find out quite decisively whether this approach to battery technology is any good.

In terms of the technological advancement that could be possible, if these batteries do work as advertised, it’s honestly difficult to find ways to overstate it. Handheld devices and personal electronics could become significantly longer-lived, both getting through many more recharges before they begin to degrade internally, and lasting for longer each time they’re charged—to the point that carrying charging cords around everywhere, could become just as retro as carrying around a boombox on your shoulder. The electric-car industry would see major improvement, with electric vehicles able to boast a range doubling what most gas-fueled cars can do on a full tank.

Grid-scale electrical storage would become far easier, drastically reducing the number and size of batteries necessary to keep reserve power for renewable energies, and thus substantially improving the utility of wind turbines, solar cells, and more. That’s just scratching the surface, but it’s truly difficult to do justice to all the myriad implications here. Think of an element of everyday life where rechargeable electric batteries are used, and you’ve thought of a part of life that could be radically improved, if these aqueous batteries can catch on.

And all that, with far less risk of overheating or of harmful battery failure, no problem with forever chemicals, far easier and less harmful waste disposal, and so much more.

And with a different subset of elements used, these aqueous batteries can lead to major changes around the world, specifically when it comes to competition over precious resources. As we alluded to before, many of the critical materials used in modern electronics can only be found in a few places; cobalt, by example, is highly concentrated in the Democratic Republic of the Congo, where war rages and countries have competed for a decade to exploit the resource by any means necessary. Nickel has been implicated as a root cause in major unrest in the French territory of New Caledonia, the one place in the world where Europe and the United States can get the stuff without having to ask potentially hostile nations like Russia and Indonesia, or having to rely on vulnerable nations like the Philippines. Rare-earth elements can be found all over the world, but are produced mostly in China, making them a huge potential flashpoint anytime tensions flare up between China and its adversaries.

But iodine, one of the critical materials used to build these sorts of batteries, can be harvested from seaweed all over the world, and it’s produced not just in Russia and China, but Western-allied Japan and Chile. Bromine can be extracted from salt lakes all over the world, with the US, China, and nations of the Middle East accounting for the highest shares of production. Cadmium is a relatively abundant heavy metal around the world, and vanadium can be found not just in ore reserves in Russia and China, but all across America’s Colorado Plateau, known for the Grand Canyon and a whole range of other national parks. While we certainly wouldn’t make the claim that switching to aqueous batteries is a path to world peace, we do need to emphasize that reducing reliance on scarce, highly exploited natural resources, however that happens, leads people away from international conflict, not toward it. With the universal importance of battery technology, it’s a real, meaningful change to be able to relieve pressure on global mining and resource production, by taking lithium-ion battery production off the board.

And there’s even greater potential benefit around the world, when we account for the potential for lower-risk, longer-lasting, better-storage batteries to be sent around the world. Energy is a scarce commodity in many parts of the developing world, and certainly, there are a range of problems that simply sending more batteries, won’t be enough to solve. But sending better batteries certainly doesn’t hurt, and sending batteries with double the storage capacity and double the lifespan, makes it easier to do more in developing communities even with power infrastructure lacking. China, in particular, might be able to work these batteries into a broader solution for developing nations—namely, its initiative to build portable nuclear reactors and potentially send them to remote or under-powered regions around the world. Add the capacity for better power storage, and on the one hand, communities can better rely on these reactors despite the fact that they present a single point of failure. On the other hand, it also could become much easier and much less risky to use those reactors as a central generator, and send stored energy into smaller or harder-to-access communities using this same battery technology. That’s just one example of a broader reality: that by using better batteries, and batteries with higher storage capacity, it makes more sense for people to harness sources of abundant energy in one place, and send that energy elsewhere. It doesn’t make sense to build, say, a hydroelectric dam on a raging river if only a few people live close enough to build power lines…but if that same energy can be stored and shipped a few hundred kilometers in each direction, it can power a hell of a lot more communities than the ones living in proximity to that river.

All this, of course, and we’re still forced to acknowledge the possibility that perhaps, none of this will work at all. Again, this is one single study, and although there are reasons to be optimistic, there are no guarantees that the technology involved will ever be reproduced. That will take scientific investment, inter-organization and international cooperation, and, unfortunately, time. But if these aqueous batteries do function as promised, then we could very well be standing at the edge of a new revolution in energy—and there are a whole lot of technological breakthroughs just waiting to happen, as soon as that energy revolution arrives.

Key Takeaways

• Lithium-ion batteries are a bottleneck for technological innovation due to limited energy storage and environmental issues.
• A new water-based battery developed by Chinese scientists shows nearly double the energy density of lithium-ion batteries.
• The new battery uses iodide and bromine ions in a water-based solution, improving energy efficiency and longevity.
• If validated, this battery technology could revolutionize energy storage, benefiting electric vehicles, grid storage, and more.
• Reduced reliance on scarce materials like cobalt and nickel could decrease global conflicts over resources.

Sources

• Original MegaProjects video: China has Made A Water Based Battery: But Does it Live up to the Hype?
• Nature Energy - Aqueous Battery Study
• ThoughtCo - 20th Century Timeline
• U.S. Department of Energy - How Lithium-Ion Batteries Work
• Battery University - How Do Lithium Batteries Work
• UL Research - What Are Lithium-Ion Batteries
• The Verge - Forever Chemicals in Lithium-Ion Batteries
• Greenly - Harmful Effects of Lithium Batteries
• UNSW - Lithium-Ion Battery Safety
• ACS Publications - Battery Research
• ScienceDirect - Battery Environmental Impact
• Boston University - The Race to a Battery-Powered Future
• Saft - Three Battery Technologies for the Future
• S&P Global - The Future of Battery Technology
• Florida State University - Better Battery Design Research
• MIT Technology Review - What’s Next for Batteries
• RELion Battery - What Is Energy Density
• Live Science - Chinese Scientists Water Battery
• Interesting Engineering - China Energy Dense Aqueous Batteries
• Mining.com - New Water Battery vs Lithium
• MIT Technology Review - Water Batteries
• Nature - Energy Research
• Science - China Most Cited Papers
• Ohio State University - China High-Quality Science
• Nature - China Scientific Research
• The Economist - China Scientific Superpower
• Reuters - China Fourth Generation Nuclear Reactor
• Hero image source by Saudi press Agency (SPA) / openverse, by-sa.

Related Coverage