The Many Ways To Make A Battery
Battery makers are constantly innovating in a race to make the best technology. In recent years, this has been driven by the incentive to capture the ever-growing EV market and the nascent but even quicker-growing utility-scale battery market.
Once built on lithium-ion technology, batteries are looking beyond this design to solve the issues of Li-ion: too expensive, using rare metals, fire risks, etc.
Source: Research Gate
One such alternative is sodium-ion, which utilizes sodium instead of lithium at the cost of lower energy density.
Another alternative is solid-state batteries. By removing the need for electrolytes, they can be denser and, therefore, require less of them for the same EV performance. Solid-state batteries should also be much quicker to charge.
Other more daring approaches do not simply change the chemistry but the structure of the battery itself. Notably, anode-free batteries remove entirely a part of the battery.
Researchers are now looking to combine these approaches together, notably with the recent publication of a design for the world’s first anode-free sodium solid-state battery.
Anode-Free Sodium Solid-State Battery
Published in Nature Energy under the title ”Design principles for enabling an anode-free sodium all-solid-state battery“, the researchers from the University of California and University of Chicago have not only created a solid-state battery, but one using sodium instead of lithium, and without even an anode.
Sodium Battery
Sodium is a very abundant ion, virtually in unlimited amounts in the ocean, 1,000x more abundant on Earth’s crust than lithium. This makes it a very good alternative to lithium.
It is important because lithium is hitting several limitations due to the EV boom:
- It is too expensive, making electrification itself too expensive.
- Its extraction is environmentally damaging.
- Produced only in a few places in the world and mostly refined in China, causing geopolitical risks.
Because it is so omnipresent and abundant, it is very unlikely that sodium will ever experience the price instability and shortage that lithium experienced in the last years.
The issue is that sodium batteries are usually not really dense enough to compete with lithium-based batteries, except for low-price EV models.
Anode-Free Battery
Normally, a battery has an anode that stores the ions while the battery is charging. They then flow back toward the cathode when the battery is releasing its energy.
Anode-free batteries instead store the ions in an electrochemical deposit of alkali metal directly on the current collector.
This allows for higher cell voltage, lower cell cost, and increased energy density.
Source: University Of Chicago
The issue with an anode-free design is that the current collector tends to see a deposit build-up from the liquid electrolyte, leading to damaging the battery.
Solid-State Battery
Solid-state batteries have long been expected to be the “final” form of battery-based energy storage, especially for applications requiring very high-density mobility.
Removing the electrolyte reduces the total battery weight and makes the battery very quick to charge and discharge.
The issue with these designs is usually to manage to have a solid enough system, as metals tend to swell when charging.
In addition, the issue of growing dendrites that can create shortcuts (and therefore fire) is always looming in the background, like with lithium-ion batteries.
Anode-Free Sodium Solid State
In the context of an anode-free design, an additional issue is that a classical solid electrolyte cannot properly interact with the current collector.
The researchers solved this issue by using aluminum powder as a current collector, which is a solid that can flow like a liquid.
Source: University Of Chicago
Many benefits
By being solid, the aluminum electrolyte also prevents the formation of dendrites, the main cause of too short lifespan of solid-state batteries.
It also provides a stable interface and avoids to see some of the sodium inaccessible to the current which would reduce the battery capacity.
Lastly, it allows for high energy density, with the different options for this sodium-solid-state battery ranging all in the 200-400Wh/kg density.
Source: University Of Chicago
While this is a bit lower than lithium-based solid-state batteries, it is still a lot stronger than currently used batteries. Combined with the economics of much cheaper materials, with sodium and aluminum replacing lithium, cobalt, and nickel, it could be a winning combination.
The Power Of Combination
Even a few years ago, the idea of sodium batteries, or anode-free batteries, was only a concept that many doubted would reach a commercial stage. The same can be said for solid-state batteries.
This is quickly changing for every one of these categories, as well as plenty of other potential chemistries and designs we explored in our articles “The Future Of Energy Storage – Utility-Scale Batteries Tech” and “The Future Of Mobility – Battery Tech”.
It seems we are entering a new stage, where researchers are now looking at all these now-proven battery concepts and starting to merge them together.
Surprisingly, it might help overcome the individual limitations of each idea.
In this example, both solid-state batteries’ dendrite issues and anode-free design’s issue of deposit on the current collector get solved by using aluminum powder.
Aluminum powder alone on an anode-free design would still yield too low density.
Aluminum powder in solid-state batteries would not be cheap enough without using sodium.
Meanwhile, sodium alone is cheap but not dense enough to meet the requirement for mobility.
So it seems that combining different design elements can help bring together their respective advantages while also removing or at least attenuating their individual issues, creating a much larger set of future opportunities for innovative battery chemistries than previously thought.
Sodium Battery Companies
1. CATL
CATL is the global leader in battery manufacturing, producing more than half of the global battery volume. The company is present at every step of the battery manufacturing supply chain and is a leader in battery technology.
This is true for lithium-ion batteries, where the company has been a long-established leader for a long time. CATL has also announced impressive progress on multiple other battery types :
Source: CATL
The company is getting active in the utility-scale battery market, with the announcement of its TENER system performance. It is “the world’s first mass-producible energy storage system with zero degradation in the first five years of use in Beijing, China”.
Immense Energy in a Compact Space: 20-foot Container with 6.25 MWh Capacity
Powered by cutting-edge technologies and extreme manufacturing capabilities, CATL has resolved the challenges caused by highly active lithium metals in zero-degradation batteries, which effectively helps prevent thermal runaway caused by oxidation reactions.
CATL has also invested 3.25B in battery recycling capacities in China. CATL has notably achieved a remarkable recovery rate of 99.6% for nickel, cobalt, manganese, and 91% for lithium.
Thanks to its scale, focus, and R&D achievements, CATL is likely to be at the forefront of battery innovation, manufacturing, and recycling. This makes it a key partner for EV manufacturers, including Tesla, NIO, Ford, Stellantis, etc.
2. BYD
A long-time challenger of Tesla in the EV market, BYD has become a serious competitor not only for Tesla but for virtually all automakers.
The company evolved from its origin as a phone battery supplier to selling almost as many EVs as Tesla in China (the world’s largest EV market) and being the best-selling EV in Thailand, Sweden, Australia, New Zealand, Singapore, Israel, and Brazil.
BYD is a large part of why China suddenly became the world’s largest car exporter in 2023, surpassing Japan. The company’s aggressive overseas expansion is also carried by new factories, like in Hungary.
And with the release of $10,000-$12,000 cars like the Seagul, using sodium batteries, a whole new market might open for BYD EVs.
Source: By User3204 – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=142412738
Still at its core, a battery manufacturer, BYD is a serious challenger to CATL in the LFP battery market, with a 41.1% market share in China (compared to CATL’s 33.9%).
The “flood” of cheap EVs produced by BYD into the European and American markets is likely to be met with some level of protectionism (even above the recently imposed tariffs), which could hinder BYD’s growth.
But at the same time, cheap Chinese EVs are already a great success in the rest of the world, which does not have incumbents much in the way of domestic automakers to protect, including the entirety of South America, Russia, Africa, the Middle East, and Southeast Asia.
This represents several billion potential customers for BYD, living in countries eager to strike a geopolitical balance and stay on good terms with both the West and China, so it is unlikely to create too strong protectionist barriers.
And even in the EU or the USA, BYD might stay competitive, thanks to the much higher prices of local EV manufacturers compared to prices in China, as well as localization of the production out of China for these markets, like, for example, in Eastern Europe, Mexico, or Turkey.
