Why the Sodium-ion Battery Could Eventually Displace Lithium Batteries

julian-renpenni · ‎12-21-2022

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Rechargeable electrochemical batteries, as one of the most versatile energy storage technologies, play a central role in the ongoing transition from fossil fuels to renewable energy for achieving a greener planet. They are the key tools to lower the CO₂ footprint of both vehicle transportation and power grid sectors. The use of lithium-ion batteries as one of the most advanced energy storage technologies has grown significantly in recent decades. They offer some distinct advantages and improvements over other forms of battery technology, including nickel metal hydride, lead acid batteries and — of course —nickel cadmium batteries.

As a result, lithium-ion technology is being used increasingly for a vast number of widely varying applications: from small electronic devices to smartphones and laptops, to vehicles and many other applications.

Today, lithium gets most of the attention when it comes to battery technology, but its downstairs neighbor on the periodic table could eventually displace it. Certainly not entirely, but partly. Find out why in this blog post.

What is a sodium-ion battery?

Research on sodium-ion batteries began as early as the 1980s. So, this technology had a long way to go. After almost four decades sodium-ion batteries are garnering attention as technological advancements suggest that, compared to lithium-ion batteries, they may achieve not as good but almost similar performance in a wider range of applications without the supply chain headaches.

Rising demand for lithium-ion batteries has caused the price of, for instance, lithium carbonate to skyrocket with an almost 10-fold increase from 2020 to 2022 (Source: Trading economics). In contrast to lithium and some of the other key elements that are essential cathode active material in batteries, sodium has an almost unlimited supply. Its availability makes it by far less expensive and more environmentally friendly to source. The concentration of sodium in the Earth’s crust is about 500 times that of lithium, and it can also be extracted from seawater. In addition, sodium-ion batteries are also safer because they are nonflammable and less susceptible to temperature changes than lithium-ion batteries.

What are the differences between sodium-ion and lithium-ion batteries?

The chemistry and electrochemistry of electrode materials for sodium-ion batteries are different from that of their lithium-ion counterparts, using different electrolytes and chemicals. A quite significant one is the higher molar mass of sodium (23 g mol−1 vs. 6.9 g mol−1 for Li+) and larger ionic radius (1.02 Å vs. 0.76 Å for Li+). Also, the cathode material in sodium-ion differs from lithium-ion batteries. The three main types of cathode materials for sodium-ion batteries are oxide, polyanions and Prussian blue analogs. But currently there is no clear trend on which class of cathode materials should be the main target for successful commercialization. Still, its structure and working principle are quite similar to that of lithium-ion batteries. When both types of batteries are charged through the electrolyte, ions move from cathode to anode, and discharged if ions move into the opposite direction.

Are sodium batteries better?

Sodium-ions batteries have some major benefits that are going to challenge lithium-ion batteries. These include:

High abundance and lower price of sodium salt as raw material
Characteristics of sodium salt allow use of low-concentration electrolyte
Aluminum foil can be used as the current collector for the negative electrode, which can further reduce the cost
Can be charged to more than 80 percent in only 15 minutes at room temperature
Can operate over a wide temperature range and do not suffer from the effects of extremely low temperatures
Battery material is easier to recycle, making sodium batteries more sustainable

Like any battery chemistry, sodium-ion comes with its own tradeoffs. The biggest downside is that sodium-ion batteries have, in general, a lower energy density than lithium-ion batteries. This means an EV with a sodium battery that’s the same size as a standard nickel-cobalt-aluminum oxide (Li(NiCoAl)O2, NCA) or nickel-manganese-cobalt oxide (Li(NiMnCo)O₂, NMC) battery would not be able to travel as far on a single charge. However, most recent sodium batteries provided energy densities close to the lithium-iron-phosphate (LiFePO₄, LFP) type batteries, which is already applied in electric vehicles. And further improvements can be expected soon.

What kind of analytical techniques are required for battery development?

Evaluation of batteries and battery components requires a variety of analytical methods that study materials and component surfaces at various scales. Here I would like to briefly highlight various analytical techniques that are applied in battery material analysis:

Discover here how to perform elemental and structural analysis in battery material testing.

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Find out more about the battery material analysis portfolio here >

Conclusion

Sodium-ion batteries are considered one of the most promising alternatives to lithium-based battery technologies. The major advantage of sodium-ion batteries is sustainability, which is important for a world aiming to be free of carbon-based energy sources. Sodium-ion batteries with cobalt-free cathodes might become sustainable lower-cost alternatives to lithium-ion batteries for applications such as short-range electric vehicles and large-scale energy storage (ESS) in a world that is increasingly being transformed to wind, solar and hydroelectric power. Sodium-ion batteries could be used for various applications and potentially easing some of the supply constraints on raw materials for the lithium-ion batteries needed for EVs. The lower environmental footprint may also play a key role for various application fields and regulations.

Chinese battery giant CATL already introduced its first generation of sodium-ion batteries, and a number of startups also are working on increasing manufacturing capacity for sodium-ion production. UK-based Faradion has been focused on sodium batteries since 2011. HiNa Battery Technology in China, Tiamat in France, Altris AB in Sweden, and Natron Energy in the United States are all commercializing sodium-ion tech as well. So, we can expect this type of battery to appear more frequently over the next years.