Electronics

Sodium-ion battery beats lithium for cost effectiveness

Sodium-ion battery beats lithi...
A sodium-ion battery, designed at Stanford, can store as much energy as a lithium-ion battery for less than 80 percent of the cost
A sodium-ion battery, designed at Stanford, can store as much energy as a lithium-ion battery for less than 80 percent of the cost
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A sodium-ion battery, designed at Stanford, can store as much energy as a lithium-ion battery for less than 80 percent of the cost
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A sodium-ion battery, designed at Stanford, can store as much energy as a lithium-ion battery for less than 80 percent of the cost

Lithium-ion batteries are the current reigning energy-storage champion, powering everything from phones to cars. But as good as it is as an electrode material, lithium is relatively rare, and the cost of mining and refining it can blow out the budget for large-scale applications. The search for a cheaper alternative has led some scientists to plain old salt, and now a Stanford team has developed a sodium-ion battery that would beat lithium-ion batteries in terms of cost per storage capacity.

As our oceans and dinner-table shakers show, salt is everywhere, and its ability to carry a charge makes it a perfect low-cost energy storage candidate. Sodium-based batteries are making in-roads in various forms, from the standard 18650 format used in laptops, to a quirky design with an anode made of a carbonized oak leaf.

"Nothing may ever surpass lithium in performance," says Zhenan Bao, lead researcher on the Stanford study. "But lithium is so rare and costly that we need to develop high-performance but low-cost batteries based on abundant elements like sodium."

The Stanford team's design uses a sodium salt cathode where positively-charged sodium ions are bound to negatively-charged myo-inositol ions, and a phosphorus anode – all materials that are naturally abundant. The researchers say they studied the atomic-level forces at work in how the sodium ions attach and detach themselves from the cathode, in order to improve the charge-recharge cycle.

In the end, the cathode of the sodium-ion battery has a reversible capacity of 484 mAh g−1, and an energy density of 726 Wh kg−1. The energy efficiency of the new batteries is claimed to be more than 87 percent, and as for the all-important factor of cost, the researchers claim this could add up to a sodium-ion battery that approaches lithium-ion batteries in terms of performance, but would cost less then 80 percent of a lithium-ion battery with equivalent storage capacity.

The next steps for the team is to fiddle with the phosphorus anode, which should squeeze more performance out of the sodium-ion battery. To properly compare their creation to lithium-ion batteries, the team also plans to examine the volumetric energy density of the device, which dictates how big a battery needs to be to store a certain amount of energy.

The research was published in the journal Nature Energy.

Source: Stanford University

Update (Oct. 11, 2017): This article originally stated the battery had "a reversible capacity of 484 mAh g−1, and an energy density of 726 Wh kg−1" – those figures refer to the cathode. We apologize for the error, which has now been corrected, and thanks to the commenter who pointed it out.

6 comments
Bruce Golden
Micheal --- I am not finding any 18650 battery products for sale ... was nice picture from the earlier posting but frankly is a stretch to claim cheaper than Li-Ion if no commercial sodium product.
stabilizer
There are batteries that are cheaper than lithium ion. There are batteries that are smaller than lithium ion. There are batteries that are lighter than lithium ion. None are as cheap, light, and small as lithium ion. The key to the portable device market is finding a battery that is cheaper, lighter, and smaller than lithium ion. Right now, batteries are available that are a better choice for home power. We are close on electric car battery technologies. Phones and laptops - not yet. Lithium ion has two flaws that drive the search for a replacement. First, it's not practical to recycle the Lithium. Second, lithium ion doesn't last forever. If lithium can be make to last forever, it wins. If lithium can be recycled, it wins. I'll make a prediction - lithium ion suppliers will figure out how to recycle lithium ion batteries before we find a superior technology.
noteugene
Your prediction has already proven false. Article other day showing a car manufacturer that had just developed a battery that beat existing batteries as to mileage range per charge. Forget the details but you should be able to find it.
ljaques
The big problem with lithium battery price is that too many "investors" have muddied the futures waters of lithium, sending the price into the sky. That said, I wish Elon luck in sourcing enough to get the GigaFactory up to full production which will drop the price for lithium batteries. Also, new research into lithium looks to triple the output and lower the charge time. (see other NewsAtlas article from a couple days ago)
Gene Preston
If the sodium ion battery has a long life and is suitable for stationary service such as at substations and home microgrids, then there is definitely a role for this battery to play even if it is not suitable for cell phones and EVs.
Paravectorno Extactini
Ha, for those stocking up on 100 packs of AAs for the holidays and wishing they could be rechargeable other teams are focusing on cost (and not harvesting volcanoes for a steady supply of lithium) as illustrated in this special: http://www.cell.com/joule/fulltext/S2542-4351(17)30089-2 Again, the batteries are not yet being commercially produced! It has to be awesome enough ways...