A very interesting study, which we have just learned about, reveals a sodium battery architecture with stable cycles for several hundred cycles. The novelty is that, by eliminating the anode and using sodium, this innovative battery will be more affordable and ecological. In addition, its solid-state design makes it much safer and more efficient.
How do we know? That’s what the inventors, scientists from the Pritzker School of Molecular Engineering at the University of Chicago, in collaboration with the Department of Chemical and Nano Engineering at the University of California, San Diego, say.Although sodium, solid-state and anodeless batteries already existed, no one had managed to successfully combine these three ideas until now.“, he declared Grayson Deyshera Ph.D. at UC San Diego and first author of the study published in Nature Energy.
Lithium, commonly used in batteries, is relatively scarce, accounting for about 20 parts per million in the Earth’s crust, compared to sodium, which accounts for 20,000 parts per million. This scarcity, coupled with rising demand for electronic devices and electric vehicles, has caused prices to rise, making batteries less affordable.
On the other hand, sodium, abundant in ocean water and sodium carbonate mining, is a much greener battery material. What’s more, this novel research has also made it one of the most powerful materials. To achieve a sodium battery with an energy density comparable to that of a lithium battery, the team needed to invent a new sodium battery architecture.
Innovations in Battery Architecture
Traditional batteries have an anode to store ions during charging. When the battery is used, ions flow from the anode through an electrolyte to the cathode, powering it in the process. Anodeless batteries eliminate this part and store ions by electrochemically depositing alkali metal directly onto the current collector. This method allows for higher cell voltage, lower cost, and higher energy density. But of course, it also presents unique challenges.
He Mr. Deysherexplained: “In any battery without an anode, there must be good contact between the electrolyte and the current collector. This is easy with a liquid electrolyte, as it can flow and wet all surfaces, but a solid electrolyte does not have this ability.«.
Liquid electrolytes, however, create a buildup that reduces the lifespan of batteries. But in the face of this challenge, the team took an innovative approach. Instead of an electrolyte surrounding the current collector, they developed a current collector that surrounds the electrolyte and uses aluminum powder – a solid material that can flow like a liquid. During battery assembly, the powder was densified under high pressure to form a solid current collector, maintaining liquid-like contact with the electrolyte, enabling a low-cost, high-efficiency cycle.
To end, Grayson Deysher He stated: “Solid-state sodium batteries are often considered a distant technology, but we hope this study will push the sodium field forward by showing that it can perform well, even better than the lithium version in some cases.«.
