Breakthrough advances sodium-based battery design
By stabilizing a metastable form of sodium solid electrolyte, a new technique creates all-solid-state sodium batteries that retain performance down to subzero temperatures
University of Chicago
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New research from the lab of UChicago Pritzker School of Molecular Engineering Liew Family Professor of Molecular Engineering Y. Shirley Meng raises the benchmark for sodium-based all-solid-state batteries as an alternative to lithium-based batteries.
view moreCredit: UChicago Pritzker School of Molecular Engineering / Jason Smith
All-solid-state batteries are safe, powerful ways to power EVs and electronics and store electricity from the energy grid, but the lithium used to build them is rare, expensive and can be environmentally devastating to extract.
Sodium is an inexpensive, plentiful, less-destructive alternative, but the all-solid-state batteries they create currently don’t work as well at room temperature.
“It’s not a matter of sodium versus lithium. We need both. When we think about tomorrow’s energy storage solutions, we should imagine the same gigafactory can produce products based on both lithium and sodium chemistries,” said Y. Shirley Meng, Liew Family Professor in Molecular Engineering at the UChicago Pritzker School of Molecular Engineering (UChicago PME). “This new research gets us closer to that ultimate goal while advancing basic science along the way.”
A paper from Meng’s lab, published this week in Joule, helps rectify that problem. Their research raises the benchmark for sodium-based all-solid-state batteries, demonstrating thick cathodes that retain performance at room temperature down to subzero conditions.
The research helps put sodium on a more equal playing field with lithium for electrochemical performance, said first author Sam Oh of the A*STAR Institute of Materials Research and Engineering in Singapore, a visiting scholar at Meng’s Laboratory for Energy Storage and Conversion during the research.
How they accomplished that goal represents an advance in pure science.
“The breakthrough that we have is that we are actually stabilizing a metastable structure that has not been reported,” Oh said. “This metastable structure of sodium hydridoborate has a very high ionic conductivity, at least one order of magnitude higher than the one reported in the literature, and three to four orders of magnitude higher than the precursor itself.”
Established technique, new field
The team heated a metastable form of sodium hydridoborate up to the point it starts to crystalize, then rapidly cooled it to kinetically stabilize the crystal structure. It’s a well-established technique, but one that has not previously been applied to solid electrolytes, Oh said.
That familiarity could, down the road, help turn this lab innovation into a real-world product.
“Since this technique is established, we are better able to scale up in future,” Oh said. “If you are proposing something new or if there’s a need to change or establish processes, then industry will be more reluctant to accept it.”
Pairing that metastable phase with a O3-type cathode that has been coated with a chloride-based solid electrolyte can create thick, high-areal-loading cathodes that puts this new design beyond previous sodium batteries. Unlike design strategies with a thin cathode, this thick cathode would pack less of the inactive materials and more cathode “meat.”
“The thicker the cathode is, the theoretical energy density of the battery – the amount of energy being held within a specific area – improves,” Oh said.
The current research advances sodium as a viable alternative for batteries, a vital step to combat the rarity and environmental damage of lithium. It’s one of many steps ahead.
“It's still a long journey, but what we have done with this research will help open up this opportunity,” Oh said.
Citation: “Metastable sodium closo-hydridoborates for all-solid-state batteries with thick cathodes,” Oh et al. Joule, Sept. 16, 2025. DOI: 10.1016/j.joule.2025.102130
Journal
Joule
Article Title
Metastable sodium closo-hydridoborates for all-solid-state batteries with thick cathodes
Article Publication Date
16-Sep-2025
Researcher develop the first hydride ion prototype battery
Dalian Institute of Chemical Physics, Chinese Academy Sciences
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Schematic diagram of the first hydride ion prototype battery
view moreCredit: DICP
Hydride ion (H⁻), with their low mass and high redox potential, are considered promising charge carriers for next-generation electrochemical devices. However, the lack of efficient electrolyte with fast hydride ion conductivity, thermal stability, and electrode compatibility has hindered their practical applications.
In a study published in Nature, Prof. CHEN Ping’s group from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a novel core–shell hydride ion electrolyte, and constructed the first rechargeable hydride ion prototype battery.
Using a heterojunction-inspired design, researchers synthesized a novel core–shell composite hydride, 3CeH3@BaH2, where a thin BaH2 shell encapsulates CeH3. This structure leverages the high hydride ion conductivity of CeH3 and the stability of BaH2, enabling fast hydride ion conduction at room temperature along with high thermal and electrochemical stability.
Furthermore, researchers constructed a CeH2|3CeH3@BaH2|NaAlH4 all-solid-state hydride ion prototype battery battery using NaAlH4, a classical hydrogen storage material, as the cathode active component. Positive electrode of the battery delivered an initial discharge capacity of 984 mAh/g at room temperature and retained 402 mAh/g after 20 cycles.
In a stacked configuration, the operating voltage reached 1.9 V, powering a yellow light-emitting diode lamp, which was a compelling example for practical applications.
By adopting hydrogen as the charge carrier, this technology avoided dendrite formation, paving the way for safe, efficient, and sustainable energy storage. With the tunable properties of hydride-based materials, hydride ion batteries hold immense potential for clean energy storage and conversion.
Researcher develop the first hydride ion prototype battery [VIDEO]Journal
Nature
Method of Research
Commentary/editorial
Subject of Research
Not applicable
Article Title
A room temperature rechargeable all-solid-state hydride ion battery
Article Publication Date
17-Sep-2025
