What the study found
The study found that a hierarchically solvating electrolyte can help lithium-metal batteries work better at low temperatures. The electrolyte used weakly coordinating ether, strongly coordinating ester, lithium difluoro(oxalato)borate, and a non-solvating diluent to change how lithium ions are solvated, which is the way solvent molecules surround and interact with the ions.
Why the authors say this matters
The authors conclude that these solvation-design principles may help tailor electrolytes for high-performance lithium-metal batteries in extreme environments. The study suggests this is relevant because conventional electrolytes suffer from slow lithium-ion transport and high desolvation energy penalties at low temperatures or high C-rates.
What the researchers tested
The researchers engineered an electrolyte system using tetrahydropyran (THP), methyl propionate (MP), lithium difluoro(oxalato)borate (LiDFOB), and trifluorotoluene (TFT). They examined how this composition affected solvation structure, solid electrolyte interphase (SEI, the layer that forms between the electrode and electrolyte), and battery cycling performance in Li||Li symmetric cells and Li||LiCoO2 full cells.
What worked and what didn't
The electrolyte formed an anion-enriched primary solvation sheath and reduced the activation energy needed for lithium-ion desolvation. The TFT diluent shifted the local solvation structure toward aggregate dominance and promoted a compact, homogeneous SEI with both organic and inorganic components, which helped preserve interfacial integrity during cycling at cryogenic temperatures. The reported performance included ultrastable cycling for over 6000 hours at −25°C in Li||Li symmetric cells, and 400 stable cycles in Li||LiCoO2 full cells, with 85.5% and 66.2% of nominal room-temperature capacity retained at −25°C and −45°C, respectively.
What to keep in mind
The summary does not provide detailed experimental conditions beyond the named cells, temperatures, and cycle counts. Limitations are not otherwise described in the available abstract.
Key points
- A hierarchically solvating electrolyte was designed from THP, MP, LiDFOB, and TFT.
- The electrolyte produced an anion-enriched primary solvation sheath and lowered lithium-ion desolvation energy.
- A compact, homogeneous SEI formed with both organic and inorganic components.
- Li||Li symmetric cells cycled for more than 6000 hours at −25°C.
- Li||LiCoO2 full cells showed 400 stable cycles and retained 85.5% capacity at −25°C and 66.2% at −45°C.
Disclosure
- Research title:
- Low-temperature lithium-metal batteries improved by hierarchical solvation
- Authors:
- Qichao Wang, Zhimin Cai, Yuhui Zhu, Wenji Yin, Sijiang HU, Yao Zhao, C. Zhang, Sen Xin, Tengfei Zhou
- Institutions:
- Beijing National Laboratory for Molecular Sciences, Beijing National Laboratory for Molecular Sciences, Beijing National Laboratory for Molecular Sciences, Guangxi Normal University, Guangxi Normal University, Hefei Institutes of Physical Science, Hefei Institutes of Physical Science, Hefei Institutes of Physical Science, Hefei Institutes of Physical Science, University of Science and Technology of China, University of Science and Technology of China, University of Science and Technology of China, University of Science and Technology of China
- Publication date:
- 2026-02-22
- OpenAlex record:
- View
- Image credit:
- Photo by Ayyeee Ayyeee on Pexels · Pexels License
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