What the study found
The study found that a hierarchically solvating electrolyte helped lithium-metal batteries perform better at low temperatures. The electrolyte used a weakly coordinating ether, tetrahydropyran, a strongly coordinating ester, methyl propionate, lithium difluoro(oxalato)borate, and trifluorotoluene as a non-solvating diluent.
Why the authors say this matters
The authors conclude that these findings offer design principles for tailoring solvation chemistry to enable high-performance lithium-metal batteries in extreme environments. The study suggests this approach may help address the poor low-temperature performance caused by slow lithium-ion transport and high desolvation energy penalties.
What the researchers tested
The researchers engineered a hierarchically solvating electrolyte system and examined how its composition changed the local solvation structure and solid electrolyte interphase, or SEI, which is the layer that forms on the battery interface. They tested Li||Li symmetric cells and Li||LiCoO2 full cells at low temperatures, including -25°C and -45°C.
What worked and what didn't
The electrolyte produced an anion-enriched primary solvation sheath that lowered the activation energy needed for lithium-ion desolvation. The addition of trifluorotoluene promoted aggregate-dominant solvation, and the resulting SEI was described as compact, homogeneous, and mechanically balanced with organic and inorganic components. Li||Li symmetric cells cycled for over 6000 hours at -25°C, and Li||LiCoO2 full cells retained 85.5% of nominal room-temperature capacity at -25°C and 66.2% at -45°C after 400 stable cycles.
What to keep in mind
The available summary does not describe broader testing beyond the reported cell types and temperatures. It also does not provide comparison details for all possible electrolyte formulations, only the hierarchically tuned system described in the abstract.
Key points
- A hierarchically solvating electrolyte was designed for lithium-metal batteries.
- The system combined tetrahydropyran, methyl propionate, LiDFOB, and trifluorotoluene.
- The electrolyte formed an anion-enriched solvation sheath and a compact SEI.
- Li||Li symmetric cells cycled for over 6000 hours at -25°C.
- Li||LiCoO2 full cells kept 85.5% of nominal room-temperature capacity at -25°C and 66.2% at -45°C after 400 cycles.
Disclosure
- Research title:
- Low-temperature lithium batteries improved by hierarchical solvation chemistry
- 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
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