Recently, the team of Professor You Ya from ISMSE published a research paper titled "Entropy-Driven Solvation toward Low-Temperature Sodium-Ion Batteries with Temperature-Adaptive Feature" in the top international materials journal "Advanced Materials"(Adv. Mater. 2023, 2301817), which caused high attention in the field. "Nature Review Materials" magazine selected this result as Research Highlights and reported it under the title "A battery electrolyte adapts to the cold", which fully affirmed the temperature-adaptive electrolyte design concept.

Figure 1 Highlights from Nature Reviews Materials

Currently existing carbonate-based commercial electrolytes cannot meet most of the requirements for extreme secondary energy storage batteries, such as supporting higher voltage (≥4.5V), wide temperature range (±60°C) charge and discharge, and being non-flammable. sexual ability. The development of alkali metal ion batteries under such extreme conditions has great scientific significance for aerospace and defense, national economy and people's livelihood, polar exploration and other fields. However, under extreme low temperature conditions and high temperature and high pressure conditions, the application of high specific energy and high safety batteries still cannot be achieved.

The study broadens the use temperature of the electrolyte by adjusting the solvation entropy in strongly solvating (SS) and weak solvating (WS) mixed solvents. The solvation structure of the electrolyte can spontaneously transform at low temperatures to avoid the precipitation of salts. It gives the electrolyte the characteristics of temperature adaptability. Research results show that this temperature-adaptive electrolyte ensures the excellent low-temperature performance of hard carbon | Na_2/3Ni_1/4Cu_1/12Mn_2/3O₂full batteries, with a capacity retention rate of 90.6% after 400 cycles at -40°C. This result illustrates the importance of entropy adjustment and provides a new perspective for designing low-temperature electrolytes.

Figure 2 Design strategies for low-temperature electrolytes

In the field of secondary batteries under extreme conditions, Professor You Ya's research team achieved the use of low-freezing point cyclic ethers in low-temperature electrolytes by introducing a water scavenger in the early stage (Angew. Chem. Int. Ed., 2023, 62, e202300238 ). In view of the problem that lithium-ion battery cathode materials are prone to oxygen evolution at high voltages and cause battery safety and electrochemical performance attenuation, the design of solvation structures is used to build a phosphate-rich interface to solve the dual problems of electrochemical performance and safety at high voltages. Hidden dangers (Adv. Mater., 2023, 35, 2210966). In order to provide design ideas for the safety of lithium battery electrolytes and standardize the safety assessment of electrolytes, we cooperated with Professor Li Kaiyuan of School of Safety Science and Emergency Management to propose the evaluation standards for flame-retardant electrolytes and the classification of flame-retardant/non-flammable electrolytes. Design Guidelines (ACS Energy Lett., 2023, 8, 836). The above research provides theoretical and technical support for further broadening battery application fields and breaking through battery application limits.

Website links for the paper：

（1）https://doi.org/10.1002/adma.202210966

（2）https://doi.org/10.1021/acsenergylett.2c02683

（3）https://doi.org/10.1002/adma.202301817

（4）https://onlinelibrary.wiley.com/doi/10.1002/anie.202300238

Website link for the report：

https://www.nature.com/articles/s41578-023-00580-y

You Ya is a professor at the International School of Materials Science and Engineering of Wuhan University of Technology, mainly engaging in the research and development of key materials and devices for secondary batteries under extreme conditions. She has won the Hubei May 4th Youth Medal, Hubei Positive and Kind Youth Award, Outstanding Achievement Award for China's Emerging Scientific and Technological Figures, and Young Scientist of China. So far, she has published more than 60 academic papers, with a total of more than 7,000 citations, and an H-index of 40. She has hosted projects such as the National Natural Science Foundation of China, Yibin City's "Open bidding for selecting the best candidates" science and technology projects, and industrial projects. You Ya serves as deputy secretary of the Youth League Committee of Wuhan University of Technology (temporary position), director of the Materials Department of the International School of Materials Science and Engineering, editorial board member of ACS Applied Materials & Interfaces, executive director of the Electrical and Electronics Engineers Electric Power and Energy Association, etc.

Editor:Xie Xiaoqin

Reviewer:Yan Kui