recently, the team of researchers from the institute of physics of the Chinese academy of sciences and zhongke sea sodium Hu yongsheng proposed a polymerizable flame retardant electrolyte system (Polymerizable non-flammable electrolyte)(Polynonflyte, or PNE).
the team achieved no thermal runaway at 300 ℃ in the 3.5 Ah grade steel shell cylindrical sodium ion battery core, successfully passed the acupuncture test, the battery core did not smoke, catch fire or explode, and successfully realized no thermal runaway of the ampere-hour sodium ion battery!
The study was published in Nature Energy under the title “Thermal runaway-free ampere-hour-level Na-ion battery via polymerizable non-flammable electrolyte”.
Safety is the most important requirement in the development of battery technology, and ensuring that the battery does not have thermal runaway under thermal abuse is the primary prerequisite for its practical application. In recent years, the flame retardant electrolyte represented by phosphate ester has played a key role in battery safety due to its non-flammable characteristics, and has become one of the hot spots in the research of high safety lithium/sodium ion batteries. However, the simple non-flammable characteristics can not guarantee that the battery will not run away thermally, and the key lies in how to solve the problem of side reactions at the interface between the positive and negative electrodes and the crosstalk between the positive and negative electrodes at high temperatures.
At present, most of the flame retardant electrolytes need to use high salt/local high salt or fluoride system, which is costly and has poor compatibility with hard carbon negative electrodes, which greatly limits its practical application. Especially for sodium-ion batteries, most of the research mainly focuses on verifying the non-flammable characteristics of the flame-retardant electrolyte itself, and lacks the electrochemical and thermal safety demonstration in Ah-level cells. Therefore, the development of both low-cost and interface stability of flame-retardant electrolyte, in the ampere-class core to ensure excellent electrochemical performance while achieving no thermal runaway operation, is one of the key challenges to be overcome in the development of high-safety sodium ion batteries.
based on the above challenges, Hu yongsheng’s research team used NaBF4 as the main salt and NaPF6 as the auxiliary interface regulator to construct a double salt system, which solved the compatibility problem of hard carbon negative electrode and optimized the electrode-electrolyte interface. At the same time, based on triethyl phosphate (TEP), thermally induced polymerization is realized on the basis of non-flammability, and can be rapidly solidified at high temperature to form a partition layer, shielding the mechanical/chemical crosstalk between the positive and negative poles, completely blocking the thermal runaway reaction of the battery, and successfully realizing the non-thermal runaway of the sodium ion battery. The electrolyte also shows excellent electrochemical performance, even in 4.3V, 211 Wh/kg (based on the weight of the cell) high voltage, high specific energy Ah soft package cell still maintain stable operation and through the needle test.
[introduction of Hu yongsheng and his team]
Hu yongsheng is a researcher at the institute of physics, Chinese academy of sciences, founder of zhongke sea sodium, executive director of China silicate society, top ten representatives of China association for science and technology, and representative of Changzhou municipal people’s congress. He has successively undertaken projects such as the 863 Innovation Team of the Ministry of Science and Technology, the National Outstanding/Outstanding Youth Science Fund, and the National Key R & D Program. In 2024, he was selected as a 333 high-level talent (first level) in Jiangsu Province. Since 2011, he has been mainly engaged in basic research on the application of sodium ion batteries, and has published more than 300 papers in Science, Nature Energy and other academic journals. WoS has been cited more than 61000 times and H-factor 134. We have applied for more than 150 Chinese invention patents and have authorized more than 80 patents (including a number of patents in the United States, Japan and the European Union). Currently, he is senior editor of ACS Energy Letters magazine, co-author of Sodium-Ion Battery Science and Technology and Sodium-Ion Batteries. Won the first prize of the 2022 Beijing Natural Science Award, the first prize of the 2025 Guangxi Autonomous Region Technology Invention Award, the “2023 Energy Storage Person of the Year” in the 7th International Energy Storage Innovation Competition, the 2022 Chinese Academy of Sciences University Leading Goose Silver Award, The 14th China Youth Science and Technology Award, the Tajima Prize of the International Electrochemical Society, etc.
the sodium ion battery technology developed by Hu yongsheng’s team was selected into the “top ten breakthrough technologies in 2026” of MIT science and technology review, the company was selected into its list of “10 climate science and technology companies worthy of attention” and “50 smart companies” in 2025, the top ten scientific and technological innovations in the energy industry of the national energy administration in 2024, the major scientific and technological achievements of Zhongguancun forum in 2023 and the first energy electronics industry of the Ministry of industry the gold medal in the finals of the innovation competition, the “technology innovation award” in the first national advanced energy storage technology innovation challenge in 2022, the “2022 energy storage technology innovation model TOP10” in the 6th international energy storage innovation competition, the “endeavor new era” theme achievement exhibition in 2022, the “2019 energy storage technology innovation model TOP10” and “jury award” in the 3rd international energy storage innovation competition, the 9th special prize for scientific and technological achievements transformation of Beijing branch of Chinese academy, 2020 Science and Technology Innovation and Entrepreneurship Competition TOP10, 2020 Zhongguancun International Frontier Science and Technology Innovation Competition Finals Runner-up, the developed megawatt sodium-ion battery energy storage system was selected as the first (set) major technical equipment of the National Energy Administration twice (2021 and 2024). Lead the development of the first domestic sodium ion battery group standard “sodium ion battery general specification.”
