Note: at the end of the paper, there is a brief introduction of the research team and an analysis of the research ideas in this paper
Solid electrolyte is regarded as the "Holy Grail" to solve the safety problem of lithium metal battery, especially organic / inorganic composite solid electrolyte, which is favored for its advantages of both inorganic solid electrolyte and polymer solid electrolyte. At present, the physical mixing method is mostly used in the construction of composite solid electrolyte. Although this method is simple and easy to operate, it can not solve the problem of poor interface compatibility between organic and inorganic materials. Even though researchers put forward many improved methods, such as reducing the particle size of inorganic materials, improving the arrangement order of fillers, etc., but the difference of conductivity between polymer and ceramic two phases in electrolyte And compatibility problems still restrict the performance of electrolyte, that is, the high conductivity of inorganic electrolyte can not be fully utilized, and the obvious phase separation will occur at high temperature, leading to electrolyte failure.
Recently, Zhang suojiang's team of the Institute of process research of the Chinese Academy of Sciences innovatively adopted in-situ coupling reaction method, using the commercialized silane coupling agent (3-chloropropyl) trimethoxysilane as the bridge agent, effectively combined the inorganic solid electrolyte li10gep2s12 with the polymer solid electrolyte PEO through chemical bond, and cleverly designed and prepared the flexible organic-inorganic composite solid with excellent performance electrolyte. It can be seen from the results of XPS that s-si bond is found in S 2p and Si 2p spectra, which confirms the bridging effect of silane coupling agent.
Figure 1. Preparation and physical properties of organic / inorganic composite solid electrolyte
Due to good interfacial compatibility, the electrolyte has high conductivity (room temperature > 0.9ms), good air stability and high lithium ion migration number (0.68). It is worth mentioning that the electrolyte has extremely excellent lithium metal compatibility. The lithium metal symmetrical battery with the above electrolyte can stably cycle for a long time (> 6700h) at room temperature. The assembled all solid state lithium metal battery shows high cycle stability and coulomb efficiency.
Figure 2. Cycle performance of lithium metal symmetrical battery
Figure 3. Cycle performance of lithium titanate and lithium iron phosphate all solid state lithium metal batteries
This achievement was recently published on advanced materials. The first author of this article is Pan Kecheng, a doctoral student of Tianjin University.
Original text (scan or long press QR code and go to the original page after identification): a flexible ceramic / polymer hybrid solid electrolyte for solid ‐ state lithium metal batteries Kecheng pan, LAN Zhang, * Weiwei Qian, Xiangkun Wu, Kun Dong, Haitao Zhang, suojiang Zhang * adv. mater., 2020, DOI: 10.1002/adma.202000399
Brief introduction of academician Zhang suojiang
Zhang suojiang, academician of the Chinese Academy of Sciences, director of the Institute of process engineering of the Chinese Academy of Sciences, President of the College of chemical engineering of the Chinese Academy of Sciences, vice president of the Chinese chemical society, and director of the ionic liquid Professional Committee of the Chinese chemical society. Winner of National Science Fund for Distinguished Young Scholars, chief scientist of "973", national candidate of "one million talents project in the new century", member of Royal Society of chemistry.
Mainly engaged in the research of ionic liquid, green process, system integration, etc. Related research results have published more than 350 SCI papers in important academic journals such as JACS, angel Chem, chem rev, chem SOC rev, AIChE J, etc., with more than 12000 citations, h-index 60, 8 Chinese and English books, and more than 120 authorized invention patents. Served as editor in chief of green energy and environment (GEE), Journal of process engineering, editorial board member of IEC res, green Chem and other international journals. He founded the national ionic liquid conference and Asia Pacific ionic liquid conference, organized academic conferences and served as the chairman / Vice Chairman of the conference, and was invited to make conferences or theme invitation reports for many times. It has won the second prize of National Natural Science, science and technology promotion development award of Chinese Academy of Sciences, Hou Debang chemical science and technology achievement award and many other awards.
https://www.x-mol.com/university/faculty/23692
Analysis of scientific research ideas
Q: How did the idea of the study come about? A: As mentioned above, the problem of poor internal interface compatibility of composite solid electrolyte has always existed, and the improvement methods reported at present are mostly physical methods with little effect. Since physical methods can not solve this problem well, we naturally think of chemical methods. Considering the reaction functional groups of organic and inorganic electrolytes and the similarity between hydrogen bond and lithium bond, we found silane coupling agent which can play a bridging role, and finally prepared composite solid electrolyte membrane with excellent internal interface compatibility.
Q: What are the challenges and difficulties in the process of experimental research? A： Compared with the physical mixing method, the chemical method has more strict requirements on the amount of raw materials, reaction time, treatment sequence, etc. In the process of the experiment, we find problems, consult materials, discuss with teachers, solve problems, and then find new problems In this way, after N cycles, the high-performance electrolyte in this paper was finally obtained. Therefore, I would like to encourage my friends who haven't got their own satisfactory results. Don't rush to give up to change the topic in case of difficulties. The topic we are doing is handed over to us after careful consideration by the tutor. We should try our best to overcome the difficulties with gratitude. Our strength is limited. We should communicate and discuss with you more, and believe that we will get a satisfactory conclusion in the end Fruit.
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