Li Fujun research team of Nankai University: the latest breakthrough in the field of negative materials for potassium ion batteries

The development of renewable energy and smart grid requires more and more low-cost and large-scale energy storage system Due to the abundant Potassium Resources and high working voltage, potassium ion battery has a bright future in large-scale energy storage system However, large-scale K + (1.38 μ) makes the development of suitable electrode materials face severe challenges Recently, Li Fujun's research team of Nankai University has made another breakthrough in the field of anode materials for potassium ion batteries (DOI: 10.1002/anie.201801389) introduction to research group of researcher Li Fujun Li Fujun's research team was founded in September 2015 At present, there are 1 researcher, 4 doctoral students and 11 master's students in the research team Relying on the Key Laboratory of the Ministry of education of advanced energy materials chemistry of Nankai University and the "porous micro nano structure and high efficiency chemical power" team of the national 2011 Tianjin chemical industry collaborative innovation center (chief scientist, academician Chen Jun), the research team is mainly engaged in new energy materials Preparation of materials and development and application of new battery system Li Fujun, a distinguished researcher and doctoral supervisor of the school of chemistry of Nankai University, was selected as one of the "youth thousand talents" program of Tianjin and "one hundred youth discipline leaders" of Nankai University Researcher Li Fujun received his master's degree and doctor's degree from Nankai University (tutor, academician Chen Jun) and Hong Kong University respectively He successively engaged in postdoctoral research at Tokyo University and AIST in Japan In 2015, he joined the school of chemistry of Nankai University and joined the team of "micro nano structure and efficient chemical power supply" So far, he has published nearly 30 papers in the international famous journals such as NAT Commun., angel Chem Int ed., adv mater., energy energy energy SCI., nano lett., adv energymater., adv funct Mater., etc as the first or corresponding author Invited as reviewer of multiple journals Cutting edge scientific research achievements: the latest breakthrough in the field of negative electrode materials for potassium ion batteries K has higher activity than Li and Na, and it is easy to form dendrites in the process of battery circulation, which brings serious security risks The oxidation / reduction potential of the anode material of the ideal potassium ion battery should be between 0.3-1.5v, which can not only avoid the formation of potassium dendrites but also avoid the loss of the output voltage of the whole battery Therefore, it is very important to find a suitable anode material for potassium ion batteries (a) charge discharge curve of potassium ion battery (b) cycle stability of potassium ion battery (c) schematic diagram of potassium ion battery (d) Ragone curve of Bi / / Pb full battery (source: angel Chem Int.ed, Doi: 10.1002/anie.201801389) the traditional conversion reaction type negative electrode has serious charge / discharge overpotential, and is unstable in the charge / discharge process Small organic molecules, such as potassium terephthalate, exhibit a suitable charge discharge platform and reversible capacity of 220 MAH · g-1, but are limited by slow dynamics and poor conductivity Alloy anode usually has a safe reaction potential and a large reversible capacity, but in the traditional ester electrolyte, the sharp volume change of this kind of material during charging / discharging is easy to cause expansion and pulverization, and the capacity decay is fast In response to this problem, Li Fujun's research team from the school of chemistry, Nankai University recently made great progress in the negative electrode materials by using the synergistic effect of commercial bismuth metal and glycol dimethyl ether electrolyte to greatly improve the comprehensive performance of potassium ion batteries They found that bismuth undergoes three two-phase reactions in the process of potassium storage, namely Bi A kind of KBi 2 A kind of K 3 Bi 2 A kind of K3bi shows an obvious charge discharge platform and reversible capacity of about 400 MAH · g-1 In the process of charge and discharge, bismuth will gradually change into a stable three-dimensional network porous structure in the ether electrolyte, while in the ester electrolyte, bismuth will rapidly expand and powder The first principle calculation shows that the formation of the porous structure is caused by the strong chemical adsorption between glycol dimethyl ether and bismuth, which induces the dislocation of the surface atoms of bismuth This kind of three-dimensional network porous structure can not only hold the volume change of bismuth in the process of circulation, but also facilitate the infiltration of electrolyte and the rapid transmission of electrons and ions In addition, ether electrolyte can form a stable, high conductivity K + solid electrolyte film on the bismuth surface, which greatly improves the coulomb efficiency and stability of the battery Under the synergistic action of ether electrolyte, bismuth can release about 371.4 MAH · g-1 specific capacity at 800 Ma · g-1 current density, and the capacity retention rate is 86.9% after 300 cycles The whole battery assembled with Prussian blue anode also shows high energy density and excellent cycle stability of 108 wh · kg-1 Relevant work was recently published in angelw Chem Int.ed (DOI: 10.1002 / anie 201801389) The work was supported by the National Natural Science Foundation of China and the Ministry of science and technology of China Nowadays, people and scientific research have been paid more and more attention in the economic life China has ushered in the "node of science and technology explosion" Behind the progress of science and technology is the work of countless scientists In the field of chemistry, in the context of the pursuit of innovation driven, international cooperation has been strengthened, the influence of Returned Scholars in the field of R & D has become increasingly prominent, and many excellent research groups have emerged in China For this reason, CBG information adopts the 1 + X reporting mechanism CBG information, chembeango app, chembeango official microblog, CBG wechat subscription number and other platforms jointly launch the column of "people and scientific research", approach the domestic representative research group, pay attention to their research, listen to their stories, record their demeanor, and explore their scientific research spirit.