ACS Nano: Li Qilin research group of Shanghai Silicate Institute has made important progress in the research of high specific energy organic magnesium battery

The application of large-scale energy storage device represented by smart grid puts forward higher requirements for cycle life, power density, cost and safety of energy storage battery The room temperature secondary magnesium battery is a kind of electrochemical energy storage system with magnesium as the negative electrode It has the advantages of rich reserves, low cost (the price of magnesium is less than 5% of the price of lithium metal), large volume specific capacity (3833 MAH / cm 3), no dendrite formation during the electrochemical cycle, and the theoretical reduction potential of magnesium ion is only 0.6 higher than that of lithium ion The energy density of Mg based battery is the same as that of Li-ion battery as long as the suitable anode structure frame is used Moreover, the stable reversible deposition / stripping of magnesium ion is helpful to restrain the negative extreme volume expansion, reduce the consumption of electrolyte, and significantly improve the cycle life and power density of Mg based batteries Therefore, magnesium battery can meet the requirements of the next generation energy storage system without sacrificing the energy density However, the slow intralattice migration of magnesium ions and the low theoretical capacity of inorganic framework still limit the wide application of magnesium batteries Lithium magnesium double salt electrolyte system can realize the activation of positive and extreme dynamics by the dominant lithium ion (instead of magnesium ion) embedded in the positive lattice At the same time, it does not sacrifice the stability of negative extreme cycle process of magnesium metal, avoids the disadvantage of poor dynamic performance of magnesium ion, and greatly expands the selection range of positive materials for magnesium battery Recently, a team led by Li Qilin, researcher of Shanghai Silicate Research Institute, Chinese Academy of Sciences, proposed a kind of multi electron reactive organic magnesium battery activated by double salt electrolyte Its positive electrode uses green and renewable rose red acid salt (such as Na 2c6o 6) The results were published in ACS Nano, a famous journal of American Chemical Society (DOI: 10.1021 / acsnano 7b09177) The nanostructured organic system with high density carbonyl (C = O) as the redox reaction site can achieve a reversible capacity (three electron transfer) of up to 350-400 MAH / g the redox graphene oxide (RGO) wiring can further achieve a high rate of electrochemical performance Its capacity can still be maintained at 200 and 175 at 2.5 A / g (5C) and 5 A / g (10c) current density, respectively MAH / g, high power performance also benefits from the formation of dendrite free magnesium anode under the condition of high current and long cycle This excellent performance benefits from the high intrinsic diffusion coefficient (10-12-10-11cm 2 / s) and pseudocapacitance contribution of more than 60% of lithium in na2c6o6 The stronger non lithium pinning effect (realized by na-o-c and mg-o-c) can inhibit the exfoliation of c6o6 layer in the grain and achieve at least 600 charge discharge cycles The energy density of the positive active material of the organic magnesium battery can exceed 500 WH / kg, and it can tolerate the power density of more than 4000 w / kg, which exceeds the level of high potential embedded positive material based on inorganic structure The team has long been committed to the research on the improvement strategy of Mg based battery dynamics The research work has been funded and supported by the national key research and development program, the National Natural Science Foundation of China, the 100 person program of the Chinese Academy of Sciences and the Shanghai 1000 person program