Research on Sodium Ion Energy Storage Battery Progressed
Developing cost-efficient and high-performance electrochemical energy storage material and technology will greatly facilitate the large-scale application of energy storage battery technology in power system and overcome the bottleneck in smart grid development. Prof. Jiangkai and researcher Wang Kangli from High Magnetic Field Engineering & State Key Lab of Electrochemical Technology on Energy Storage have been devoted to the research on the new energy storage battery. On October 2nd, their latest research achievement, the paper titled Sulfur-doped Disordered Carbon as High Performance Anode Material for Sodium Ion Batteries was published in Energy & Environmental Science ,the top periodical under the Royal Society of Chemistry, UK.
With the same working mechanism as Lithium ion battery, sodium ion battery has a promising prospect of application in large-scale energy storage for the wide sources of sodium and its low cost. However the radius of sodium ion is much larger than that of lithium ion so it’s very difficult to develop appropriate sodium doped electrode. For example, graphite anode can be widely used in commercialized Lithium ion battery while not in sodium ion battery. However disordered carbon like MCMB, carbon fiber and pyrolytic carbon only have a capacity of 100-250 mAh g-1 as the anode material of sodium ion battery, much lower than the required capacity. With the small molecule NTCDA and elementary substance sulfur as raw material, the lab obtained the disordered carbon doped with sulfur through high temperature pyrolysis and for the first time used it as the anode material of sodium ion battery. The material boasts a reversible capacity as high as 516 516 mAh g-1 and a cycling stability rate as high as 85.9%, the anode material with the best comprehensive performance till now. The research on the material’s electrochemical reaction mechanism proved that sulfur as the doped atom could provide partial capacity （~200 mAh g-1）through its own oxidation-reduction reaction. Besides, compared with the porous carbon not doped with sulfur, there is an obvious improvement of in the layer spacing （002 crystal face）, specific surface area and conductivity, which further proved that sulfur doping could effectively activate carbon materials and the coordination between sulfur and carbon can greatly improve the performance of carbon material in sodium ion battery. The research pinpointed the new direction to develop sodium ion battery with high capacity, high efficiency and high cycling stability.
It's introduced that New Key Lab of Electrochemical Technology on Energy Storage has also made new headway in other aspects of their research on the electrode materials of sodium ion battery. For example, it synthesized the titanium-oxygen-sodium ion battery with high reversible capability, excellent cycling stability and rate capability through molten salt electrochemical approach. It synthesized the Sb2Se3/C composite sodium ion battery alloy anode material with high reversible capability and excellent cycling stability; in terms of the organic electrode material of sodium ion battery, it synthesized the cathode material doped with macromolecular compound, which can not only change the charge-discharge mechanism of ordinary macro molecular compound cathode material to sodium ion deintercalation from PF6- doping but also solve the problem that most macromolecular compounds don't contain sodium, which provided new insights in developing clean and inexpensive macromolecular compound electrode materials.
New Key Lab of Electrochemical Technology on Energy Storage was co-established and supported by High Magnetic Field engineering- New Technology State Key Lab and School of Material Science & Engineering，HUST. It’s committed to the research on new energy materials including the basic and application research on low-cost liquid metal battery, sodium ion battery and lithium-sulfur battery.