Peking University has developed a new type of nano-cobalt porous carbon carrier lithium-sulfur battery material

The continuous advancement of science and technology has put forward higher requirements for lithium-ion battery technology, especially in the field of large-scale energy storage such as electric vehicles, and has put forward higher requirements for new-type lithium-ion batteries with higher energy density and lower prices. Among them, as a multi-electron reaction lithium-ion battery, the lithium sulfur battery has an energy density (2600Wh/kg) and price advantage far higher than the lithium iron phosphate and lithium cobalt oxide batteries currently on the market, so it has attracted widespread attention. However, there are a series of problems in the process of charging and discharging, such as poor conductivity of elemental sulfur, shuttle effect of intermediate polysulfides, and volume expansion during charging and discharging. At present, researchers have proposed a series of optimization strategies for the matrix material of the sulfur positive electrode, such as improving the conductivity of the sulfur positive electrode through porous carbon and improving the adsorption of polysulfides through nitrogen doping. However, the results obtained by various means are limited and cannot solve the problem fundamentally. Therefore, there is a need for a more effective cathode matrix material that combines multiple functions. Peking University has developed a new type of nano-cobalt porous carbon carrier lithium-sulfur battery material. A new type of lithium-sulfur battery material. The common responsibility of nanocrystals, as a new type of host material, the lithium battery with nitrogen-doped porous carbon cage is found through its excellent electrochemical performance characterization test, including XRD, SEM, TEM, XPS, and revealed through various means such as DFT The reasons for the performance clarify the positive effects of Co nanocrystals and polysulfide adsorption kinetics on the diffusion and conversion of lithium ions, and provide ideas for the preparation of new lithium battery cathode materials. The results were recently published in the well-known journal 'Advanced Energy Materials' (2020, 10 (9), 1903550, IFu003d24.884) in the field of energy materials. The novelty of this research lies in the fact that our group uses zNCO-MOF with high specific surface area to adsorb small glucose molecules. During the carbonization process, glucose is preferentially carbonized into a carbon frame with SP2 structure, and the metal cobalt is separated in the MOF cavity to improve conductivity. . At the same time, the appropriate amount of sulfur can make the active sulfur material be loaded in the carbon cage instead of the surface, so that the sulfur and the carbon cage skeleton maintain a strong interaction. The high dispersion of cobalt nanocrystals prepared by the team undertakes the loading of nitrogen-doped porous carbon cage polysulfide sulfur active raw materials and intermediates and multi-functional effects, including the improvement of electrical conductivity, high sulfur content, stress relief, and accelerated diffusion power of lithium ions They can ensure the high performance ratio and long cycle life of lithium-sulfur batteries. Peking University has developed a new type of nano-cobalt porous carbon carrier lithium-sulfur battery material. A new type of lithium-sulfur composite anode material has electrochemical performance. At the same time, a series of studies have shown that the highly dispersed Co nanocrystals carried in the framework can not only effectively promote lithium The diffusion of ions and the redox of polysulfides can further enhance the adsorption of polysulfides. This work provides a new reference for transition metals as high-performance catalysts for polysulfides in lithium-sulfur batteries. Disclaimer: The articles published on this site are all from the Internet and do not represent the views of this site. If there is any infringement, please contact to delete WeChat: Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact delete A: Negative failure of lithium-ion batteries and countermeasures