The Synthesis And Electrochemical Applications Of Biomass-derived Porous Carbon Materials

With the rapid development of economy,material energy and environmental pollution have become the two major challenges facing mankind,so looking for new energy and researching for new materials have attracted the attention of scientists.Porous carbon materials play an important role in energy storage and electrochemistry,because of their unique structural properties and excellent properties such as high specific area,thermal stability and high conductivity.In this paper,the preparation,characterization and properties of biomass-based porous carbon materials have been demonstrated.Through the use of cheap and easy to obtain waste biomass and its derivatives,using different preparation methods,obtained a variety of high specific surface,large pore volume of biomass-based porous functional carbon materials.We have studied their applications in lithium-ion batteries,lithium sulfur batteries and electrocatalytic.Firstly,we reported using cheap and readily available glucosamine and tin dichloride as raw materials to prepare the tin-based porous carbon(Sn/C)materials by simple hydrothermal carbonization and KOH chemical activation.The Sn/C composites possessed high specific surface area and large pore volume.At a current density of 100 mA g-1,the first discharge specific capacity is 1011 mAh g-1and remains 400 mAh g-1after 100 cycles.Secondly,nitrogen-doped 3D hierarchical porous carbon materials were synthesized from waste shrimp shell via a sustainable HTC and CO2 activation process.The obtained material possesses micro-meso-macroporous structure with SSA value of 1190 m2 g–1and pore volume of 0.52 cm3 g–1.The 3D hierarchical porous structure as well as the nitrogen functionalities enables the material as good matrix to hold sulfur,the sulfur content of the S@HTC-SS-CO2 is around 46 %.A reversible specific capacity of around 580 mAh g–1can still be preserved at the density of 1.0 C,which indicating a good rate capability of the S@HTC-SS-CO2 material.When the current density returned to 0.1 C,the cathode exhibited a high capacity of 870 mAh g-1.Thirdly,we have synthesized varies nitrogen-doped porous carbon materials with high specific surface area and large pore volume via a method of chemical activation.The structure and morphology of the materials were characterized.It was observed that a large number of macropores,mesopores and micropores have been observed.These structures and voids not only provide a large contact area for the ORR reaction,provide more active sites,but also provide a large number of effective channels for the immersion and electron transport of the electrolyte.Moreover,after high temperature carbonation and activation,the materials have rich graphitized carbon structure which is conducive to the ORR reaction.XPS measured the surface of the catalyst,the results show that the surface of the material has a lot of pyridine nitrogen and graphite nitrogen,the two nitrogen is considered as activity nitrogen state for ORR.