Study On Characteristics And Electrochemical Properties Of Ginger Straw Carbon

At present,China’s energy consumption is increasing,accounting for more than 20%of the world’s overall.Fossil energy is not renewable and its exploitation is increasing,so traditional energy is gradually being depleted.With the increasingly prominent environmental problems,efficient,clean and sustainable development has become the mainstream of energy development in China and even in the world.Biomass is a very important renewable resource,in which biomass energy has the characteristics of green,clean,low carbon and so on,and it is the national"Thirteen-Five" period to achieve energy transformation and upgrad:ing of the important direction of development.In this study,porous carbon materials for super capacitor electrodes are prepared by using ginger straw from agroforestry waste,which provided a theoretical basis for high value and large-scale utilization of ginger straw.Now the utilization rate of ginger straw is not high,there are two reasons.First,ginger straw water content is high and difficult to deal with.Second,the current mode of utilization is rough and low returns.Based on the material characteristics of ginger straw itself,this paper presents a method for the preparation of ginger straw carbon by pyrolysis and activation in inert atmosphere.This method has the advantages of simple preparation process,low dosage of chemical reagent,energy saving and environmental protection.According to the thermal analysis curve of ginger straw in N2 atmosphere and the analysis of carbon yield at different temperatures,the carbon yield of ginger straw decreased with the increasing of carbonization temperature,and remained stable at about 30%after 700 ℃.The N content in ginger straw is relatively high,and the ginger straw carbon obtained after carbonization remained 3.06%.By XRF analysis of ginger straw,K content is relatively higher and Si content is relatively lower than other biomass.The K content in ginger straw is abundant,and it is a natural hole activator in the whole process of preparing ginger straw carbon.By microscopic characterization of ginger straw carbon prepared at various temperatures,the effect of carbonization temperature on the specific surface area and pore capacity of ginger straw carbon was investigated,and the specific surface area and pore capacity of ginger straw carbon were increased with the increase of carbonization temperature.The specific surface area and pore capacity of ginger straw carbon prepared at 1000 ℃ carbonization temperature are the highest,the ratio of table area to 960 m2 g-1,pore capacity reached 0.709 cm3 g-1.The carbon aperture of ginger straw prepared at various temperatures is mainly distributed at 0.5-0.8 nm and 2-4 nm.The ginger straw carbon prepared under 700 ℃ has more reasonable pore size structure distribution and better graphite,and the surface is rich in nitrogen and oxygen-containing functional groups.By comparing the microscopic characterization information of ginger straw carbon before and after pickling,it is very important to obtain pickling treatment for the preparation of super capacitor electrode with ginger straw carbon.The electrolyte of the prepared ginger straw carbon base electrode buckle battery is 6 M KOH solution.It is found that ginger straw carbon has excellent electrochemical properties,high capacitance,good magnification performance,high cycle stability,high energy density,low impedance and fast frequency response ability.The ginger straw carbon prepared under 700 ℃ shows optimum electrochemical properties,and in 0.1 A g-1,the mass ratio capacitance is as high as 274 F g-1.The prepared carbon electrode is increased from 0.1 A g-1 to 10 A g-1,and the capacitance retention rate is 80%,showing good magnification performance.When constant current charge and discharge cycle 6,000 times,the capacitance can still maintain 88%,indicating that there is a good cyclic stability.At the current density of 0.1 A g-1,the effective area capacitance is up to 38.1 μF cm-2.When the power density is 49.86 W kg-1,the energy density is 34.06 Wh kg-1.These excellent electrochemical properties are attributed to:abundant micro pores and reasonable pore structure distribution provide abundant accumulation space and transmission channel for charge,and rich nitrogen and oxygen-containing crown energy are abundant to ensure good wettability,and graphite reduces the resistance of the device.In summary,aiming at the problem that ginger straw,an agricultural and forestry waste,could not be treated to form pollution,based on the theme of waste utilization and energy conservation and environmental protection,as well as the research direction of biomass energy utilization,this paper uses pyrolysis one-step carbonization activation method to deal with Ginger Straw Porous Carbon material with excellent specific surface area,pore capacity aperture and electrochemical properties.It provides a feasible basis for the large-scale and high-value utilization of ginger straw.