Study On Capacitance Of Carbon Aerogel Composites Derived From Domestic Wastes

In today's society,environmental problems caused by the sharp increase in energy demand and the burning of traditional fossil fuels are constantly emerging.As a new type of green energy storage device,supercapacitors can effectively solve the two major problems of environment and energy.Supercapacitors have the advantages of high energy density and power density,long cycling stability,fast charge/discharge rate,and environmentally friendly,which can make up for the defects of traditional capacitors and batteries.Electrode material is the fundamental factor affecting the performance of supercapacitors.The development of electrode materials with higher specific capacitance and lower cost has become the focus of research.Layered metal double hydroxide has a high specific capacitance,and domestic waste-derived carbon materials have low cost,high stability,and high electrical conductivity.Combining the two is expected to obtain high-performance,low-cost electrode materials for supercapacitors.At present,the increase in urban population will lead to a rapid increase in domestic waste.The post-processing of domestic waste,including corrupt fruits and vegetables,is difficult,and leachate will cause a large number of microorganisms to multiply and cause secondary pollution to the environment.This paper proposes the preparation of carbon aerogels?CS?using rotten fruits and microorganisms as raw materials to compensate for the problems of poor stability and conductivity of the nickel-cobalt layered double hydroxide?Ni-CoLDH?.The preparation of composite electrode materials can effectively solve environmental problems and energy crisis.The main contents and results of this paper are as follows:?1?Two dimensional?2D?Ni-CoLDH and three dimensional?3D?hollow Ni-CoLDH were prepared by coprecipitation method and sacrificial template method,respectively.The results show that 3D Ni-CoLDH₃ has higher specific surface area,pore structure,and excellent properties.At a current density of 1 A/g,the specific capacitance of 3D Ni-CoLDH₃ is as high as 933.42 F/g,and the rate performance is 63.29%.After 1000 cycles of testing at a current density of 5 A/g,the specific capacitance retention of 3D Ni-CoLDH₃ is 85.29%.?2?Carbonized aerogels were prepared from rotten fruits?rotten apples?by high temperature carbonization and combined with 3D Ni-CoLDH.The effects of different carbonization temperatures on rotten apple-derived carbon aerogels?RA-CS?were discussed.When the carbonization temperature was 800°C,the RA-CS₈₀₀ exhibited a porous nanosphere network structure with a specific capacitance of 276.11 F/g,a rate performance of 65%,and a cycle stability of 98%.When the content of RA-CS₈₀₀ is 3 mg,the RA-CS₈₀₀/3D Ni-CoLDH₃-3composite electrode material has high specific capacitance?970.60 F/g?,high conductivity and excellent stability?89.01%?.The performance of RA-CS₈₀₀/3D Ni-CoLDH₃-3 is higher than that of 3D Ni-CoLDH₃.?3?Carbon aerogels were prepared by freeze drying and carbonization?800 degrees Celsius?using microorganism?Rhodopseudomonas palustris?as raw materials,and their 3D Ni-CoLDH₃ was compounded.The results show that Fe₂P exists in porous microbial-derived carbon aerogel?M-CS?carbon aerogels and exhibit excellent cycle stability?99.49%?and good electrical conductivity.When the content of M-CS₈₀₀ is 8 mg,M-CS₈₀₀/3D Ni-CoLDH₃-8 has high specific capacitance?1876.82 F/g?,good rate performance,excellent stability?90.13%?,and high Electrical conductivity,which will be better than 3D Ni-CoLDH₃.