| Today,increasing environmental problems such as global warming and pollution provide a great impetus for reducing society’s dependence on fossil fuels.It is best to generate energy from renewable and sustainable resources for example the energy of wind and solar in the world.It is necessary for that efficient energy storage system.Among clean energy technologies,electrochemically efficient energy storage systems are considered to be the most feasible,environmentally friendly and sustainable.Lithium-ion batteries have received approval from the public.Energy storage devices such as these play an irreplaceable role in electronic products,electric vehicles,and smart power grids.More and more researchers will focus on how to improve the cycle stability and capacity of lithium-ion batteries.Among them,the research and development of new lithium-ion battery anode materials is important.one direction.Molybdenum disulfide is a typical layered structure with a larger theoretical interlayer distance than industrial graphite.The interlayer distance of 0.62 nm is conducive to the rapid insertion and extraction of ions during charge and discharge,and the four electron transfer reaction mechanism during charge and discharge It has a higher theoretical specific capacity(667 mA h g-1)than commercial graphite(372 mA h g-1),but key factors such as the irreversible volume expansion of the battery during charging and discharging and the inherently low electrical conductivity limit its Commercial application as electrode material.As we all know,carbon materials have better electrical conductivity,at the same time,they can better suppress the volume expansion of ions during extraction and insertion,and have better cycle stability.Therefore,we synthesize molybdenum disulfide and carbon composite materials to improve its cycle stability and capacity.Research from the following:1.Silicon oxide nanospheres prepared by the improved Stober method,with the help of the scanning electron micrograph of the sample,the silica nanospheres are uniform in size,have good dispersion,complete morphology,and the agglomeration phenomenon is not obvious.It can plays the role of template agent,and meet the expected requirements.2.The mixed hydrogel of graphene oxide(GO)prepared by biomass gelatin and Hummers method is used as the raw material,and the oxidized nano-silicon balls are used as the hard template to prepare the gelatin carbon sample.at the same time,the lithium storage performance of C/GO samples was studied.3.Using ammonium molybdate and thioacetamide as molybdenum source and sulfur source,gelatin carbon as carbon source,solvothermal synthesis of molybdenum disulfide and carbon composite materials,through XRD analysis of the sample,the carbon layer was successfully inserted into the molybdenum disulfide layer Between,resulting in a layer spacing of molybdenum disulfide of 0.99 nm,and through electrochemical performance analysis,the sample MoS2-1.5/C at a current density of 2A g-1,the specific capacity of 600 mA h g-1,sample MoS2-1.5/C compared to the other three carbon composite samples,showed better stability and relatively excellent specific capacity;our kinetic analysis of electrode materials,During the discharge process of electrode materials,the proportion of capacitance increased from 19%to 61%,this is because the sweep speed of the device increased from 0.1 mV s-1 to 1 mV s-1.which indicates that the pseudocapacitive charge storage accounts for part of the total capacity of the MoS2-1.5/C electrode.The excellent lithium ion storage performance of the MoS2-1.5/C electrode can be attributed to the unique hybrid three-dimensional structure and the more suitable pore size distribution.First,the large specific surface area of the material is conducive to full contact with the electrolyte,making it easy to enter the active site,thereby expanding the contact area of the electrode and the electrolyte for effective energy storage.Secondly,the hierarchical porous structure can reduce the transmission distance of lithium ions,thereby improving the electrode reaction kinetics.At the same time,the addition of gelatin carbon increases the conductivity,introduces heteroatoms and improves the defects of the material,which speeds up the reaction.By controlling the variable method,the solvothermal temperature and solvothermal time suitable for preparing MoS2/C composites were determined.4.Using plant calculation as the carbon source,hydrothermal synthesis of molybdenum disulfide and carbon composite materials.Through BET analysis,the sample MoS2/C-PA8ml pore structure has the best continuity,and the distribution of micropores,mesopores and macropores is good,showing Very good graded porous structure;in terms of electrical performance,the initial capacity of MoS2/C-PA8ml is 1252 mA h g-1,and after 160 cycles,the capacity is significantly higher than the other four MoS2/C composite materials;when the scan rate is from When 0.1mV s-1 is increased to 1.0 mV s-1,the capacitance contribution increases from 76.88%to 90.90%,which indicates that the pseudocapacitive charge storage accounts for a large part of the total capacity of the MoS2/C-PA8ml electrode... |
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