Preparation Of High Performance Anodes By High Performance Bearing Tin Oxide For Porous Carbon Materials

Large-scale mining and use of traditional fossil fuels not only cause a large amount of pollution to the environment,but also cause a series of climate issues,such as global warming.Therefore,more and more people join the new energy research.Among them,the development of lithium-ion batteries has become the focus of new energy research.Currently,commercial anode material for lithium-ion batteries is graphite.However,the specific capacity of the graphite anode is lower(372m Ah·g^-1),with high attenuation,and cannot meet people’s needs.In numerous anode materials,tin-based oxides are received by high theoretical capacity(782 m Ah·g^-1)and low lithium insertion potentials.However,the tin oxide is restricted to agglomeration and powder by volume expansion defects.At the same time,low energy density and interface instability hinder the actual application of tin oxide during cycle.In view of the above problems,this paper starts from the"carbon skeleton method",preparing porous carbon material to carry tin oxide,thereby effectively inhibiting the volume expansion effect of tin oxide,increasing the electrode discharge ratio capacity,reducing the first irreversible capacity,improved Culen efficiency,improve the electrochemical properties of tin oxide lithium ion batteries.First,this researcher is subjected to the biopolycarbon material（BC）from the common waste cotton.The biotechnical material（BC）retains complete plant fibers,and can effectively store electrolyte,improve lithium ion transmission rate,thereby ensuring electron conductivity.However,the biological carbon materials（BC）is the one-dimensional carbon material,which is generally in the load capacity of tin oxide.To solve this problem,the researchers use the difference between the melting point and the boiling point between different materials.The surface of tin oxide surface is uniformly manganese oxide as a buffer layer,not only to a degree to alleviate the volume expansion effect.Further,when the SnO₂-Mn@BC composite material is prepared,Mn-C bond can be formed with biological carbon materials（BC）.The Mn-C is effective to enhance the carrying capacity of biological carbon materials（BC）on tin oxide.The SnO₂-Mn@BC battery has excellent electrochemical properties.The current density is 100m A·g^-1,the discharge capacity of the SnO₂-Mn@BC battery first and hundreds cycles is 22021.2 and 768.14m Ah·g^-1,coulomb efficiency is as high as 99.25%.Further,a nitric porous carbon（N-HPC）materials was prepared by one-step carbonization method,which was used as a carrier of tin oxide.The N-HPC material is rich in pore structure and can effectively carry tin oxide.Not only that,but the doping of nitrogen in N-HPC material shortens the diffusion distance of lithium,providing a large number of lithium ion（Li⁺）storage centers.In addition,N-HPC materials have more defects and active centers to produce excellent conductivity.The tin oxide content of N-HPC material was 1.83mg/cm².When the current density is100m A·g^-1,the first discharge ratio of the electrode reaches 1774.45m Ah·g^-1.After100 cycles,the discharge capacity remains at 1492.92m Ah·g^-1,and the coulomb efficiency is 99.78%.According to the electrochemical test results,the SnO₂/N-HPC electrode has good comparable capacity and Kulen efficiency.Finally,the cobalt-rich porous carbon（PC（CO））material is prepared as a carrier of tin oxide by one-step carbonization method.The PC（CO）material is not only highly loaded with tin oxide but also the cobalt oxide in the material can effectively reduce the generation of LiO₂,but consumes the certain lithium ion.Therefore,the addition of lithium fluoride can be added,not only the lithium ion consumed when the cobalt oxide（CoO_X）is consumed during electrochemical reaction,but also reduces the charge transfer resistance（Rct）and the stability of the SEI film.The SnO₂-PC（Co）/LiF material was prepared as a high performance anode material by a simple hydrotherm synthesis method.After calculation,tin oxide in the SnO₂-PC（Co）/LiF electrode is as high as 1.51 mg/cm².After testing,the SnO₂-PC（Co）/LiF electrode electrochemical is excellent,the discharge ratio capacity after the first and 100 cycles of the electrode is 1653.63 and 1070.68 m Ah·g^-1(current density of 100 m A·g^-1),the utilization rate of active substances is as high as 93.14%,and Kurun is maintained at 99.81%.