Preparation Of Tellurium-Based Anode Materials For Lithium Ion Batteries And Their Lithium Storage Properties

With the rapid development of modern industry and technology,non-renewable resources on the earth have been continuously developed and utilized,and problems such as resource shortages and environmental pollution have become increasingly serious.People are urgently looking for green energy that can replace fossil fuels and can be recycled,including wind energy,tidal energy and solar energy.In the newgeneration of energy revolution,the emergence of lithium-ion batteries?LIBs?hasplayed an important role.The growing demand for portable electronic products,large electrical energy storage systems and electric vehicles has stimulated a strong interest in the development of rechargeable batteries with high energy and power density.There is huge potential in energy storage equipment.Tellurium is located in the main group of VI A,which has similar chemical properties to sulfur and selenium of the same group,but has higher electricaldensity.Tellurium and lithium can form Li₂Te,and its theoretical specific capacity is420 m Ah g^-1.These advantages make it have a higher specific capacity and a suitable potential platform.The main content of this paper is to nanometer tellurium-basedcompounds by hydrothermal method and telluride method,and to form composite materials by introducing different carbon materials,which are applied to anodematerials of lithium ion batteries.The main research contents and progress are as follows:One-dimensional Co Te/N-doped MOFs derived porous carbon nanofibers were successfully prepared based on electrospinning technology and telluride reaction.One-dimensional nanomaterials have many advantages when used as electrode materials.Hollow or porous structures can obtain large specific surface area andexcellent carrying capacity,and are widely used in catalysis,energy storage and other fields.The prepared Co Te/N doped porous carbon nanofibers have the characteristics of high specific surface area,multi-level pore structure and high nitrogen content.In particular,the transition metal telluride has unique semiconductor characteristics and high theoretical capacity;the porous carbon after PAN-MOF pyrolysis improves the conductivity of the composite material,and provides a good transmission channel for lithium ion transmission;The carbon cavity after pyrolysis of the internal MOFmaterial is beneficial to alleviate the volume change of cobalt telluride particles during charge and discharge,thereby improving the stability of the composite material;based on these advantages,Co Te/N doped porous carbon nanofibers areused as The anode materials of LIBs show excellent electrochemical performance.At a current density of 100 m A g^-1,after 200 cycles,its reversible capacity can maintain1020 m Ah g^-1,showing excellent electrochemical performance.Sb₂Te₃ nanosheets coated with two-dimensional porous carbon coating were successfully prepared based on hydrothermal and carbonization methods.Carbon coating is an effective method to eliminate the direct contact between the electrode material and the electrolyte during the cycle.The porous structure is an effective factor in alleviating the volume change of the battery during charging anddischarging.Here,based on simple hydrothermal and carbonization methods,we designed and prepared two-dimensional porous carbon coating-coated Sb₂Te₃nanosheets?Sb₂Te₃@C?.In a unique design,Sb₂Te₃ nanosheets are tightly wrapped by a uniform carbon layer,which can effectively relieve the structural stress of theelectrode material during charging and discharging and prevent the structure from powdering.As expected,through this optimized design,the Sb₂Te₃@C composite material showed good lithium storage performance.Under the current density of 100m A g^-1,the specific capacity after 200 cycles is 835 m Ah g^-1,and under the current density of 500 m A g^-1,the specific capacity after 500 cycles is 750 m Ah g^-1.