Study On Sodium Storage Application Of Pitch Based Mesoporous Carbon Materials

As a low-cost energy storage device,sodium ion batteries?SIBs?has great development and application potential.Currently,amorphous carbon materials are one of the most widely studied anode materials for SIBs.The problems of low sodium storage capacity and poor cycle performance are the bottlenecks for the development of amorphous carbon materials for SIBs.In order to solve these problems,this paper proposes to prepare mesoporous carbon materials using pitch as raw materials by surface-anchoring-template-carbonization method.Furthermore,the methods of S-doping and compounding with metal compounds are used to improve the energy storage performance of mesoporous carbon.A series of amorphous mesoporous carbon-based materials with good sodium storage performance were obtained.The specific research contents are as follows:?1?Study on the preparation and sodium storage performance of pitch-based mesoporous carbon materials.Amorphous mesoporous carbon materials were constructed using pitch by surface-anchoring-template-carbonization method.The effects of different carbonization temperatures on the morphology,pore structure and electrochemical performance of the materials were investigated.The prepared mesoporous carbon materials exhibited a good electrochemical performance.Its capacity remained at 169 m Ah g^-1after 200 cycles at a current density of 0.2 C.?2?Study on the preparation and sodium storage performance of S-doped mesoporous carbon materials.Mixing the mesoporous carbon material and sulfur powder to achieve S-doing.The carbon layer spacing of the mesoporous carbon materials increased from 0.405 to 0.46 nm after S-doping.The sodium storage performance of the carbon material is greatly improved.Its capacity can be maintained at 263.8 m Ah g^-1after200 cycles at a current density of 0.2 C.The enlargement of the mesoporous carbon layer spacing is conducive to the transport of Na⁺,and increases the sodium storage utilization of the carbon atoms inside the material.In addition,S-doping can increase the defect degree of carbon materials and enhance the adsorption capacity of Na⁺.?3?Study on the preparation and sodium storage performance of ZnS/mesoporous carbon composites.To solve the problem of low specific capacity of carbon-based materials,the composite of mesoporous carbon and ZnS was realized.On the one hand,the conversion reaction mechanism of ZnS was used to improve the specific capacity of the material;On the other hand,mesoporous carbon was used to improve the structural stability of ZnS.As a result,the specific capacity of the optimized ZnS/mesoporous carbon composite can be maintained at283.4 m Ah g^-1after 200 cycles at a current density of 0.2 C.