Preparation And Electrochemical Performance Of Petroleum Pitch Based Carbon Materials

With the rapid development of the social economy and the continuous improvement of people’s living standard,the fossil energy is gradually exhausted and the environmental pollution is becoming increasingly serious.Therefore,the clean and efficient utilization of energy has become the focus of the whole world.The development and development of energy storage system is imminent,and carbon materials play an irreplaceable role in energy conversion and storage.Carbon materials are widely used in the field of electrochemical energy storage because of its advantages such as large surface area,low density,good conductivity and stable chemical properties.Because of its rich source,low price and high carbon content,petroleum pitch has unique advantages as a carbon source for preparing carbon materials.In this work,petroleum pitch as a carbon source,SiO₂ as a template,the petroleum pitch based various carbon materials with different morphology and petroleum based carbon materials and composites were prepared by different methods.The application of petroleum pitch based carbon materials in lithium-sulfur batteries and supercapacitors were investigated.（1）The hollow carbon spheres were prepared by the chemical vapor deposition method,SiO₂ was used as the template,and the petroleum pitch was used as the carbon source.The carbon sulfur composite materials with sulfur content of 60%,65%and 75%were prepared,by using the hollow carbon sphere as the micro-limiter.among them the sample with sulfur content of 65%carbon sulfur composite material as a cathode material in lithium sulfur batteries,under the current density of 0.1 C,the initial discharge capacity was 1266.1 m Ah g^-1,and after 50 cycles,the capacity was stabled at 603.0 mAh g^-1.（2）The hierarchical porous carbon materials HPC derived from petroleum pitch with high specific surface area was synthesized by a simple one-step carbonization/activation method using silica nanospheres as the hard templates and the KOH as the activator.The obtained sample HPC_1:2:3 with a large specific surface area of 1952.6 m² g^-1,when used as an electrode material for supercapacitors,the HPC_1:2:3 exhibits a high specific capacitance of 341.0 F g^-1 at the current density of 1A g^-1,the specific capacitance can remain at 189.5 F g^-1 at a high current density of 50A g^-1,and outstanding cycling performance in the three-electrode system.（3）The NiMoO₄ and NiMoO₄/HPC composites were prepared by hydrothermal method and their phase and morphology were characterized.At the same time,the properties of NiMoO₄ and NiMoO₄/HPC composites as an electrode material for supercapicitors were investigated.The NiMo O₄/HPC composite exhibited high performance as an electrode material for supercapicitors,with the specific capacitance reached 1182.4 F g^-1 at a current density of 1 A g^-1,under the high current density of20 A g^-1,the capacitance is kept at 696.0 F g^-1,can retain 86.1%of initial capacitance after 1000 charge/discharge cycling.