Synthesis Of Porous Carbon Materials And Their Application In The Lithium Ion Batteries

Compared with traditional batteries,lithium-ion batteries have the advantages of high energy density,long cycle life,small size,light weight,small self-discharge rate,no memory effect,wide application temperature range and environmentally friendliness etc.Currently lithium-ion batteries have broad application prospects in many fields such as 3 C electronic products?computers,communications and consumer electronics?,electric vehicles and static large-scale energy storage,etc.In the development of lithium-ion battery,electrode material is an important factor that restricts the performance and application of lithium-ion battery.So it is urgent to develop a new generation of lithium battery electrode material.Among the electrode materials,porous carbon materials have the advantages of excellent physicochemical stability,high specific surface area,high conductivity and controllable pores etc.And porous carbon materials are also easy to be doped with heteroatoms.What's more,the carbon skeleton has little volume expansion in the process of insertion and de-insertion of lithium-ion.Therefore,porous carbon materials have broad application prospect in the fields of lithium ion battery anode materials.There are various ways to prepare porous carbon materials.One of these is to use porous organic polymer as carbon source.Porous organic polymer derived porous carbon materials possess many positive features such as element designability,structural adjustability,ultra-high stability,high specific surface area and high carbon content and are widely used in the fields of gas adsorption,energy storage and lithium ion batteries etc.Based on the above-mentioned development and research status of anode materials,porous organic polymer and its derived porous carbon materials,the work of this paper includes:?1?Design and synthesis of tetrabromophenyl pentabenzene were described.A new kind of porous organic polymer with regular morphology were synthesized using tetrabromophenyl pentabenzene as building unit.The degree of polymerization of the synthesized materials were controlled by means of the solvent polarity of choice.One of these polymers,THF-porous organic polymer prepared in THF solvent,showed particle size of 1 um,specific surface area of 757.9 m2·g^-1 and weight loss ratio of 24.6 % at 800 ?.It is a new type of porous organic polymer with regular morphology,high specific surface area and thermal stability.?2?Porous carbon materials were prepared through carbonizations of porous organic polymer and were used as anode materials of lithium-ion battery.By studying the influence of carbonization temperature,material morphology and pore size on the electrochemical performance of porous carbon materials,we provide new ideas for the design of high performance lithium ion batteries anode materials.The porous carbon named THF-800 possesses good cycle stability and high rate performance.When used as anode in lithium-ion batteries,THF-800 can still retain a discharge capacity of 315 m Ah·g^-1 when charged-discharged at 200 m A·g^-1 for 300 cycles.When charged-discharged at a current density of 1 m A·g^-1,a discharge capacity of 237 m Ah·g^-1 is still retained after 1000 cycles.And the coulombic efficiency is still maintained close to 100% in the process of charging and discharging.It is proved that THF-800 is an electrode material with potential application value.