High Pressure Pyrolysis Behavior Of Acetate Fiber And It Is Application In Lithium Ion Batteries

Cellulose acetate,as the main component of cigarette filter,has been widely used and showing an increasing trend year by year.However,as hundreds of trillion of cigarette filters are discarded every year,cigarette filters have become one of the major wastes that pollute and endanger people’s living environment.At present,the main treatment methods of cigarette filter waste are incineration and landfill,but the simple treatment way will cause certain harm to the ecological environment and people’s health.Therefore,how to recycle and reuse these cigarette filters and make them into materials with high additional value,such as carbon materials of various structures,may play a role in promoting the recycling and reuse of cigarette filters in the future.Up to now,most of the research methods of pyrolysis of cigarette filter waste are limited to atmospheric inert environment.Most of the products obtained are amorphous porous carbon materials and the morphology is relatively simple.However,from the 70 s of this century,the use of metastable synthetic technology represented by autogenous pressure method,hydrothermal method and supercritical CO2 method has provided new means and new ways for controlling material composition and microstructure in a wider range and optimizing material properties.Especially,as a thermodynamic dimension,pressure can make some thermodynamic processes difficult to be carried out under normal pressure under pressure.In this paper,the thermodynamic behavior of pyrolysis carbonization,such as temperature,pressure and heating rate,is studied by using the cigarette filter as the raw material and isostatic pressing sintering as the means.On this basis,the high pressure pyrolysis of the transition metal ions and cellulose acetate was studied.In addition,the pyrolytic carbon and its composite materials with different morphologies were tested as negative electrodes of lithium ion batteries.The results are as follows:(1)The effects of temperature,pressure and heating rate on the carbonization behavior of cigarette filter and the influence on the morphology and structure of carbon materials were studied.It is found that the increase of temperature and pressure helps to improve the graphitization degree of pyrolytic carbon,and the heating rate helps to control the morphology of pyrolytic carbon.Besides,these pyrolytic carbons are used as anode materials for lithium ion batteries,and their charge discharge performance,rate performance and impedance are studied.(2)In order to expand the application of pyrolytic carbon,we mixed the cigarette filter wastes with different content of cobalt(iron)ions and then carbonized under isostatic pressing.The structure and morphology of Co(Fe)/C were studied.Based on that,the electrochemical performance and lithium storage mechanism were analyzed.(3)In order to solve the problems of rapid decay of charge and discharge and low electrical conductivity when the Co(Fe)/C material is used as a negative electrode,the Co(Fe)/C material is coated with cyclohexane and carbonized under high pressure.The morphology and structure of Co(Fe)/C@C materials were studied,and the cycle efficiency and rate performance of lithium ion battery anodes were studied.