Study On Preparation And Electrochemical Performance Of Cellulose-based Composite Negative Materials

Graphite negative,which is a commonly used negative material at this stage in commercial lithium batteries,has problems such as low specific capacity and poor cycle performance.In this paper,a new type of negative electrode material is prepared firstly,selecting Fe2O3 with high specific capacity as the electrode active material,combined with the porous carbon cellulose aerogel and the high conductivity graphene.And then the electrochemical performance of this negative material is explored.The paper mainly carried out four aspects of research,namely the preparation and characterization of cellulose carbon aerogel substrate,graphene/mesoporous Fe2O3 particles,cellulose carbon aerogel substrate negative material and the negative electrochemical testing of materials.In the experiment,the samples prepared at various stages were subjected to FTIR,XRD,Raman,SEM,TEM,N2 adsorption and desorption and rheology tests.The research results show that:(1)When cellulose carbon aerogel is used as the substrate of the composite negative material,the preparation process has a significant impact on its electrochemical performance.The electrochemical performance of the cellulose carbon aerogel substrate negative material prepared by the cyclic freezing method is better than that of the heating method.(2)The negative electrode material prepared by the cyclic freezing method has a first-round discharge specific capacity up to 900 mAh/g.At a charge-discharge rate of 0.6 C,after 100 cycles of charge-discharge,the specific capacity remains at 410 mAh/g,and the capacity stabilizes at 75%of the initial capacity.(3)The composite negative electrode material prepared in this research has better long-cycle performance and higher cycle specific capacity,and can be used in the negative electrode materials of small electronic devices commonly used in daily life.