Preparation&Lithium Ion Batteries Electrochemical Performance Research Of Silicon Nano Anode Materials

With the processing of economic globalization and the continuous growth in demand for clean energy,Searching for new energy storing device has been a hot topic in the area of new energy related fields.Lithium-ion battery is deemed to be one of best comprehensive energy storage systems due to its small volume,large capacity,light weigh,no pollution,high energy density,low self-discharge rate,And it has been applied to various electric products such as mobile phone,video camera,laptop,electronic toys and electronic vehicle.At present,commercial lithium-ion battery mainly use graphite as cathode material,and it has good circulation performance,but the theoretical energy desity is a little bit low as the 160 Wh kg-1,it cannot meet people's need for power battery.For the sake of futher improving the energy density of Lithium-ion battery,the development of anode and cathode materials with high ratios capacity is the key.Silicon anode material is one of the most promising high-capacity anode materials because of its high theoretical specific capacity(4200 mAh g-1)and lower lithium ion potential(<0.5 V).However,silicon has a large volume expansion and shirinkage effect after many cycles of charge and discharge,it lead to a poor electrochemical performance.But we know that nano-silicon can reduce the problem of fracture.Hererin,we developed two facile,scalable and low cost synthesis strategies to fabricate nano-silicon with different structures,the synthsis of 2D silicon nanosheets and Si/C nanoparticles,we have chracterized their structure and test electrochemical performance.The detailed contents are as follows:utilizing the unique combination of the water-soluble NaCl particles as the sacrificial template and the hydrolyzed tetraethyl orthosilicate as the silica source,and assisting with the magnesium reduction method to prepare Si nanosheets,importanly,the obtained Si nanosheets have a larger area up to 10 um2.And we charactrized the structure of Si nanosheets by SEM,TEM,Raman,XRD and et.al.Through combining with reduced graphene oxides(rGO),the Si nanosheets@rGO composite electrode exhibits excellent electrochemical performances.The commercial fly ash particles were treat by ball milling,and evenly dispersed it in the supersaturated glucose solution and carbonized at high temperature in argon,and assiting with the magnesium reduction method to fabricate the Si/C nanoparticles.Charctrizing it through various tools,and the Si/C nanoparticles exhibit better electrochemical performance.