Preparation And Properties Studies Of Si-based Anode Materials For Lithium-ion Battery

With the consumption of petroleum resource, a great increasingly of electric automobile were used, portable electronic equipments are much more popular among the whole world. So we have to research natures about the material of lithium cell.These natures are easy to carry, safety performance, low cost operation, environmentally friendly and so on. Silicon-based cathode composite was occured by many scholar for its capacity is about 4200 m Ah/g. Silicon resource is rich in nature. It has a lower cost when be used as materials. It has a big change in volume(>300) when charge-discharge. The distory of electrodematerials lead to department of electrodematerial and current collector, attenuation of volume and poor circulation. The surface of SEI will distory and reform with the change of volume. This can cause a consuming of Li-ion all the time. Lower the qualitative of recycle.In this paper first of all we study the qualitative of electrochemistry on pure silicon material. The first reversible capacity of micro silicon and silicon after the ball mill are respective 1517mAh/g and 1128.1m Ah/g, after recycle for 10 times discharge capacity down to 126 m Ah/gand190mAh/g, the qualitative of recycle is very bad. When we contrastive this two things we can find that si after the ball mill is better than the other one.This phenomenon shows that ball mill can increase the property of electrochemistry.Different proportion about si and c misture of composite cathode material. Make a connection about the high volume of Si and good stability on recycle of c. Analysis the feature and electrochemistry about different proportion of si and c composite material. We get a conclusion that when si:c=1:1, its proportion seems to be best.the first time to discharge capacity; charge capacity is 1130.7mAh/g; 817.2mAh/g. After five recycle left discharge volume is 434.6mAh/g. After 50 recycle the left discharge volume remain279mAh/g. It has a better discharge volume on the first time and it also has a better stabliity of recycle. But capacity loss still a big problem to solve.The best condition can be found by search different milling time, origin of carbon, the feature and property about electrochemistry on composite cathode electrode materials.Under the best condition, by ball milling twice use titanium dioxide, micrometer si and intermediate phase carbon microspheres, we can get composite cathode electrode material.We can have a further study on this material.