The Application Research Of Graphite Anode And Graphite Mixed With Silicon Anode In Li-Ion Batteries

Lithium ion batteries possess the advantages of good cycle performance, low self-discharge rate, high working voltage, large energy density, no memory effect and so on. It is widely used in the field of traffic, communication, space, energy storage. Anode materials have important influences on the performance of lithium ion batteries. Graphite can be used as anode materials of lithium ion batteries and has been widely used in industry. In this paper, we study the effects of coating carbon on graphite, silicon content and binder on the performance of silicon mixed with graphite anode, different graphite anode compaction density on the performance of battery.We found that rate performance, capacity and efficiency of the initial charge and discharge are improved by coating carbon on the surface of the graphite using chemical vapor deposition method. Cyclic voltammetry curves show that oxidation peak shift to low potential. Electrochemical impedance show the charge transfer impedance is reduced. Through researching silicon contend in graphite anode found that the initial charge and discharge capacity increase with silicon content increases, but the initial efficiency and cycle performance is reduced. The cohesive force of using LiPAA as good as the SBR, but the cycle performance of using the SBR is better. Through studying different graphite anode compaction density on the effects of battery performance, we find that cycle performance, rate performance, storage performance, internal resistance of battery is different with changing the compaction density. When compaction density of graphite anode is 1.7 g·cm-3, cycle performance and discharge performance of lithium ion are the best. With compaction density increasing, battery internal resistance and expansion of thickness will increase on 60?storage. Gas composition is consistent with different compaction density, the main gas are CO2.