tailieunhanh - Electric Vehicles The Benefits and Barriers Part 12

Tham khảo tài liệu 'electric vehicles the benefits and barriers part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | LiFePO4 Cathode Material 209 that of LiFePC 4 adding too much of which would lead to low tap density and also influence volume energy density of the cathode. So a reasonable amount of it is preferred. Electric polymer organics PAn PPy PTh PPP and so on work with inorganic cathode has emerged as one measure to address problem. Such as adding polyaniline PAn into the C-LiFePC4 both the function of electronic conductive reagents and that of active materials are performed by adding it. The capacity of 87mAhg-1 can be performed by PAn at which can contribute to the specific capacity of the composites. Some other materials like metals Cu Ag Ni etc. can also be used to composite with semiconducting LiFePC4. TiC2-LiFePC4 C had higher electrochemical reactivity for lithium insertion and extraction than the un-doped LiFePC4. The initial discharge specific capacity of the 30-min coating TiC2-LiFePC4 C material was about 161mAhg-1 showing the potential of this material being used as a cathode material for Li-ion batteries. They decrease the charge transfer resistance and increase the surface electronic conductivity. Besides the Fe dissolution might be simultaneously overcome by coating the LiFePC4 particles with electrical conductive. Compositing with additive can not only enhance the electronic conductivity and the penetration with electrolyte but also restrain the grain growth and the dissolution of Fe2 Fe3 ions in the electrolyte. Above all the electrochemical performances can be improved through forming the composite materials. Doping LiFePC4 is a semiconductor with a band gap of which is determined by its structure. The electrons transport is restricted by the strong Fe-C bonds and the Li diffusion is limited by the Li-C bonds and one dimensional Li migration pathways. Coating LiFePC4 with conductive materials did not change the structure parameters and had no effect on altering the inherent conductivity of the lattice while doping ions into LiFePC4 can .