Title :
Vacancy formation and attractive interaction between vacancies and Chlorine in Chlorine-doped LiFePO4
Author :
Dinh, Van An ; Nara, Jun ; Ohno, Tetsufumi
Author_Institution :
Global Res. Center for Environ. & Energy based on Nanomater. Sci. (GREEN), Nat. Inst. for Mater. Sci. (NIMS), Tsukuba, Japan
Abstract :
The influence of Chlorine doping on the electrochemical properties of the cathode material LiFePO4 for rechargeable Li ion batteries is investigated. The optimized crystal structure, electronic structure and chemical bonds between ions are calculated. The most preferable substitution site of Chlorine is estimated. Vacancy formation is evaluated via the calculation of Li ion vacancy formation energy at all Li sites of 1 × 2 × 2 supercell. It is found that Chlorine atom substituting for Oxygen causes a decrease of Li vacancy formation energy, resulting in the enhanced diffusion rate of Li ions. However, the attractive interaction between Li vacancy and Chlorine can lead to the blocking effect on some diffusion paths, therefore the choice of the doping way and amount of Chlorine dopants is very sensitive.
Keywords :
Fermi level; bonds (chemical); crystal structure; diffusion; doping; electrochemical analysis; electrochemical electrodes; iron compounds; lithium compounds; secondary cells; vacancies (crystal); Fermi level; Li ion vacancy formation energy; Li16Fe16P16O63Cl; blocking effect; cathode material; chemical bonds; chlorine atom; chlorine dopants amount; chlorine doping; crystal structure; diffusion paths; diffusion rate; electrochemical properties; electronic structure; oxygen atom; rechargeable Li ion batteries; supercell; Nanotechnology;
Conference_Titel :
Nanotechnology Materials and Devices Conference (NMDC), 2011 IEEE
Conference_Location :
Jeju
Print_ISBN :
978-1-4577-2139-7
DOI :
10.1109/NMDC.2011.6155337
