Abstract
The hierarchical carbon-coated lithium iron phosphate (LiFePO4) nano-grain microspheres are prepared by chemical co-precipitation method. The microstructure and cycling performance are compared for samples treated at 975K and 1025K. Transmission electron micrograph (TEM) analysis confirms the existence of ferric pyrophosphate phase of the general formula Fe4(P2O7)3. Reasons for the formation of the crystalline Fe4(P2O7)3 phase are intensively discussed. It is considered that a little amount of Fe4(P2O7)3 phase has no distinct detrimental effect on the cycling capacity of samples. Although there is a big decrease from 132 to 74.5mAh/g in discharge capacity at a current rate of 1C for the sample treated at 975K from 400 to 500 cycles. The capacities for the sample were observed to be recovered to its theoretical value in discharge at a current rate of 0.1C after 500 cycles. It is demonstrated that the degradation behavior for the sample treated at 975K is attributed to the increase of diffusion resistance of the lithium ions into the bulk of LiFePO4 electrode materials, which is not reported before in the literatures.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
