English

A TEM study of morphological and structural degradation phenomena in LiFePO4-CB cathodes

Materials Science 2016-12-07 v2

Abstract

LiFePO4-based cathodes suffer from various degradation mechanisms which influences the battery performance. In this paper morphological and structural degradation phenomena in laboratory cathodes made of LiFePO4 (LFP) mixed with carbon black (CB) in an 1 mol L-1 LiPF6 in EC:DMC (1:1 by weight) electrolyte are investigated by transmission electron microscopy (TEM) at various preparation, assembling, storage and cycling stages. High-resolution TEM (HRTEM) imaging shows that continuous SEI layers are formed on the LFP particles and that both storage and cycling affects the formation. Additionally loss of CB crystallinity, CB aggregation and agglomeration is observed. Charge-discharge curves and impedance spectra measured during cycling confirm that these degradation mechanisms reduce the cathode conductivity and capacity.

Keywords

Cite

@article{arxiv.1605.05477,
  title  = {A TEM study of morphological and structural degradation phenomena in LiFePO4-CB cathodes},
  author = {Duc-The Ngo and Roberto Scipioni and Søren Bredmose Simonsen and Peter Stanley Jørgensen and Søren Højgaard Jensen},
  journal= {arXiv preprint arXiv:1605.05477},
  year   = {2016}
}

Comments

5 figures, 2 table, journal article in International Journal of Energy Research, 2016