CHEN Yongzhen, LI Hualing, SONG Wenji, et al. Regeneration of spent LiFePO4cathode materials using solid state method and electrochemical performance[J]. CIESC Journal, 2018, (12): 5316-5325. DOI: 10.11949/j.issn.0438-1157.20180319.
DOI:
CHEN Yongzhen, LI Hualing, SONG Wenji, et al. Regeneration of spent LiFePO4cathode materials using solid state method and electrochemical performance[J]. CIESC Journal, 2018, (12): 5316-5325. DOI: 10.11949/j.issn.0438-1157.20180319.DOI:
Regeneration of spent LiFePO4cathode materials using solid state method and electrochemical performance
The recycled cathode material was obtained after removing the binder of the scrap electrode by heat treatment. The regenerated materials were obtained by high temperature solid state method that adding different proportions of Li
Fe
and P element sources to the recycled material on the basis of quantitative analysis. In this paper
the influence of impurities on regenerated materials was investigated and the optimal proportion of regenerative reaction materials was obtained. The results showed that the Fe2P impurity occurred during the regeneration process. The diffraction characteristic peak of the Fe2P phase gradually declined with the increase of Li
Fe and P element sources. The presence of Fe2P phase decreases the specific capacity of the sample due to the low content of LiFePO4 active material. The morphology of regenerated materials tends to become densification as the proportion of Li
Fe and P element sources increases. The fine and close microstructure decreases the capacity and cycle performance of regenerated materials. The initial specific discharge capacities of the recycled material
stoichiometric regenerated material and excess element sources regenerated material were 103.4
115.8 and 134.0 mA·h·g-1
respectively. Compared with that of the recycled material
the initial specific discharge capacity of the two regenerated materials was improved by 11.99% and 29.59%
respectively. The discharge capacities of the above three materials after 50 cycles are 100.9