Details

Autor(en) / Beteiligte

• Liang, Tian
• Cao, Jian-Hua
• Liang, Wei-Hua
• Li, Quan
• He, Lei
• Wu, Da-Yong

Titel

Asymmetrically coated LAGP/PP/PVDF-HFP composite separator film and its effect on the improvement of NCM battery performance

Ist Teil von

• RSC advances, 2019-12, Vol.9 (7), p.41151-4116

Ort / Verlag

England: Royal Society of Chemistry

Erscheinungsjahr

2019

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) is an inorganic solid electrolyte with a Na superionic conductor (NASICON) structure that provides a channel for lithium ion transport. We coated LAGP particles on one side of a polypropylene (PP) separator film to improve the ionic conductivity of the separator, and water-dispersed polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) on the other side to reduce the interfacial resistance between the separator and the lithium metal anode. The results show that the LAGP/PP/PVDF-HFP separator has a high ionic conductivity (1.06 mS cm −1 ) at room temperature (PP separator: 0.70 mS cm −1 ), and an electrochemical window of 5.2 V ( vs. Li + /Li). The capacity retention of a NCM|LAGP/PP/PVDF-HFP|graphite full cell is 81.0% after 300 charge-discharge cycles at 0.2C. When used in a NCM|LAGP/PP/PVDF-HFP|Li half-cell system, the initial discharge capacity is 172.5 mA h g −1 at 0.2C, and the capacity retention is 83.2% after 300 cycles. More significantly, the surface of the Li anode is smooth and flat after 200 cycles. The interface resistance increased from 7 to 109 Ω after 100 cycles at 0.2C. This indicates that the synergistic effect of the asymmetric coated LAGP and PVDF-HFP is beneficial to inhibiting the growth of lithium dendrites in the battery and reduces the interface resistance. A LAGP/PP/PVDF-HFP double-sided asymmetric composite separator film was prepared to improve the battery performance in LIBs.