摘要： Self-terminated hyper-branched oligomers (STOBA) were coated and then melted on a Li(Ni 0.4 Co 0.2 Mn 0.4 )O 2 cathode to form a dense polymer film at high temperatures. The physical and structural changes of the polymer layer at different temperatures and charge conditions were investigated by nitrogen adsorption–desorption, X-ray photoelectron spectroscopy, resistance measurements, scanning electron microscopy, and solid-state 7 Li-NMR and 13 C-NMR spectroscopy in order to improve the understanding of the role of the STOBA layer in the enhancement of the safety mechanism of lithium ion batteries. The morphological change of the STOBA layer from the porous to nonporous state at the temperature of a thermal runaway of a battery was demonstrated. The change in the resistance values at high temperatures revealed that the STOBA coating is helpful for the prevention of internal short-circuiting and thermal runaway. Most importantly, the 7 Li-NMR results acquired at a very high spinning speed (50 kHz) allow the monitoring of the subtle changes in the local environments of the Li + ions and their interaction and mobility in the STOBA–cathode interface as functions of temperature and charge states. The combined characterization results improve the understanding of how the STOBA layer can contribute to the safety features of lithium ion batteries. 出版日期： 2014-01-01 出處： RSC advances, 2014-01, Vol.4 (99), p.56147-56155 資源來源： Royal Society of Chemistry 識別號： ISSN: 2046-2069 識別號： EISSN: 2046-2069 識別號： DOI: 10.1039/C4RA09220A
