A γ-Boehmite Nanowhiskers - Polyethylene Glycol 10000/Polyethylene Separator for Lithium-Ion Batteries

In this study, a gamma-boehmite (gamma-AlOOH) - PEG/polyethylene (PE) lithium-ion battery separator was fabricated using a dip-coating method, with gamma-AlOOH nanowhiskers being synthesized directly through a hydrothermal process,and polyethylene glycol 10000 (PEG-10000) was chosen for the first time as a dispersant for the gamma-AlOOH nanowhiskers in the PE coating slurry{Lee, 2014 #7}. Simultaneously, the membrane's performance was characterized, confirming the significant dispersion effect of PEG-10000, resulting in a porosity as high as 64 % in the AlOOH-PEG/PE, a substantial increase compared to the PE separator (40 %). The AlOOH-PEG/PE separator maintains its structural integrity even after a 0.5 h test at 200 degrees C, showcasing outstanding stability and significantly improved safety. Besides, the LIB half cells assembled with the PE/AlOOH-PEG separator exhibited remarkable performance, with a capacity of 73.9 % in power capability (at 5 C rate) and a 97.1 % discharge capacity retention rates in cycle performance (after 400 cycles, at 2 C rate). Furthermore, lithium iron phosphate (LiFePO4) batteries utilizing the AlOOH-PEG/PE separator demonstrated significantly enhanced cycling stability and rate capacity.