Effect of nano Al2O3 addition on cycling performance of poly(ether block amide) based solid-state lithium metal batteries.

A novel poly(ether block amide) (PEBA) based solid-state polymer electrolyte (SPE) was prepared using a casting method, in which 20wt% lithium (Li) bis-(trifluoromethanesulfonyl)imide (LiTFSI) and aluminum oxide (Al 2 O 3) nanoparticles were used as the Li salt and solid plasticizer, respectively. In the case of addition of 3wt% Al 2 O 3 nanoparticles, ion conductivity of the obtained PEBA 2533-20wt% LiTFSI-3wt% Al 2 O 3 SPE was 3.57 × 10 - 5 S cm - 1 at 25 °C. Furthermore, the Li symmetrical battery assembled with it showed excellent cycling stability (1000 h) at 0.1 mA cm - 2. While, the assembled all-solid-state Li/PEBA 2533-20% LiTFSI-3wt% Al 2 O 3/LiFePO 4 (areal capacity: 0.15 mAh cm - 2) battery maintained 94.9% of the maximal capacity (133.9 mAh g - 1@0.1 mA cm - 2) at 60 °C even after 650 cycles with a superior average coulombic efficiency (CE) of 99.84%. By using X-ray photoelectron spectroscope (XPS), self-aggregation layer (SAL) of polyamide 12 (PA12) of PEBA 2533 was discovered, which should contribute to promoting the robustness of lithium fluoride (LiF) enriched solidelectrolyte interphase (SEI) layer. In addition, it is considered that the state of interface between SPE and cathode should be the cause of voltage polarization of the full cell. [ABSTRACT FROM AUTHOR]