Wenhao Ren,Yafang Zhang,Ruixin Lv,Shiyuan Guo,Wenjia Wu,Yong Liu,Jingtao Wang
Solid-state polymer electrolytes , featuring excellent processability and flexibility, have received considerable attentions. However, the inherent low ionic conductivity , especially at subzero temperatures, limits their widespread application. Herein, quasi-solid polymer electrolyte (QSPE) with high low-temperature ionic conduction ability is prepared by in-situ ring-opening polymerization of 1,3-Dioxlane with fluoroethylene carbonate (FEC) as plasticizer . The in-situ polymerization imparts good interface contact between QSPE and electrode. The addition of FEC improves the chain mobility and facilitates the dissociation of LiTFSI, giving QSPE a remarkable ionic conductivity and Li + transference number (2.4 × 10 −5 S cm −1 at −60 °C and 0.55 at −20 ° C), two orders of magnitude and 2.3 times higher than those of liquid electrolyte , respectively. As a result, the Li/QSPE/Li cell without significant polarization is obtained, which can operate at 0.2 mA cm −2 and 0 °C for 850 h. Moreover, the LiFePO 4 /Li cell exhibits excellent cycling stability at 0.2 C and 0 °C: its capacity remains 125.2 mAh g −1 at 400th cycle, exceeding most polymer electrolytes . Even at −20 °C, a discharge capacity of 73.3 mAh g −1 is obtained at 100th cycle under 0.2 C.
Dexuan Pei,Ziying Liu,Rui Ma,Shuo Huang,Shuen Hou,Min Liu,Guozhong Cao,Hongyun Jin
Composite polymer electrolytes (CPEs) have shown extraordinary promise for use in all-solid-state lithium metal batteries (LMBs) because of their tunable merits in ionic conductivity and mechanical flexibility. Their practical application is however hindered by the poor interface stability and the uncontrollable Li dendrite formation. Addressing these two issues, we report an in-situ formed Li-Al-O interface layer between CPEs and Li metal anode by introducing Al 2 O 3 nanoparticles in CPEs. X-ray photoelectron spectroscopy results indicated that the CPE-Al 2 O 3 could slowly release Al atoms which react with Li metal to form the current Li-Al-O interface layer. We highlight that the Li-Al-O interface layer can stabilize lithium deposition/stripping over 1400 h in lithium symmetric batteries, and afford an impressive cycle life of 300 cycles in LiFePO 4 -Li batteries with almost no capacity loss. The present findings demonstrate that in-situ constructing a slow-release Li-Al-O interface layer is an easy and effective approach to stabilize the solid electrolyte interface and suppress the Li dendrites growth. Furthermore, the obtained batteries show excellent cycling stability, indicating the strategy with in-situ formed CPEs shed light on improving the processability of fabrication of high-performance electrolytes.
危险品化学品经营许可证（带存储）