Building the homogeneous ionic interfaces and channels for high compatible composite PVDF/SiO2 solid electrolyte by grafting sulfonate betaine
Poor solid–solid interfacial compatibility has been a troubling challenge to the development of solid-state lithium metal batteries . For this purpose, inspired by mussel mimetic chemistry, the homogeneous ionic interfaces and channels between PVDF matrix and SiO 2 nanospheres were built by grafting sulfonate betaine (SB) on their surfaces via Schiff base reaction and ring opening reaction. Furthermore, the influence of SB-SiO 2 content on the structure, mechanical properties , thermal stability and electrochemical performances of the composite solid-state electrolyte was also studied. Desirably, Li + transference number and ionic conductivity of 8%SB-SiO 2 /SB-PVDF/LiTFSI electrolyte membrane were as high as 0.50 and 5.5 × 10 −5 S/cm, respectively, much higher than those of the counterparts in literatures. Uniform dispersion of SB-SiO 2 nanospheres in 8%SB-SiO 2 /SB-PVDF/LiTFSI electrolyte membrane built the homogeneous continuous ion channels, while the homogeneous structure of SB-PVDF and PVDF binder in the electrode also facilitated the interface compatibility of the membrane/electrode, and thus the synergistic effect improved the Li + transference number. The reversible specific capacity of LiFePO 4 // 8%SB-SiO 2 / SB-PVDF / LiTFSI // Li battery was 129.7 mAh/g at 1.0 C for 200 cycles, higher than those of other two electrolyte membranes, meanwhile, high-voltage LCO//8%SB-SiO 2 /SB-PVDF/LiTFSI//Li battery also exhibited good Li-storage performance, indicating high feasibility of 8%SB-SiO 2 /SB-PVDF/LiTFSI electrolyte membrane in solid-state lithium metal batteries .
危险品化学品经营许可证（带存储）