| 摘要： |
In general, solid polymer electrolyte suffers from relatively low ionic conductivity and inferior oxidation stability. Herein, these issues can be effectively addressed by a supramolecular strategy based on the intermolecular interaction between a novel amorphous comb polymer of poly[propylene oxide-co-2-(2-methoxyethoxy)ethyl glycidyl ether] [P(PO/EM)] and highly fluorinated anion based lithium salt of lithium trifluoro(perfluoro-tertbutyloxyl)borate (LiTFPFB). The supramolecular solid state polymer electrolyte exhibits superior lithium ion transference number (0.59). It is noted that this polymer electrolyte presents enlarged electrochemical window up to 4.6 V (vs. Li/Li+ at 70 degrees C), which is resulted from the powerful supramolecular interaction between polymer skeleton and lithium salt. The supramolecular interaction was confirmed by Fourier transform infrared spectroscopy (FT-IR) analysis, solid state nuclear magnetic resonance (NMR) spectroscopy, stripping and self-healing tests. More bracingly, high voltage LiFe0.2Mn0.8PO4/Li cell based on this polymer electrolyte exhibits improved cycling performance (capacity retention is 88.7% after 100 cycles at 0.1C). Meanwhile, this well-designed electrolyte endows LiFe0.2Mn0.8PO4/Li cell pouch cell excellent safety characteristic even under deformation and truncation procedures. This supramolecular strategy paves a new way for boosting high energy density all solid state lithium metal batteries. |
