Integrated interface between composite electrolyte and cathode with low resistance enables ultra-long cycle-lifetime in solid-state lithium-metal batteries

• 作者: Zhuo Li Xin Guo
• 来源期刊: 中国科学：化学（英文版）
• 年，卷（期）: 2021,（4）
• 所属期刊栏目: ARTICLES
• 页码范围: 673-680
• 页数: 8页
• 语种: 英文

摘要

We report a three-dimensional (3D) nanofiber-reinforced solid composite electrolyte with a 3D Li+-conducting ceramic network of Li6.25Ga0.25La3Zr2O12 (LLZO) nanofibers.Benefiting from the 3D structure,the composite shows a high ionic conductivity of 3.2× 10-4 S cm-1 and Li-ion transference number of 0.32 at room temperature.The interfacial resistance between the composite solid electrolyte and cathode is mitigated by creating an integrated interfacial structure,in which the polyethylene oxide (PEO)-lithiumbis(trifluoromethylsulphonyl)imide (LiTFSI) binder and ionic liquids (ILs) form a viscoelastic interface.Therefore,intimate contact,low interfacial impedance,and fast ion-transport between the cathode and the solid electrolyte are simultaneously achieved.Solid-state lithium metal batteries with the LiFePO4 cathode deliver a superior capacity (158.0 mA h g-1) and significant capacity retention (90.4％ retention after 800 cycles) at 60 C.Moreover,the smooth and uniform Li surface after long-term cycling confirms the successful suppression of the dendrite formation.The integrated interfacial structure provides a solution to the interfacial problem and improves the cycling performance in solid-state Li-metal batteries.