A Recyclable Inert Inorganic Framework Assisted Solid-State Electrolyte for Long-Life Aluminum Ion Batteries

The environmentally friendly and high-safety aluminum-ion batteries (AIBs) have attracted intense interest, but the extensive use of expensive EMIC-AlCl(3 )electrolyte, strong moisture sensitivity, and severe corrosion of the Al anode limit their commercial application. Herein, we develop a solid-state electrolyte (F-SSAF) with an AlF3 inert inorganic framework as the solid diluent, EMIC-AlCl3 as the electrolyte, and FEC@EMIC-AlCl3 (FIL) as the interface additive for solid-state AIBs (SSAIBs). The dissociation of Al2Cl7 (-) (AlCl3-AlCl4 -) into AlCl4 (-) is promoted by AlF3, which can facilitate the migration rate of AlCl4 (-) active ions and simultaneously mitigate the corrosion of the Al anode. The introduction of an AlF3 inert inorganic framework can also reduce the dosage of expensive EMIC-AlCl3 and alleviate the moisture sensitivity of EMIC-AlCl3. The FIL is introduced into the surfaces of both anode and cathode, thus in situ forming F-rich SEI and CEI films. The F-SSAF enables Al|F-SSAF|Al symmetric cells to achieve ultralong stable deposition and dissolution of Al up to 4000 h, and Al|F-SSAF|C full cells to achieve an unprecedented long cycle life of 10000 cycles with an average Coulombic efficiency of >99%. In addition, up to 80% of the AlF3 inert inorganic framework can be recycled. This work provides a simple yet substantial strategy for low-cost, long-life, and high-safety SSAIBs.