Dual-Interlayers Constructed by Ti3c2tx/Ionic Liquid Enhance Efficient Performance for Solid Garnet Batteriesinterests

Li6.4La3Zr1.4Ta0.6O12 (LLZTO) solid garnet-type electrolyte has been widely reported due to its outstanding safety and electrochemical stability. However, the inherent rigidity and brittleness of LLZTO lead to poor contact with anode/cathode and the operation failure of full cells. Herein, the dual-interlayers are constructed as the fast interfacial ion-migration channel by using Ti3C2Tx (Mxene, Tx is -O, -OH, -F), polyvinylidene fluoride (PVDF) and ionic liquid (IL, LiTFSI in [BMIM][TFSI]), which promote the intimating contact between LLZTO and anode/cathode, and suppress Li-dendrite growth. Notably, the terminating group (Tx) in Ti3C2Tx can enhance the interaction between the Mxene and polymer chain, resulting in the decreasing crystallinity of the polymer and increasing interlayer ion conductivity. Moreover, the multi-layer structure of Ti3C2Tx can induce uniform ion flux and construct the shielding of Li-dendrite. Meanwhile, IL can wet the cathode to promote intimate interface contact and be decomposed into some inorganic compounds (such as LiN3, LiF and Li2Sx), resulting in reduced interfacial resistance and fast Li-ion transportation. Consequently, in the prepared Li-symmetric cell, the interfacial resistance on the anode side plunges to 33.1 Ω cm-2, and stably maintains over 1000 h without short circuit at 0.05 mA cm-2. The full cell of Li|LiFePO4 delivers a high initial capacity of 158.52 mAh g−1 and outstanding retention of 90.18 % after 100 cycles at 60 °C and 0.2 C. Our work provides an efficient strategy to design dual-interlayers between LLZTO and anode/cathode for the interfacial modification of high-performance solid garnet batteries.