Add an Extra Layer to Bring Lithium‐Ions Out of Disorder for Longevity of the Solid Full Batteries

Abstract In the current era of rapid development in the new energy vehicle industry, graphite (Gr) has gained significant attention as the primary anode material for commercial lithium‐ion batteries due to its exceptional reversibility in lithium‐ion insertion/extraction and abundant availability. In this study, a multifunctional ferroelectric Bi 12 TiO 20 @C (BIT@C) modified interlayer between Gr and polymer electrolyte (PE) is fabricated. This approach established a channel and homogeneous ion‐conducting network that facilitated lithium‐ion intercalation into Gr at the interface while suppressing erratic lithium precipitation, thereby stabilizing the structure of Gr. The uniform electric field generated by BIT intercalation enabled homogeneous intercalation/deintercalation of lithium ions, effectively preventing the structural collapse of the Gr anode. Assembled LIBs exhibited reduced polarization and enhanced electrochemical properties attributed to facile charge transfer at the interface. The results revealed that Gr│carbon‐BIT@C‐lithium bistrifluoromethane sulfonimide (LiTFSI)/silicon dioxide (SiO 2 )/poly allyl acetoacetate (PAAA)/poly(vinylidene fluoride‐hexafluoropropylene) (P(VDF‐HFP))/polyvinylidene fluoride (PVDF)│LiFePO 4 (LFP) batteries achieved an initial discharge specific capacity of 120.4 mAh g −1 with stable performance over 1200 cycles at 2 C and room temperature (RT), maintaining a Coulombic efficiency of 99.5% after 1200 cycles. The ferroelectric‐modified interface addressed challenges associated with ion transport at the electrode‐electrolyte interface.