Polymer solid-state electrolytes (PSSEs) are promising for solving the safety problem of Lithium (Li) metal batteries (LMBs). However, PSSEs with low modulus in nature are prone to be penetrated by lithium dendrites, resulting in short circuit of LMBs. Here, we design and prepare piezoelectric BaTiO₃ doped polyacrylonitrile (PAN@BTO) quasi-solid-state electrolytes (PQSSEs) by electrostatic spinning method to suppress dendritic growth. The piezoelectric polymer electrolytes are squeezed by nucleation and growth processes of Li dendrites, which can generate a piezoelectric electric field to regulate the deposition of Li⁺ ions and eliminate lithium bud. Consequently, piezoelectric PAN@BTO PQSSEs enables highly stable Li plating/stripping cycling for over 2000 h at 0.15 mA/cm² at room temperature (RT, 25 ℃). Also, LiFePO₄|PAN@BTO|Li full cells demonstrate excellent cycle performance (136.9 mA·h/g and 78% retention after 600 cycles at 0.5 C) at RT. Moreover, LiFePO₄|PAN@BTO|Li battery show extremely high safety and can still work normally under high-speed impact (2 Hz, ~30 kPa). We construct an in-situ cell monitoring system and disclose that the mechanism of suppressed lithium dendrite is originated from the generation of opposite piezoelectric potential and the feedback speed of intermittent piezoelectric potential signals is extremely fast.

Silicon-based anodes with high theoretical capacity have intriguing potential applications for high energy density lithium-ion batteries (LIBs), while suffer from immense volumetric change and brittle solid-state electrolyte interface that causes collapse of electrodes. Here, a stress-dissipated conductive polymer binder (polyaniline with citric acid, PC) is developed to enhance the mechanical electrochemical performance between Si nanoparticles (SiNPs) and binders. Benefiting from the stable triangle network node of citric acid and a considerable distributed of hydroxyl groups, the PC binder can effectively dissipate the stress from SiNPs, thus providing an excellent cyclic stability of Si anodes. Both experimental results and theoretical calculation demonstrate the enhanced adhesion between binders and SiNPs could bond the particles tightly to form a robust electrode. The as-fabricated Si anode exhibits outstanding structural stability upon long-term cycles that exhibit a highly reversible capability of 1021 mA·h·g⁻¹ over 500 cycles at a current density of 0.5 C (1 C = 4200 mA·g⁻¹). Evidently, this stress-dissipated binder design will provide a promising route to achieve long-life Si-based LIBs.