High-performance sandwiched hybrid solid electrolytes by coating polymer layers for all-solid-state lithium-ion batteries

Poly(vinylidenefluoride-co-hexafluoropropylene) (P(VDF-HFP))/Li1.3Al0.3Ti1.7(PO4)3 (LATP)/P(VDF-HFP) sandwiched hybrid solid electrolytes were precisely tailored and successfully fabricated to assemble into all-solid-state lithium-ion batteries, which were systematically evaluated on microstructure, morphology, thermal stability and electrochemical performance. The sandwiched hybrid solid electrolytes can achieve intimate contact with cathode and anode electrodes to present an excellent interfacial stability. Furthermore, the sandwiched hybrid solid electrolytes possess flexible surface, wide electrochemical working window of 4.7 V, high ionic conductivity of 0.763 mS·cm−1 and high thermal stability of 460 °C, which may contribute to realizing the practical application in all-solid-state lithium-ion batteries. The assembled cells with the hybrid solid electrolytes can quickly stabilize at a specific discharge capacity of 145.4 mAh·g−1 at 0.1C after only 5 cycles and present admirable rate performance. In addition, morphology characterizations of the sandwiched hybrid solid electrolytes after long-term cycles show a relatively integrated structure coating with a compact LATP layer. The investigations afford a promising strategy that the sandwiched hybrid solid electrolytes can overcome the mechanical limitations of the interface between electrodes and inorganic solid electrolytes to provide favorable properties for all-solid-state lithium-ion batteries.