Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Schematic diagram of CSSEs preparation and their cycling performance at 1C rate.


ABSTRACT
Owing to its high lithium-ion conductivity, the cubic garnet-phase material Li7La3Zr2O12 (LLZO) is a widely adopted key component in the fabrication of composite solid-state electrolytes (CSSEs). Nevertheless, the advancement of all-solid-state lithium batteries (ASSLBs) is still hindered by two major challenges: the high intrinsic crystallinity of poly(ethylene oxide) (PEO) and poor interfacial stability. Herein, cubic garnet Li6.3La2.7Ba0.3ZrNbO12 (LLBZNO) featuring Ba and Nb co-doping was first prepared by a conventional solid-state method. Following this, the material was dispersed within a PEO matrix to construct composite solid-state electrolytes. Adding LLBZNO served to decrease PEO's crystallinity while enhancing its mechanical flexibility and bolstering its interfacial compatibility with lithium metal. The optimized membrane demonstrated superior properties, including a high Li+ transference number of 0.75 (at 60°C) and an extended electrochemical stability window of up to 5.1 V (vs. Li/Li+) under the present testing conditions. It also showed an excellent ability to suppress dendrites, facilitating stable cycling at 0.1 mA cm−2 for 1500 h without short-circuiting. Furthermore, the LFP/LLBZNO–PEO/Li battery delivered a high discharge capacity of 101.6 mA h g−1 after 300 cycles at 1°C with nearly 99% coulombic efficiency. These findings highlight that LLBZNO-PEO composite solid electrolytes possess superior ionic transport, electrochemical stability, and mechanical robustness, providing a viable pathway toward the advancement of next-generation high-performance ASSLBs.