Electrolyte based on laser-generated nano-garnet in poly(ethylene oxide) for solid-state lithium metal batteries

The embedding and even dispersing of Nano-LLZTO with sizes down to averagely 8.3 nm in PEO-based electrolyte could provide sufficient interfacial contact sites with PEO, thus effectively reducing the PEO crystallinity and allowing smooth ion conduction pathways. • Nano-LLZTO with sizes down to 8.3 nm is in-situ generated via liquid-phase laser. • Nano-LLZTO CSE shows low thickness but enhanced tensile strength tolerance. • Nano-LLZTO CSE exhibits highest Li + conductivity by adding only 2.0 wt% fillers. • Dendrite-suppression capability and interfacial stability are realized. Incorporating ceramic superionic fillers in Li + conductive polymer matrix is an efficient strategy for developing solid-state electrolytes, while challenges remain on embedding ceramic fillers with well-defined size and well-dispersion that could maximize the interfacial interactions and decrease the crystallization of polymer for improved conductivity. Herein we report an intriguing strategy of liquid-phase laser manufacturing to in-situ generate nano Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (Nano-LLZTO) with the average size of 8.3 nm in the presence of PEG. Even dispersion of Nano-LLZTO in poly(ethylene oxide) (PEO) matrix is realized benefiting from the interfacial comparability between PEO and PEG. Such embedding leads to maximally an order of magnitude enhancement of Li + conductivity by incorporating Nano-LLZTO with the content of 2.0 wt%, compared to that of PEO-based electrolyte. Meanwhile, enhanced dendrite-suppression capability and interfacial stability are achieved with a stable and low overpotential of ∼ 108 mV and a long lifespan up to 400 h in symmetric cells, and enhanced tensile strength close to 3.0 MPa and the maximum strain of 2200% are simultaneously achieved. Solid-state batteries comprising of PEO-based electrolyte embedded with Nano-LLZTO demonstrates stable cycling performances over 850 cycles. Thus, the proposed facile design of embedding nano garnet is anticipated to provide an efficient alternative to address the weak Li + conductivity of polymer matrix for high-performance solid-state electrolytes.