Multiple uniform lithium-ion transport channels in Li6.4La3Zr1.4Ta0.6O12/Ce(OH)3 modified polypropylene composite separator for high-performance lithium metal batteries.

With the introduction of Ce(OH) 3 , the composite electrolyte layer coating on the PP separator provides a variety of Li-ion transport channels. Coupling with LiFePO 4 (LFP) cathode and Li metal, the cells exhibit long-term cycling stability and highly capacity retention of 91.6 % after 400 cycles. [Display omitted] • The Ce(OH) 3 composite with LLZTO provides multiple effective transport channels for the uniform distribution of Li ions. • Three dimensional of Li+ transport network in the composite electrolyte layer on the PP separator. • LLZTCO@PP exhibits elevated ionic conductivity (>10– 3 S cm– 1) at room temperature, a broad electrochemical window (>4.8 V) and high lithium ion transference number of 0.73. • The cells using LLZTCO@PP exhibit a dendrite-free morphology during repeated discharge–charge, remarkable cycling stability and capacity retention. Lithium (Li) metal anodes (LMAs) are regarded as leading technology for advanced-generation batteries due to their high theoretical capacity and favorable redox potential. However, the practical integration of LMAs into high-energy rechargeable batteries is hindered by the challenge of Li dendrite growth. In this work, nanoparticles of Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) loaded with Ce(OH) 3 (LLZTCO) were designed and synthesized by a hydrothermal method. A functional composite separator was crafted by coating one side of a polypropylene (PP) separator with a composite electrolyte comprised of polyvinylidene fluoride (PVDF) and LLZTCO. The synergistic interactions between PVDF and LLZTCO provide numerous rapid lithium-ion (Li+) channels, facilitating the efficient redistribution of disparate Li+ flux originating from the insulated PP separator. The composite separator demonstrated an ionic conductivity (σ) of 3.68 × 10–3 S cm−1, substantial Li+ transference number (t+) of 0.73, and a high electrochemical window of 4.8 V at 25℃. Furthermore, the Li/LLZTCO@PP/Li symmetric cells demonstrated stable cycling for over 2000 h without significant dendrite formation. The Li/LiFePO 4 (LFP) cells assembled with LLZTCO@PP separators exhibited a capacity retention of 91.6 % after 400 cycles at 1C. This study offers a practical approach to fabricating composite separators with enhanced safety and superior electrochemical performance. [ABSTRACT FROM AUTHOR]