Multiple uniform lithium-ion transport channels in Li_6.4La₃Zr_1.4Ta_0.6O₁₂/Ce(OH)₃ modified polypropylene composite...

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_6.4La₃Zr_1.4Ta_0.6O₁₂ (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/LiFePO₄ (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.