A 3D-printed framework with a gradient distributed heterojunction and fast Li+ conductivity interfaces for high-rate lithium metal anodes. Issue 45 (8th November 2022) - Wang, Shuo
Abstract : A 3D framework with a gradient-distributed heterojunction and fast Li + conductivity Li–Al–O interfaces promotes the rate performance in lithium metal anodes. Abstract : A bottleneck limiting the practical application of lithium metal anodes is the uncontrolled growth of lithium dendrites caused by gradient distributed Li + from separators to collectors. Herein, 3D-printed frameworks with a gradient distributed heterojunction and fast Li + conductivity interfaces are developed to regulate the Li + distribution and the direction of dendrite growth. More importantly, the effect of different Li + concentration gradient frameworks on Li + deposition behavior was analyzed in detail. Synchrotron X-ray tomography demonstrates that macropores dominate the framework, which effectively suppresses the volume change caused by lithium deposition. DFT calculations confirm the high lithiophilicity of γ-Al2 O3 and the graphene heterojunction. Synchrotron radiation-based soft X-ray absorption spectroscopy illustrates the fast Li + conductivity Li–Al–O interface resulting from the shortened Al–O bond distance. Benefiting from the higher Li + concentration differences during the dissolution process and Li–Al–O interfaces, the gradient framework can achieve a high rate performance of ∼40 mV overpotential at 10 mA cm −2 and long cycle stability of ∼1500 h at 1 mA cm −2 .