Rationally optimized carbon fiber cloth as lithiophilic host for highly stable Li metal anodes

Abstract

Abstract The practical application of lithium metal anode has been greatly hampered by irregular growth of lithium (Li) dendrites and the volume expansion during the cycle. Constructing a three-dimensional lithiophilic porous framework is regarded as an effective solution. Here, utilizing a CuO nanocluster arrays decorated carbon fiber cloth (CuO-NC@CFC) to prestore Li via molten infusion has been testified to effectively resolve these bottlenecks. Impressively, after a violent melt-infusion process, the constructed nanostructures can be maintained and transformed into Cu/Li2O nanocluster arrays, together with highly conductive carbon fiber cloth, provide fast charge transport during Li stripping/plating process. As demonstrated by finite element simulations and experimental evidences, the formed Cu/Li2O nanocluster arrays not only redistribute Li+ flux and reduce local current density but also serve as Li nucleation sites. Consequently, the as-acquired Li/Cu-NC@CFC electrodes could significantly buffer volume fluctuation and regulate Li deposition behavior, exhibiting an ultrastable and ultralong lifespan (400 h at 5 mA cm-2 with 1 mAh cm-2 Li and 800 h at 5 mA cm-2 with 5 mAh cm-2 Li in symmetric cells). When coupled with LiFePO4, the Li/Cu-NC@CFC electrode could deliver a high capacity of 110.3 mAh g-1 after 500 cycles at 2 C.