Lithiophilic Interface Layer Induced Uniform Deposition for Dendrite-free Lithium Metal Anodes in a 3D Polyethersulfone Frame

Lithium metal anodes possess ultrahigh theoretical specific capacity for next-generation lithium metal batteries, but the infinite volume expansion and the growth of lithium dendrites remain a huge obstacle to their commercialization. Therefore, here, we construct a CuO-loaded 3D polyethersulfone (PES) nanofiber frame onto a lithiophilic Cu2O/Cu substrate to promote the lithium storage performance of the composite anode, and the 3D frame can effectively alleviate the volume expansion of lithium (Li) metal anodes. Meanwhile, lithium reacts with CuO in the composite nanofiber and Cu2O of the substrate to generate Li2O, which can strengthen the solid electrolyte interface (SEI) layer and achieve the uniform deposition of lithium. In addition, the combination of the heat treatment method and electrospinning technology solves the problem of poor adhesion between the fiber film and the substrate. As a result, the PES/CuO-Cu2O (PCC) composite current collector still maintains a smooth and flat lithium-depositing layer at 5 mA cm-2. The PCC-assembled Li||Cu halfcell can operate stably for 320 cycles at 0.5 mA cm-2, which is about 4 times that of bare Cu. Furthermore, symmetrical batteries with PCC@Li can maintain excellent cycle stability for 1770 h. Accordingly, this work provides a low-cost and highly effective strategy for stabilizing the lithium metal anode.

Automated summary

To address the issues of volume expansion and lithium dendrite growth in lithium metal anodes, researchers have developed a CuO-loaded composite anode with a 3D polyethersulfone nanofiber frame, which effectively mitigates volume expansion. The reaction between lithium and CuO in the composite nanofiber, as well as Cu2O in the substrate, forms Li2O, strengthening the solid electrolyte interface (SEI) layer and ensuring uniform lithium deposition. The combination of heat treatment and electrospinning resolves the adhesion problem between the fiber film and the substrate. This study provides a low-cost and highly effective strategy for stabilizing lithium metal anodes.