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

Abstract

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 Cu 2 O/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 Cu 2 O of the substrate to generate Li 2 O, 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−Cu 2 O (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.

Copper Current Collector: The Cornerstones of Practical Lithium Metal and Anode–Free Batteries

“…Unlike in–situ conversion, direct ASEI construction mostly uses chemical–inactive organics as the covering material. In the recent works, organic ASEI such as MOFs, [130] PVDF, [131] PDMS, [132] organsilane, [133] BTA, [134] PES, [135] LDS, [136] PAN, [137] sodium alginate, [138] CMC−Li, [139] and so on have been reported. These decorations can well endure the volume change and suppress the dendrite formation, and their chemical inertness can protect the inner lithium from being attacked by electrolyte.…”

Nitrogen Ion Implantation-Modified Cu Substrate for Stable Lithium Metal Anode

“…Various strategies have been made to modify the Cu substrate, such as high-temperature calcination, spin coating, chemical vapor deposition, and electrospinning . However, most of these methods require complex design and material synthesis procedures, which will increase the complexity of the LMA fabrication process, while, in some cases, the large addition of inactive substances will reduce the energy density of the LMBs.…”