A Review on Covalent Organic Frameworks as Artificial Interface Layers for Li and Zn Metal Anodes in Rechargeable Batteries

Abstract

Li and Zn metals are considered promising negative electrode materials for the next generation of rechargeable metal batteries because of their non‐toxicity and high theoretical capacity. However, the uneven deposition of metal ions (Li+, Zn2+) and the uncontrolled growth of dendrites result in poor electrochemical stability, unsatisfactory cycle life, and rapid capacity decay of batteries assembled with Li and Zn electrodes. Owing to the unique internal directional channels and abundant redox active sites of covalent organic frameworks (COFs), they can be used to promote uniform deposition of metal ions during stripping/electroplating through interface modification strategies, thereby inhibiting dendrite growth. COFs provide a new perspective in addressing the challenges faced by the anodes of Li metal batteries and Zn ion batteries. This article discusses the stability and types of COFs, and summarizes some novel COF synthesis methods. Additionally, it reviews the latest progress and optimization methods of using COFs for metal anodes to improve battery performance. Finally, the main challenges faced in these areas are discussed. This review will inspire future research on metal anodes in rechargeable batteries.

Organic solid–electrolyte interface layers for Zn metal anodes

“…Compared to the methods above, the design of artificial SEIs provides a direct physical barrier between the anode and electrolyte, which can effectively stabilize the Zn anode without affecting the ion conductivity of the electrolytes. 67 Numerous artificial SEI layers, including fluoride materials, 68,69 oxide materials, 70,71 metals, 72,73 alloys, 74 MXene materials, 75,76 carbon materials, 77,78 and organic materials 79–81 have been developed. Well-designed SEI layers can induce uniform Zn plating by regulating the Zn 2+ flux, regulating the surface electric field, and facilitating the de-solvation process.…”

Nanoporous Triazine-Framework-Assembled Electrolyte Interphase Layer as a Lithiophilic Gridding for Uniform Lithium Deposition and Dendrite Inhibition

“…Various strategies have been proposed to solve these challenges of LMAs, − including establishing external barriers, such as a nanosized electrode matrix, a shape-congruous solid electrolyte membrane, and a soft three-dimensional (3D) current collector, to regulate Li + and free solvent molecules’ transfer behavior adjacency to the anode interface. − These strategies highlight the impressive effects of the interface protective layer to revive LMA. Recently, micro/nanostructured hosts endowed with fully exposed lithiophilic sites, abundant pores, and robust spatial dimension skeletons have been widely developed as an artificial interface layer to regulate Li-metal deposition/dissolution behaviors, which effectively supports the rapid Li + diffusion and inhibits lithium dendrite growth. ,− The emerging class of highly crystalline porous organic polymer (POP) materials composed of lightweight elements (C, N, H, O, etc.)…”