Retracted: Radical Covalent Organic Frameworks Associated with Liquid Na‐K toward Dendrite‐Free Alkali Metal Anodes

Abstract

Liquid sodium‐potassium (Na‐K) alloy has the characteristics of high abundance, low redox potential, high capacity, and no dendrites, which has become an ideal alternative material for potassium/sodium metal anodes. However, the high surface tension of liquid sodium potassium alloy at room temperature makes it inconvenient in practical use. Here, the Na‐K as reducing agent treats with hydrazone linkages of covalent organic frameworks (COFs) and obtain the carbon‐oxygen radical COFs (COR‐Tf‐DHzDM‐COFs). The preparation method solves the problems that the preparation process of the traditional Na‐K composite anode is complex and has high cost. The structures of the COR‐Tf‐DHzDM‐COFs are characterized by X‐ray diffraction （XRD), fourier transform infrared (FT‐IR), electron paramagnetic resonance (EPR), and solid‐state NMR measurements. It is the first time that carbon‐oxygen radical COFs from bulk COFs are constructed by one‐step method and the operation is flexible, convenient, and high rate of quality, which is suitable for big production and widely used. The cycle stability of the composite Na‐K anode is improved, which provides a new idea for the design of high‐performance liquid metal anode.

Advances in functional organic material-based interfacial engineering on metal anodes for rechargeable secondary batteries

“…16d). 173 The COR-Tf-DHzDM-COFs@Na–K composite anode could not only effectively inhibit dendrite formation, but also exhibit excellent cycle stability of K and Na metal batteries (Fig. 16e and f), which was associated with the synergistic effect of fast electron/mass transport of the cross-linked networks and the self-healing feature of the Na–K alloy.…”

“…Cycling stability of symmetric cells of COR-Tf-DHzDM-COF@Na-K@Cu foam in (e) potassium and (f ) sodium metal anodes. Reproduced with permission 173. Copyright 2022, Wiley-VCH GmbH.…”

Multi‐scale structure engineering of covalent organic framework for electrochemical charge storage

“…Based on this, [TEMPO]100%‐NiP‐COF with 100% TEMPO decoration delivers the highest 167 F g −1 capacitance at 0.1 A g −1 . In addition, Si and co‐workers 115 designed a 2D COFs with carbon–oxygen radicals (i.e., COR‐Tf‐DHzDM‐COFs) to serve as dendrite‐free alkali metal anodes (Figure 7E,F). Carbon–oxygen radicals with high redox reactivity endow COR‐Tf‐DHzDM‐COFs with enhanced charge storage capability, but sacrificing the stability of skeleton.…”

“…(F) Schematic diagram of Tf‐DHzDM‐COFs@Na‐K composites used as anode for dendrite‐free metal battery. Copyright, 2022 Wiley 115 …”

Emerging Solutions to Enable the Efficient Use of Sodium Metal Anodes: Progress and Perspectives

“…In addition, the introduction of desirable metal elements is beneficial for adjusting sodiophilic environments in the Na anode and regulating the transport of Na + , therefore promoting the uniform deposition of Na. [115] For such a purpose, alloying Na as an alternative to Na metal anode has been proposed to enhance the cycling lifespan and performances of SMBs. Several concerns are known to exist for the Na-Li, Na-K, Na-Sn, Na-In, Na-Cs, Na-Rb systems.…”