Horizontally arranged zinc platelet electrodeposits modulated by fluorinated covalent organic framework film for high-rate and durable aqueous zinc ion batteries

Abstract

Rechargeable aqueous zinc-ion batteries (RZIBs) provide a promising complementarity to the existing lithium-ion batteries due to their low cost, non-toxicity and intrinsic safety. However, Zn anodes suffer from zinc dendrite growth and electrolyte corrosion, resulting in poor reversibility. Here, we develop an ultrathin, fluorinated two-dimensional porous covalent organic framework (FCOF) film as a protective layer on the Zn surface. The strong interaction between fluorine (F) in FCOF and Zn reduces the surface energy of the Zn (002) crystal plane, enabling the preferred growth of (002) planes during the electrodeposition process. As a result, Zn deposits show horizontally arranged platelet morphology with (002) orientations preferred. Furthermore, F-containing nanochannels facilitate ion transport and prevent electrolyte penetration for improving corrosion resistance. The FCOF@Zn symmetric cells achieve stability for over 750 h at an ultrahigh current density of 40 mA cm−2. The high-areal-capacity full cells demonstrate hundreds of cycles under high Zn utilization conditions.

Construction of Mixed Ionic‐Electronic Conducting Scaffolds in Zn Powder: A Scalable Route to Dendrite‐Free and Flexible Zn Anodes

“…In particular, Zn anodes experience uncontrollable Zn dendrite growth during the repeated uneven Zn stripping/plating process (Figure 1a), which easily induces short-circuits, representing a safety hazard, and causes irreversible capacity loss, poor cycling efficiency, and an inferior rate performance for Zn-based batteries. [9,10] To address this limitation, considerable effort has been devoted to mitigate Zn dendrite growth by developing various strategies, such as adjustment of electrolyte composition, [11][12][13][14][15] construction of an artificial solid-electrolyte interphase, [16][17][18][19][20] modification of the separator, [21][22][23] and the engineering of structured Zn anodes. [24,25] One promising approach is to build a 3D structural scaffold for confining Zn, which would effectively contain the uniform Zn stripping/plating behavior inside the anode framework, thereby enhancing the cycling stability of Zn metal anodes.…”

A MOF‐Derivative Decorated Hierarchical Porous Host Enabling Ultrahigh Rates and Superior Long‐Term Cycling of Dendrite‐Free Zn Metal Anodes

“…[ 6–8 ] Unfortunately, the uncontrolled formation of dendrites, undesired side reactions (e.g., corrosion, hydrogen evolution, and by‐product formation), and huge volume variation during repeated Zn deposition–dissolution processes of the host‐less metallic Zn anode not only limit the efficiency of plating and stripping, but also result in a remarkably short lifespan, or even internal short‐circuiting. [ 9–11 ]…”

“…[6][7][8] Unfortunately, the uncontrolled formation of dendrites, undesired side reactions (e.g., corrosion, hydrogen evolution, and by-product formation), and huge volume variation during repeated Zn deposition-dissolution processes of the host-less metallic Zn anode not only limit the efficiency of plating and stripping, but also result in a remarkably short lifespan, or even internal short-circuiting. [9][10][11] In order to address the issues mentioned above, several strategies have been proposed to regulate the Zn plating/stripping behaviors for stable Zn metal batteries, including surface modification, [12][13][14] electrolyte optimization, [15][16][17] and electrode structural design. [18][19][20] For instance, an ultrathin MXene layer and glucose have been used as an artificial layer and a multifunctional electrolyte additive to stabilize Zn metal anodes, Aqueous Zn metal batteries have attracted much attention due to their high intrinsic capacity, high safety, and low cost.…”

Vertical Crystal Plane Matching between AgZn3 (002) and Zn (002) Achieving a Dendrite‐Free Zinc Anode

“…[2] However, during Zn stripping/plating, dendrite growth can cause sudden battery death. [3] Most previous efforts have mainly focused on protective covers, [4] metal alloy anode, [5] organic framework film, [6] 3D surface structure, electrolyte regulation, [7] particles and Zn (002) flakes. We achieved an orderly, dense, and dendrite-free Zn anode (Figure 1) through AgZn 3 coating from plasma sputtering technology.…”

“…[ 2 ] However, during Zn stripping/plating, dendrite growth can cause sudden battery death. [ 3 ] Most previous efforts have mainly focused on protective covers, [ 4 ] metal alloy anode, [ 5 ] organic framework film, [ 6 ] 3D surface structure, electrolyte regulation, [ 7 ] and colloid electrolyte, [ 8 ] which, to some extent, can alleviate the corresponding problem to realize improved stripping/plating cycles. [ 9 ] However, achieving dense metallic deposition for long cycle life and high rate performance of Zn metal batteries remains a great challenge.…”