High‐Index Zinc Facet Exposure Induced by Preferentially Orientated Substrate for Dendrite‐Free Zinc Anode

Abstract

Cu (1 1 1) facet exposure can promote zinc nucleation and uniformize zinc growth. [6] The expensive Cu (1 0 0) single-crystal has also been used to inhibit the generation of zinc dendrites. [7] However, there is a limited prospect for graphene, copper nanowires, copper foam, and copper single-crystal because of their high cost. [8] Therefore, it is essential to develop more efficient and low-cost substrate regulation strategies.Electrolytic copper foil is a widely used commercial current collector with mature fabrication technology and acceptable cost. [9] Selective facet exposure during the electrolysis of copper foils has been proven to be easily achievable in existing copper foil preparations. [10] It may be a promising method to prepare specially oriented copper foils by electrolysis for practical applications. Various facets such as (1 1 1), (2 0 0), (2 2 0), and (3 1 1) may be exposed during the copper electrolysis process. [11] If the zinc deposition activity of these facets is identified, zinc deposition can be efficiently regulated by selectively exposing the most active facet. In addition to the effect of substrate facet exposure on zinc deposition, the exposed zinc facets during the deposition process can also influence the subsequent zinc deposition because of the different activities of the different zinc facets. [12] Crystal growth theory suggests that the fast-growing crystalline facets tend to disappear gradually, while slow-growing facets are preferentially exposed. [13] This critical conclusion is usually overlooked by some researchers who determine the preferential growth or exposure of crystal facets only by the intensity of the X-ray diffraction (XRD) peaks. This approach is usually inadequate because the relative peak intensities of bulk samples are related to the grain alignment orientation. [14] Electron backscatter diffraction (EBSD) can be used to precisely analyze the correlation between crystal facet growth and exposure to understand the zinc growth mechanism during electrodeposition. Based on the above considerations, fabrication of copper substrates with high active facet exposure by electrolysis and in-depth study of zinc growth mechanism on substrates are important to enhance its reversibility for zinc plating and stripping.In this work, we reveal the highest zinc deposition activity of Cu (2 2 0) facet in comparison with other low-index crystal facets by optical microscopy and EBSD techniques. An industrial electrolysis method is proposed to construct Cu (2 2 0) substrate with highly preferential orientation, denoted as PCu. This uniformly oriented substrate with zincophilicity can playThe most commonly used zinc foil anode for aqueous zinc-ion batteries suffers from poor cycle stability and low zinc utilization. Zinc-plated anodes on the host materials with high zincophilicity and stability are receiving increasing attention to alleviate these above issues. Here, the high zinc deposition activity of Cu (2 2 0) is confirmed through experimental observations and theoretical cal...

Robust and Wide Temperature‐Range Zinc Metal Batteries with Unique Electrolyte and Substrate Design

“…Optical photographs of the substrates after zinc deposition also illustrate that Al@C foil induces a uniform zinc deposition (Figure S27). The results of in situ XRD tests (Figure 5i and Figure S28) and crystal structure simulations (Figure 5j) illustrate that the zinc plating/stripping on Al@C foil is highly active with fine grains, Zn(0 0 1) facet stacking and selective exposure of Zn(1 0 1) facets [10] . The best electrolyte wettability of Al@C foil compared to copper foil and Al foil (Figure S29) also indicates that carbon particles can optimize zinc deposition by homogenizing the ion distribution.…”

“…It is believed that this unique γ‐valerolactone‐based electrolyte can solve the problems of dendrites, corrosion, and HER in zinc metal anodes according to the above results and analysis. The zinc foil anode commonly used in laboratory studies is difficult to maintain stability after deep charge–discharge cycles because it suffers from perforation and shedding [10, 12a] . However, a high depth of discharge is the primary requirement for high‐energy‐density batteries (Figure S19).…”

“…Organic electrolytes with intrinsic chemical stability can improve the Coulombic efficiency of zinc anodes, but cannot completely solve the problems of dendrite growth, slow kinetics, and extreme temperature tolerance [9] . Zinc foil is not the optimal anode choice for practical applications since it tends to perforate and detach at high depths of discharge and struggles to maintain a stable conductor interface [10] . The perforation problem of the electrodes can be inherently solved by using inert substrates.…”

Research progress on modified Zn substrates in stabilizing zinc anodes

“…Xie et al confirmed the high zinc deposition activity of Cu (220) by experimental observation and theoretical calculation and prepared Cu (220) substrates with high selective orientation using an industrial electrolytic strategy. 116 The as-prepared Cu (220) substrate is able to induce Zn (001) growth and expose a high refractive index zinc surface with the lowest surface energy due to its special grain size, high deposition activity and uniform grain orientation, which continuously regulates the growth of dense zinc, resulting in a high reversibility of galvanization/dezincification of this Cu (220) substrate. When incorporated into the Zn//MnO 2 battery, the zinc-plated copper (220) can maintain a capacity retention of 93.9% after 640 cycles, with a zinc utilization rate of approximately 20%.…”

Post Nitrogen Electrocatalysis Era From Li–N2Batteries to Zn–N2Batteries

“…[ 76 ] Oriented Cu (220) substrates are proved to be capable of consistently modulating the dense zinc deposition by inducing the growth of Zn (001) due to its exceptional grain size, high zinc deposition activity, and homogeneous crystal orientation. [ 77 ] Actually, it is more inclined to combine both surface modification and structural design to modify Zn anode metals. Recently, a kind of single atomic ZIF coating layers was also studied.…”