Dendrite‐Free Zinc Deposition Induced by Tin‐Modified Multifunctional 3D Host for Stable Zinc‐Based Flow Battery

Abstract

choices for such systems due to their attractive features of high safety, low cost, and long cycle life. [3] In a typical ZFB, metallic zinc (Zn) plating/stripping, processing low electrochemical potential (−0.762 vs the standard hydrogen electrode (SHE)), rapid reaction kinetics, and environmental friendliness, is well suitable for anodic electrochemical reaction. [4] However, the realization of high cycling stability and long life of a ZFB has to face the intricate challenges from Zn anode: dendrite formation, as a result from inhomogeneous Zn plating during the process of charging, leads to internal short circuit failure and increase in surface area of Zn anode, which accelerates corrosion and decreases the utilization of Zn deposited onto anode; during the process of discharging. The dendrite formation will aggravate the uneven Zn stripping and the formation of dead Zn, and then decrease the coulombic efficiency (CE). [5] Therefore, uniform and dense Zn deposition is of great necessity for a long life ZFB. However, it is extremely challenging to obtain an even and dense deposition of Zinc for rechargeable ZFBs. [6] To overcome this problem, the addition of inorganic, organic, and polymeric additives is proposed to control the dendritic growth. [7] Unfortunately, these usually increase polarization, or are expensive and even environmentally hazardous. On the other hand, these proposals mostly address the problem from the perspective of electrolyte. It is full of strategic importance to explore other methods (for example, anode modification), which may work better in combination with additives. Moreover, many methods related to aqueous Zn-based battery system have been provided, e.g., 3D architecture Zn, backsideplating Zn, water-in-salt electrolyte, construction of artificial solid-electrolyte interface, ionic liquid containing nickel triflate and metal-organic framework host. [8] Much progress has been made in the aspect of inhibition of dendrite growth. However, considering their real medium and the state-of-art configuration, these methods cannot be transplanted to ZFBs. Therefore, there is an urgent need to propose effective methods to inhibit dendrite growth especially focusing on ZFBs.Herein, we propose and fabricate a multifunctional binderfree tin (Sn) modified 3D carbon felt anodic host (SH) for zinc deposition via a facile and scalable strategy by magnetron sputtering. The results demonstrated that: according to the experimental and computational simulation results, the Zinc (Zn) plating/stripping is a promising anodic electrochemical reaction for aqueous batteries because of its high safety, low cost, two electron transfer, and rapid reaction kinetics. However, the notorious dendrite growth of Zn has become one of the biggest obstacles hindering its further commercialization. A multifunctional binder-free tin (Sn)-modified 3D carbon felt anodic host (SH) is constructed for aqueous zinc-based flow batteries (ZFB) via a facile and scalable strategy. Compared with the pristine carbon felt host (...

An Interface‐Bridged Organic–Inorganic Layer that Suppresses Dendrite Formation and Side Reactions for Ultra‐Long‐Life Aqueous Zinc Metal Anodes

“…[21] To address the above issues,t he currently reported solutions can be divided into two aspects:s uppressing dendrite formation and minimizing side reactions.D endrite suppression can be achieved by introducing coating layers on Zn anode surface,which effectively modified the current and electrolyte flux on anode surface,s uch as CaCO 3 and SiO 2 layer, [22] porous active carbon layer and reduced graphene oxide (rGO) layer, [23,24] and so on. Furthermore,m any strategies have also been reported for relieving the side reactions beside suppressing dendrites,i ncluding coating az incophilic protective layer, [25] replacing ZnSO 4 with Zn-(CF 3 SO 3 ) 2 , [26] using electrolyte additives, [27][28][29] adoption of ah ighly concentrated zincic salt as electrolyte, [30] using modified conductive host, [31][32][33][34] employing single ion conduc-tive electrolyte, [35,36] alloying with Al, [37] adopting gel electrolyte or all solid electrolyte, [38][39][40] coating inorganic layer, [41][42][43][44] or organic (polyamide) layer. [45] Indeed, the side reactions and dendrite are very important issues for long life AZBs.…”

Challenges and Strategies for Constructing Highly Reversible Zinc Anodes in Aqueous Zinc‐Ion Batteries: Recent Progress and Future Perspectives

“…Besides the 3D porous metal skeleton, 3D carbon nanomaterials such as carbon cloth (CC), [ 49 ] 3D carbon nanotube (CNT) network, [ 50 ] 3D graphene foam, [ 50b ] and 3D carbon felt [ 51 ] have also been testified to be ideal choices for 3D zinc preparation. However, Zn 2+ ions cannot be easily adsorbed on the surface of carbon because of the binding energy between zinc atom and carbon is lower than that between zinc atom and zinc surface, which indicate that zinc prefers to be plated on the initially nucleated zinc sites rather than on the carbon surface.…”

“…Furthermore, the Sn modified 3D carbon felt anodic host (SH) can provide more robust zinc nucleation sites, higher overpotential for HER, and lower zinc deposition overpotential, which synergistically induced zinc to deposit uniformly and densely. [ 51 ]…”

Rechargeable Aqueous Zinc‐Ion Batteries with Mild Electrolytes: A Comprehensive Review

“…[176] Introducing heterogeneous nuclei (such as Sn nano-particles) onto current collectors is also helpful for the achievement of high performance Zn anodes. [193] In situ electro-healing strategy for in-service Zn anodes: The formation of Zn dendrites are severely dependent on the charge/discharge conditions of the ZIBs. [170] That is, the growth of Zn dendrites, as well as the degradation of ZIBs' performance, is much faster at large current densities or deep DOD.…”