Controlling electrochemical growth of metallic zinc electrodes: Toward affordable rechargeable energy storage systems

Abstract

Scalable approaches for precisely manipulating the growth of crystals are of broad-based science and technological interest. New research interests have reemerged in a subgroup of these phenomena—electrochemical growth of metals in battery anodes. In this Review, the geometry of the building blocks and their mode of assembly are defined as key descriptors to categorize deposition morphologies. To control Zn electrodeposit morphology, we consider fundamental electrokinetic principles and the associated critical issues. It is found that the solid-electrolyte interphase (SEI) formed on Zn has a similarly strong influence as for alkali metals at low current regimes, characterized by a moss-like morphology. Another key conclusion is that the unique crystal structure of Zn, featuring high anisotropy facets resulting from the hexagonal close-packed lattice with a c/a ratio of 1.85, imposes predominant influences on its growth. In our view, precisely regulating the SEI and the crystallographic features of the Zn offers exciting opportunities that will drive transformative progress.

Mechanistic Insights of Mg2+‐Electrolyte Additive for High‐Energy and Long‐Life Zinc‐Ion Hybrid Capacitors

“…According to the XRD investigation after different charge‐discharge cycles, the Zn(002) plane becomes the preferred and dominating deposition plane as a result of homogeneous nucleation in the ZnMg‐0.1 electrolyte (Figure S17, Supporting Information). [ 40,41 ] Unlike the corrosion pits on the Zn surface formed by side reaction in 2 m ZnSO 4 , the SEM image of Zn in ZnMg‐0.1 shows a smooth garment, which is similar to the untreated Zn (Figure S18, Supporting Information). These two different behaviors illustrate the decisive role of the Mg 2+ additive in guiding the Zn deposition behavior, leading to a uniform plating layer without evident Zn dendrites, as discussed in detail below.…”

Stabilizing Zinc Electrodeposition in a Battery Anode by Controlling Crystal Growth

“…There is a variety of consideration for selecting Zn for the study; the most important include: i) Zn anodes in neutral aqueous electrolytes do not form complicated solid–electrolyte interphase layers. [ 6,12,21,22 ] The presence of such layers would complicate adsorption processes at the electrode and we believe reduce the fidelity with which polymer, salt, and other known crystal growth‐regulation agents are able to regulate crystal growth process at a Zn anode. ii) Our prior success regulating Zn crystallization in the Zn‐graphene system [ 6 ] confirms the importance of consideration (i).…”

A highly stable lithium metal anode enabled by Ag nanoparticle–embedded nitrogen-doped carbon macroporous fibers

“…Owing to the ultrahigh theoretical specific capacity (3861 mAh g −1 ) and low redox potential (−3.04 V versus standard hydrogen electrode), metallic lithium has been regarded as one of the most promising anode materials for high-energy density rechargeable batteries (1)(2)(3)(4)(5)(6). However, the uncontrollable growth of Li dendrites and collapse of the solid electrolyte interphase (SEI) layer lead to low Coulombic efficiency (CE) and deteriorated cycling performance, which largely restrict the practical application of the Li metal anode (LMA) (7)(8)(9)(10)(11)(12)(13). Considerable efforts have been made to regulate the Li plating/ stripping behaviors for stable Li metal batteries, including developing functional electrolytes (14)(15)(16)(17)(18), constructing well-designed three-dimensional (3D) host structures (19)(20)(21)(22)(23)(24), and using artificial protection layers (25)(26)(27)(28)(29)(30).…”