Understanding and Improving Mechanical Stability in Electrodeposited Cu and Bi for Dynamic Windows Based on Reversible Metal Electrodeposition

Abstract

Zn) to dynamic glazings with applications for thermal emissivity (e.g., Ag) or windows (e.g., Cu, Bi, Ag, and Zn). In each of these systems, a layer of metal is electroplated for the system's designed purpose: energy storage for batteries, [1][2][3][4] infrared light modulation for dynamic thermal emissivity, [5] and visible light modulation for dynamic windows. [6][7][8] The mechanical stability of the electrodeposited films is paramount for the devices' durability in practical applications. Mechanical failure can occur in the form of detached dendrites, "dead" metal, pits, and cracked or delaminated films, which usually result in loss of active material leading to device failure. The mechanics of electrodeposited Li has been extensively studied for Li metal batteries. [9,10] Dynamic windows allow for electronic and user control over light and

The Progress and Outlook of Multivalent‐Ion‐Based Electrochromism

“…Reproduced with permission. [ 83 ] Copyright 2023, Wiley VCH. d) Cyclic voltammetry and corresponding transmission vs voltage curves of Bi–Cu electrolyte with bare indium tin oxide (ITO), Pt film ITO, or Pt–nanoparticle (NP)‐decorated ITO working electrodes, and Ag/AgCl reference electrode at a scan rate of 20 mV s −1 .…”

“…RME of Cu 2+ and Bi 3+ have been attempted in aqueous acidic ClO 4 − electrolytes, the residual stress in electrodeposited Cu and Bi films are quantified as presented in Figure 4c. [ 83 ] Despite the excellent electrochromic performance of Cu–RME dynamic windows in acidic ClO 4 − electrolytes, electrodeposited Cu films suffer from limited rest stability due to the tensile stress and stress‐corrosive cracking, leading to fracture and delamination of the electrodeposited Cu film within 24 h soaking in electrolyte. On the contrary, electrodeposited Bi with compressive stress can sustain a longer rest stability for more than 9 weeks.…”

“…[15,82] RME is an fascinating technology that are drawing attention in metal batteries (e.g., Li, Na, and Zn batteries) and dynamic glazings. [83] Aside from the multivalent-ion-intercalation/deintercalation-induced electrochromism, multivalent ECDs based on RME are also promising for thermal management and dynamic windows with color neutrality, fast switching, and durability. [84] As schemed in Figure 4a, generally this type of ECD is also assembled with working electrode and counter electrode (metal frame/metal mesh) sandwiching electrolyte in between.…”

“…It is estimated that smart windows can increase worker productivity by 2% with optimal temperature and lighting control, and render 10-20% energy saving in buildings by reducing heat, ventilation, and air-conditioning energy consumption. [2,83,84] Commercial electrochromic smart windows have been developed by Sage, [105] View, [106] Halio, [107] etc., mostly based on vacuum-deposition technology, hindering the scalability and wide adoption of electrochromic smart windows. Solution-processed multivalent smart windows have been achieved in both ion intercalation and RME-based ECDs.…”

Water-in-Salt Electrolytes for Reversible Zinc Electrodeposition for Dynamic Windows

“…14,15 Reversible metal electrodeposition is a promising method of constructing dynamic windows with adjustable tinting. 16,17 RME windows are typically composed of three main components. [18][19][20] These components are a transparent conducting working electrode such as tin-doped indium oxide (ITO), a counter electrode to charge balance the device, and a gel or liquid electrolyte containing salts of colorless metal ions.…”