Unveiling the Multistep Electrochemical Desorption Mechanism of Cubic NiO Films for Transmissive-to-Black Electrochromic Energy Storage Devices

Abstract

Electrochromic smart windows offer dynamic control of sunshine and solar heat in modern architecture. Yet, how to obtain aesthetically pleasing color tuning states such as gray and black is a great challenge, and the corresponding desorption mechanism in electrochromism is still not well understood. Here, we report one transmissive-to-black NiO electrochromic film assembled by a facile and low-cost electrostatic spray technology, which achieves ultralarge optical modulation, high coloration efficiency, and remarkable energy storage capacity. By in-depth experimental analyses and the first-principle calculations, multistep electrochemical desorption mechanisms of OH– and electrochromic switching kinetics of the NiO film were unveiled. Additionally, the assembled NiO film-based smart energy storage indicator can visually display its energy storage level in real time. Our obtained NiO films and subsequent devices can serve as potential candidates in a broad range of innovative electrochromic applications including multifunctional smart windows, energy-efficient displays, energy-storage indicators, electronic labels, etc.

Advanced inorganic nanomaterials for high-performance electrochromic applications

“…6a and b). 67 The fabricated NiO NCs films exhibited high transparency and black colors and realized a large optical modulation of 83.2% at 550 nm, high coloration efficiency (75.5 cm 2 C −1 ), and superior energy storage capacity (Fig. 6c and d).…”

Enhanced linear and symmetric synaptic weight update characteristics in a Pt/p-LiCoOx/p-NiO/Pt memristor through interface energy barrier modulation by Li ion redistribution

“…45,46 NiO is also a p-type oxide with a band gap energy of about 3.6-4.0 eV. 47,48 It has been researched for various applications, such as gas sensors, 49 perovskite light emitting diodes, 50 electrochromic displays 51 and RRAM devices. 52 Its p-type characteristics come from the presence of Ni vacancies and the resulting Ni 3+ ions.…”

A layer-stacked NiO nanowire/nanosheet homostructure for electrochromic smart windows with ultra-large optical modulation

“…In recent years, great efforts have been put into designing a variety of micro-/nano-structures with various dimensionalities, including nanoparticle-, nanosheet-, and dandelion flower-type NiO films. [11][12][13][14][15] However, the singleness of the reported NiO nanostructures show that their bleaching and coloration states in electrochromism cannot be synchronously optimized, which results in difficult breakthroughs in satisfactory optical modulation. Additionally, the excessive stress generated in the electrochromic process also causes cycling instability for a single NiO structure.…”