Electrochromic Supercapacitors Research Articles

Ammonia controlled synthesis of NiO nanosheet arrays for high-performance electrochromic-supercapacitors

To optimize the synthesis process and improve the electrochromic and energy storage performance of NiO, in this paper, an ammonia hydrothermal method is used to prepare NiO nanosheet array electrodes with dual-functions of electrochromic and energy storage. When the concentration of ammonia reaches pH = 11.5, the prepared electrode exhibits optimal optical modulation capability (79.2 % at 620 nm). Additionally, this electrode also provides a large area specific capacitance (69.5 mF/cm² at 0.2 mA/cm²), good rate capability (maintaining 46.7 mF/cm² at 1.0 mA/cm²), and excellent capacitive stability (retaining 96 % of the initial capacitance after 5000 cycles). These excellent performances are mainly attributed to the hierarchical assembled nanosheets structure, which has a large active surface area and short ion transport paths. Furthermore, the uniform and interlinked self-assembled structure, as well as the preset seed layer significantly enhance the film's structural stability and the adhesion to the substrate. Notably, we also construct electrochromic-supercapacitors (ECSCs). During the charging process, two series-connected ECSCs turn dark brown and light up an LED lamp, while during the discharging process, the ECSCs gradually becomes colorless, and the LED lamp goes out. This study provides directions for the preparation of novel dual-functional visual energy storage materials and boosts the development of dual-functional electrochromic-energy storage devices.

Ti3C2Tx‐MXene‐Based Color‐Indicative All‐Organic Electrochromic Supercapacitors

An all‐organic multifunctional solid‐state electrochromic supercapacitor has been designed by utilizing 2D‐MXene and a combination of viologen and polythiophene. The 2D MXene is synthesized using selective etching method and properly characterized; afterward, it is doped in ethyl viologen (EV) and a solid‐state electrochromic supercapacitor device is prepared having poly‐3‐hexylthiophene (P3HT) as complementary electrode. The prepared device gives high optical contrast (OC) (≈85%) and coloration efficiency (CE) (≈340 cm2 C−1) with ≈1 s of switching time in the visible spectrum at 515 nm. A similar color modulation is observed in NIR region also. Along with high electrochromic properties, the device takes almost 23.1 s for discharging and 6.7 s for charging, giving high Columbic efficiency due to the pseudocapacitor‐type charge storage property providing necessary electrons for the redox reaction to occur. The current study proposes a new MXene‐based recipe for designing multifunctional electrochromic supercapacitors with a promise for practical use.

3,6-Dimethoxythieno[3,2-b]thiophene-Based Bifunctional Electrodes for High-Performance Electrochromic Supercapacitors Prepared by One-Step Electrodeposition.

An integrated visual energy system consisting of conjugated polymer electrodes is promising for combining electrochromism with energy storage. In this work, we obtained copolymer bifunctional electrodes poly(3,6-dimethoxythieno[3,2-b]thiophene-co-2,3-dihydrothieno[3,4-b][1,4]dioxin-3-ylmethanol)(P(TT-OMe-co-EDTM)) by one-step electrochemical copolymerization, which exhibits favorable electrochromic and capacitive energy storage properties. Because of the synergistic effect of PTT-OMe and PEDTM, the prepared copolymers show better flexibility. Moreover, the morphology and electrochemical properties of the copolymers could be adjusted by depositing different molar ratios of 3,6-dimethoxythieno[3,2-b]thiophene (TT-OMe) and 2,3-dihydrothieno[3,4-b][1,4] dioxin-3-ylmethanol (EDTM). The P(TT-OMe-co-EDTM) electrodes realized a high specific capacitance (190 F/g at 5 mV/s) and recognizable color conversion. This work provides a novel and simple way to synergistically improve electrochromic and energy storage properties and develop thiophene-based conducting polymers for electrochromic energy storage devices.

Direct Observation of Reversible Surface Potential in Pseudocapacitive Electrochromic Films by Kelvin Probe Force Microscopy

High-resolution topography and local potential images together are very powerful tools for understanding the local environment of nanomaterials. In electrochemistry, there are significant changes within the electrode materials upon charging and discharging. However, the surface changes for pseudocapacitive materials in repetitive electrochemical cycling are easily being overlooked. Thanks to the advances in Atomic Force Microscopy, it becomes feasible to visualize the electrical changes in surface upon charge transfer with Kelvin Probe Force Microscopy (KPFM) equipped with a conductive tip. We report the KPFM surface potential images and profiles of NiO electrochromic films upon bleaching (charging) and coloration (discharging). The measured surface potential is about 60 times higher in bleaching state upon charging at 20mC/cm2. What is interesting is that the potential profile shows identical topographic features with the height profile of surface morphology. The surface particles further demonstrate shape entanglement in one direction (from ~100nm to ~140nm) and shrinkage in the orthogonal direction, suggesting the charge-induced electrical stress. According to the pseudocapacitive features in the cyclic voltammetry and electrochemical impedance spectroscopy, the surface-dominant redox behavior is within expectation. Though, this dynamic surface potential change is not well studied but important, and associated with work function fluctuations and various kinds of nanoscale charge-sensitive properties, especially for efficient electrochromic supercapacitor energy storage.

Copper Vanadium Oxide Yolk-Shell Microspheres with Excellent Capacitance and Cycling Performance for Electrochromic Supercapacitor.

Vanadium pentoxide (V2O5) is considered a promising material for electrochromic supercapacitors due to its rich color transitions and excellent electrochemical capacity. However, V2O5 exhibits low electrical conductivity, and its volume changes dramatically during charge-discharge cycles, leading to structural collapse and poor long-term cyclability. These issues have hindered the development and application of V2O5. In this study, copper vanadium oxide yolk-shell microspheres (CVO) were synthesized through a one-step solvent heat treatment with an annealing process. With the doping of copper element, the capacitance, conductivity, and cyclic stability of CVO microspheres were significantly enhanced. Subsequently, the sphere-wire network structure was formed by blending Na2V6O16·3H2O nanowires (NVO), resulting in the formation of CVO/NVO composites. The three-dimensional sphere-wire network efficiently facilitates the acquisition of additional redox sites and strengthens the material-to-substrate bonding. Under the combined influence of these favorable factors, CVO/NVO achieved a high specific capacitance of 39.2 mF cm-2, with a capacitance retention of 84% after 7500 cycles at a current density of 0.7 mA cm-2. The fully inorganic solid-state electrochromic supercapacitor (ECSC), assembled on the basis of CVO/NVO, demonstrates a vivid and clearly distinguishable color change (ΔE* = 37). Even more impressive is the energy storage capacity (18.4 mF·cm-2) and the cycling stability (up to 89% retention after 10,000 cycles) exhibited by the devices. These key performances are superior to those of most of the previously reported V2O5-based ECSCs, opening a promising avenue for the development of V2O5-based electrochromic energy storage devices.

Silver nanowires/WO3 quantum dots electrode with enhanced vertical electric field gradient for Al3+/Li+ dual-functional electrochromic supercapacitor

Dual-functional electrochromic supercapacitors (DECSs), which demonstrate the substantial potential for reversible changes in optical properties and energy storage capabilities, hold considerable promise for a wide range of applications in areas such as smart windows, displays, and wearable electronics. Nevertheless, challenges still exist in effectively optimizing their capacitance, ensuring cycling stability, and achieving cost-effective fabrication. Herein, this study explores an approach by integrating Al3+ and Li+ ions as hybrid electrolyte to enhance electrochemical activity. Utilizing WO3 quantum dots (WQDs) embedded within Ag nanowires (Ag NWs) grids offers a promising strategy to augment the vertical electric field gradient and prevent the self-agglomeration of WQDs. In addition, the integration of hybrid electrolyte comprising Al3+ and Li+ ions not only enhance electrochemical activity but also serves to mitigate the high-cost lithium sources. The resulting Ag NWs/WQDs electrode exhibits an impressive specific capacitance of 681.6 F g−1 at 0.25 mA cm−2 in Al3+/Li+ hybrid electrolyte, a notable 5-fold increase compared to the pristine WQDs electrode in Li+ electrolyte (139.3 F g−1). Simultaneously, this dual-function electrode demonstrates a large optical modulation (81.8 % at 700 nm), a fast switching-speed (tbleaching=7 s, tcoloring=5 s), and a long cycling life (maintaining 84.6 % of its original capacitance after 5000 cycles). Noteworthy insights from COMSOL simulations highlight the Ag NWs grid's "conductive bridge" function, which shows a positive attribution in optimizing the vertical electric field gradient. As a demonstration of proof-of-concept, a large-size flexible dual-functional electrochromic supercapacitor (DECS, 15 cm×10 cm) confirms energy-saving and storage dual-functionality device. Typically, the DECS-equipped inner room experiences a temperature 10°C lower than that of a room with a blank PET within 10 min, indicating the significant irradiation shielding. In addition, this device exhibits a remarkable specific capacitance of 9.25 mF cm−2 at 5 mV s−1, accompanied by an exceptional stability under simulated solar irradiation. The innovation of 0D/1D hierarchical structure of the electrodes together with the hybrid electrolyte not only reduce costs but also enhance the capacitance and cycle stability of DECSs, offering new insights for the development of next-generation flexible electronic wearables.

Comparative Study of Electrochromic Supercapacitor Electrodes Based on PEDOT:PSS/ITO Fabricated via Spray and Electrospray Methods.

PSS stands out as a leading commercial conducting polymer due to its excellent water dispersibility, controllable miscibility, adjustable conductivity, and ability to form films through various techniques. This study investigates the electrochemical and electrochromic performance of electrodes prepared by depositing PEDOT:PSS onto ITO surfaces by using two distinct methods: conventional spray coating and electrospray deposition. Detailed characterization of the prepared electrodes was performed by using atomic force microscopy, scanning electron microscopy, Fourier-transform infrared, and Raman spectroscopy techniques. Our findings reveal that electrodes fabricated via electrospray deposition (PEDOT:PSS/ITO electrode_2) significantly outperform those made by spray coating (PEDOT:PSS/ITO electrode_1). Specifically, electrode_2 exhibits a capacitance of 1678.60 μF cm-2, compared to 826.14 μF cm-2 for electrode_1, at a current density of 10 μA cm-2. PSS electrodes exhibit areal energy densities of 0.41 and 0.84 mW h cm-2, along with power densities of 4.96 and 4.97 μW cm-2, respectively. Moreover, electrode_2 demonstrates a high coloration efficiency of 84.32 cm2 C-1 and fast response times of 1.36 s for coloration and 0.98 s for bleaching. This study highlights the advantages of electrospray deposition over traditional methods, showcasing the potential of electrospray-prepared PEDOT:PSS electrodes for use in multifunctional energy storage devices.

Electrochemical and impedance analysis of nickel oxide nanoflakes-based electrodes for efficient chromo supercapacitors

In response to the dynamic advancement of our growing world, there is a tenacious need for sophisticated technologies and continuous refinement of existing knowledge through rigorous scientific endeavors, all with a focus on achieving sustainable development goals for a cleaner and more prosperous future. In this context, this study involves a novel approach to the synthesis of highly porous and stable nickel oxide (NiO) nanoflakes assembled with stacked nanosheet thin films through hydrothermal methods. These films are in-detail examined for their redox-active chromo-supercapacitive properties. The hydrothermal synthesis technique yields thin films with exceptional adhesion to the electrode surface, remarkable chemical stability, and suitable porous structure. These characteristics are strategically employed to facilitate rapid ion intercalation and deintercalation processes, thereby enhancing electrochemical activity. Notably, films deposited for 6-hour reaction times deliver a higher areal capacitance of 140 mF/cm² (and capacity of 70 mC/cm2) at 0.5 mA/cm², which is higher than other electrodes and earlier reports. In-situ, optical investigations further underscore the high coloration efficiency of 44.14 cm²/C, coupled with large optical modulation of 56.5 % and enduring the electrochemical and electrochromic stability. Further research and optimization of NiO-based materials hold significant potential for the development of efficient, smart, and sustainable energy storage solutions in the evolving field of electrochromic supercapacitors to meet the demands of next-generation electronic systems.

All-in-one flexible paper-based self-powered energy and display system employing complementary properties of printed PEDOT:PSS/PANI:PSS dual-electrode with a dual-sided triboelectric nanogenerator

A Self-powered energy and display system (SPEDS) has been developed by integrating functionalities of energy harvesting, storage, and multicolor display, heralding innovative solutions for integrated electronic devices. An all-in-one multi-information SPEDS is proposed through incorporating a multicolor electrochromic supercapacitor device (ESCD) with a dual-sided triboelectric nanogenerator (TENG), all screen-printed on a paper substrate. The synergistic enhancement in the conductive, capacitive, and electrochromic performance is realized by exploiting the complementary properties of PEDOT:PSS/PANI:PSS to form a simplified structure of ESCD, in which the electrode and electrochromic layers are integrated into one shared layer, resulting in a wide color gamut and an enhanced capacitive performance of 3.4 mF/cm². Electrochromic electrodes having identical composition exhibit independent color changes at the anode and cathode, thereby featuring a combined color display indicating multi energy-related information. Moreover, the conductive layer fabricated through patterned printing on the paper substrate, serves as both the electrode layer for TENG and the interconnect circuitry with the prepared ESCD. Furthermore, a double-sided TENG was realized by exploiting the triboelectric properties of the paper substrate and then a self-powered energy display wristband was constructed, exemplifying a novelty application utilizing the multi-information indicator properties for energy display derived from the dual-sided friction power generation.

Smart Energy Storage: W18O49 NW/Ti3C2Tx Composite-Enabled All Solid State Flexible Electrochromic Supercapacitors.

Developing a highly efficient electrochromic energy storage device with sufficient color fluctuation and significant electrochemical performance is highly desirable for practical energy-saving applications. Here, to achieve a highly stable material with a large electrochemical storage capacity, a W18O49 NW/Ti3C2Tx composite has been fabricated and deposited on a pre-assembled Ag and W18O49 NW conductive network by Langmuir-Blodgett technique. The resulting hybrid electrode composed of 15 layers of W18O49 NW/Ti3C2Tx composite exhibits an areal capacitance of 125mFcm-2, with a fast and reversible switching response. An optical modulation of 98.2% can be maintained at a current density of 5mAcm-2. Using this electrode, a bifunctional symmetric electrochromic supercapacitor device having an energy density of 10.26µWhcm-2 and a power density of 0.605mWcm-2 is fabricated, with high capacity retention and full columbic efficiency over 4000 charge-discharge cycles. Meanwhile, the device displays remarkable electrochromic characteristics, including fast switching time (5s for coloring and 7s for bleaching), and a significant coloration efficiency of 116cm2C-1 with good optical modulation stability. In addition, the device exhibits significant mechanical flexibility and fast switching while being stable over 100 bending cycles, which is promising for real-world applications.

Metal oxide-mixed polymer-based hybrid electrochromic supercapacitor: improved efficiency and dual band switching

The inclusion of charge storage properties in electrochromic devices (ECDs) has gained much interest and has evolved into a promising emerging energy-related field due to multifunctional smart device applications. Here, an organic–inorganic solid-state asymmetric electrochromic supercapacitor device (ESCD) containing nano-CoTiO3-mixed poly-3-hexylthiophene and WO3 as two electrodes has been designed to study electrochromic and supercapacitor properties. The electrochemical properties of CoTiO3 show a pseudocapacitive-type charge storage capability, which has been utilized to enhance the electrochromic performance of the ESCD with additional charge storage ability. The device shows charge storage properties with fast charging and slow discharging, giving very high coulombic efficiency with a specific capacitance of 6.4 mF cm−2 at 0.2 mA cm−2 current density. The device shows excellent electrochromic supercapacitive properties with a color contrast of ∼50% and a short switching time of ∼1 s at a 515 nm wavelength with excellent cyclic stability. The device exhibits the capability to cut near infrared wavelength (700 nm and 850 nm) and has a potential application as a heat filtering device. Thus, the addition of pseudocapacitive-type materials in ECDs enhances the capacitive performance along with electrochromic properties, which makes ECDs more suitable for real life applications.

One-step achieving high performance all-solid-state and all-in-one flexible electrochromic supercapacitor by polymer dispersed electrochromic device strategy

Electrochromic devices (ECD) are widely used to regulate the transmittance of sunlight by applying a small voltage, but the drawbacks like complex layer-by-layer preparation procedures and inconvenient assembling process still exist. To address these problems, gel or solution-type all-in-one ECDs were recently developed for the simple structure, however, the leakage risk and absence of flexible large-area production have limited real applications. Herein, a novel all-solid-state and all-in-one flexible ECD was reported by originally developed polymer dispersed electrochromic device (PDECD) strategy. This all-solid-state flexible ECD could be efficiently prepared only by one step of phase separation without any extra treatment, and demonstrated outstanding stability (92.1 % of original ΔT remained after 10,000 cycles), high coloration efficiency (197 cm2/C), low power consumption (86.4 μW/cm2) and satisfied response time (≤12 s). Meanwhile, the stored power in ECD during coloring process could drive a LED with excellent cyclic stability (93 % of original capacity remained after 3000 cycles), implying that ECD could also serve as an idea electrochromic supercapacitor. What’more, a reported largest viologen-based all-solid-state flexible ECD (17.8 × 13.2 cm2) with robust bending resistance (up to 1000 bending cycles) was successfully fabricated with industrial roller coating technique, which indicated the huge potential in real world.

Stoichiometrically Optimized Electrochromic Complex [V2O2+ξ(OH)3-ξ] Based Electrode: Prototype Supercapacitor with Multicolor Indicator.

The systematic structure modification of metal oxides is becoming more attractive, and effective strategies for structural tunning are highly desirable for improving their practical color-modulating energy storage performances. Here, the ability of a stoichiometrically tuned oxide-hydroxide complex of porous vanadium oxide, namely [V2O2+ξ(OH)3-ξ]ξ = 0:3 for multifunctional electrochromic supercapacitor application is demonstrated. Theoretically, the pre-optimized oxide complex is synthesized using a simple wet chemical etching technique in its optimized stoichiometry [V2O2+ξ(OH)3-ξ] with ξ=0, providing more electroactive surface sites. The multifunctional electrode shows a high charge storage property of 610Fg-1 at 1Ag-1, as well as good electrochromic properties with high color contrast of 70% and 50% at 428 and 640nm wavelengths, faster switching, and high coloration efficiency. When assembled in a solid-state symmetric electrochromic supercapacitor device, it exhibits an ultrahigh power density of 1066mWcm-2, high energy density of 246mWhcm-2, and high specific capacitance of 290mFcm-2 at 0.2mAcm-2. A prepared prototype device displays red when fully charged, green when half charged, and blue when fully discharged. A clear evidence of optimizing the multifunctional performance of electrochromic supercapacitor by stoichiometrical tuning is presented along with demonstrating a device prototype of a 25cm2 large device for real-life applications.

Electrodeposited Tungsten Trioxide (WO3) Thin Films for Electrochromic Applications

The need of smart and innovative technology with energy saving approach is the main and serious concern while dealing with fastest growing urbanization and civilization. The smart technologies like electrochromic supercapacitors are beneficial in multifunctional way by providing energy storage systems with visual and reversible colour changes in many applications such as smart windows, electrochromic goggles, automotive mirrors, sunroofs, displays and so on. Herein, nanoporous WO3 thin film is prepared by using cathodic electrodeposition technique and used to study electrochromic as well as electrochemical properties. The bi-functionality of the electrode was confirmed by electrochemical tests including CV, GCD, EIS and chrono methods. The film shows greater coloration efficiency up to 52.61 cm2/C with an aerial capacitance 2.8 mF /cm2. Also, film shows faster switching kinetics as faster coloration and bleaching times like 1.88 and 2.6 s respectively. Hence, electrodeposited WO3 can be a good candidate for bi-functional electrochromic supercapacitors.

Electrode materials for electrochromic supercapacitors.

Smart energy storage systems, such as electrochromic supercapacitor (ECSC) integrated technology, have drawn a lot of attention recently, and numerous developments have been made owing to their reliable performance. Developing novel electrode materials for ECSCs that embed two different technologies in a material is an exciting and emerging field of research. To date, the research into ECSC electrode materials has been ongoing with excellent efforts, which need to be systematically reviewed so that they can be used to develop more efficient ECSCs. This mini-review provides a general composition, main evaluation parameters and future perspectives for electrode materials of ECSCs as well as a brief overview of the published reports on ECSCs and performance statistics on the existing literature in this field.

Self-Powered Dual-Band Electrochromic Supercapacitor Devices for Smart Window Based on Ternary Dielectric Triboelectric Nanogenerator.

A dual-band electrochromic supercapacitor device (DESCD) can be driven by an external power supply to modulate solar radiation, which is a promising energy-saving strategy and has broad application prospects in smart windows. However, traditional power supplies, such as batteries, supercapacitors, etc., usually face limited lifetimes and potential environmental issues. Hence, we propose a self-powered DESCD based on TiO2/WO3 dual-band electrochromic material and a ternary dielectric rotating triboelectric nanogenerator (TDR-TENG). The TDR-TENG can convert mechanical energy from the environment into electrical energy to obtain a high output of 840 V, 23.9 µA, and 327 nC. The as-prepared TDR-TENG can drive the TiO2/WO3 film to store energy with a high dual-band modulation amplitude of 41.6% in the visible (VIS) region and 84% in the near-infrared (NIR) region, decreasing the indoor-outdoor light-heat interaction and thereby reducing the building energy consumption. The self-powered DESCD demonstrated in this study has multiple functions of energy harvesting, energy storage, and energy saving, providing a promising strategy for the development of self-powered smart windows.

Non-conjugated electrochromic supercapacitors with atom-economic arylamine-based AB2-polyamides

A highly atom-economic AB2-type hyperbranched polyamide, HPA-TPA, was judiciously designed and prepared. HPA-TPA showed remarkable electrochromic behaviours and charge–discharge characteristics with the aid of the hyperbranched architecture.

Design Strategies for High Reflectivity Contrast and Stability Adaptive Camouflage Electrochromic Supercapacitors.

The integration of an electrochromic (EC), energy storage, and adaptive camouflage system into a multifunctional electronic device is highly desirable and yet challenging. In this work, two carbazole-based conjugated polymers were prepared to achieve a reversible color change from transparent to yellow, green, and blue-green by easy electrochemical polymerization. Due to its dendritic geometry, the conjugated polymer p3CBCB exhibits a loosely packed structure with a relatively higher specific surface area than pCBCB, as well as a relatively better ionic conductivity. The kinetic and galvanostatic charge-discharge (GCD) study reveals that p3CBCB has superior properties with larger optical contrast and volumetric capacitance. Moreover, EC supercapacitors (ECSCs) are constructed with p3CBCB as the EC layer and ZnO@PEDOT:PSS as the ion storage layer. The dual function of a ZnO interface layer on improvement in reflectivity contrast (ΔR% > 35.1%) and cycling stability (over 40,000 cycles) using ZnO as a reflective and protective layer is demonstrated in an ion storage layer. Additionally, patterned prototype devices based on the design of double-sided ITO glass were successfully assembled, which can simulate conditions of various natural environments including forests, wilderness, and deserts. This study provides new ideas not only for the preparation of conjugated polymers that can simultaneously realize reversible transparent-yellow-green conversion but also for the achievement of high coloration efficiency, high reflectivity contrast, and good stability of ECSCs for adaptive camouflage.

Portable Visual Photoelectrochemical Biosensor Based on a MgTi2O5/CdSe Heterojunction and Reversible Electrochromic Supercapacitor for Dual-Modal Cry1Ab Protein Detection.

Reversible electrochromic supercapacitors (ESCs) have attracted considerable interest as visual display screens. The use of ESCs in combination with a photoelectrochemical (PEC) biosensor promises to improve the detection efficiency. Herein, a visual PEC biosensor is developed by introducing a circuit module between a PEC-sensing platform (PSP) and a reversible ESC for Cry1Ab protein detection. In PSP, a type II MgTi2O5/CdSe heterojunction effectively drives charge separation by their cross-matched band gap structures, generating an amplified photocurrent. Next, the circuit module is designed to connect the PSP and ESC, realizing the signal conversion from photocurrent to voltage. ESC, as a visual display screen, produces reversible color changes with different voltages. As the concentration of Cry1Ab increases, the photocurrent decreases due to the specific binding between the aptamer and Cry1Ab in PSP, while the color of the reversible ESC changes from green to blue. To improve the integrity of the device, a portable PEC biosensor is further constructed via three-dimensional printing for dual-modal Cry1Ab protein detection, thus collecting both PEC and visual signals. The linear ranges are 0.3-3000 ng mL-1 for PEC mode and 1-1000 ng mL-1 for visual mode. This work presents a portable, efficient, sensitive, and visualized detection system, providing an important reference for practical visualization applications.

Highly color tunable, electrochromic energy storage devices based on dye-modified ion gels

In this work, we proposed a facile strategy to achieve high color tunability of electrochromic supercapacitors (ECSs) with tungsten trioxide (WO3) and nickel oxide (NiO) combination as EC materials. To achieve high color tunability, we applied a small amount of rhodamine (1:103 wt%) as dyes and achieved a wide color map (e.g. blue, yellowish, and magenta). Hence, to expand the color map, we mixed dyes, controlled the concentration of dyes, and controlled the ratio of dye solutions therefore successfully expanding the color map (e.g. purple, navy, and red) and including highly reliable charging/discharging cyclic stability (83.6 % after 10,000 cycles), change in transmittance and galvanostatic charging/discharging curve synchronized well simultaneously and therefore energy storage amount is indicated visually For last, we fabricated practical feasibility of multicolor ECSs successfully. ECSs in this work have the potential to be ECSs applications for the next generation of smart windows as energy storage displays.