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Recently, electrochromic and energy storage devices based on the intercalation of Al3+ ions have attracted much attention due to their low-cost, safe and environmentally friendly characteristics. However, Al3+ ions usually suffer from strong electrostatic interaction. Here we propose an adaptive material, hexagonal tungsten oxide nanorod arrays (h-WNRAs) with an ordered channel structure, which showed a good match with trivalent Al3+ ions. Due to the synergetic effect between aqueous Al3+ and h-WNRAs, the material displayed excellent electrochromic performance such as high optical modulation (81.5%), low response time (9 and 14 s at 660 nm), high coloration efficiency (149.9 cm2 C−1 at 800 nm), good reversibility (97.9%, 96.7% and 89.3% coulombic efficiency at 50, 20 and 2 mV s−1, respectively) and good cycling stability (90.6% and 80.0% charge retention after 1000 cycles at 50 and 20 mV s−1, respectively). Meanwhile, good capacitive performance including good specific capacitance (235.4 F g−1 at 1 A g−1 in a narrow potential window of −0.7–0 V), good rate capability (58.2% retention of specific capacitance and 79.4% retention of optical modulation at 10 A g−1 compared with their initial values at 1 A g−1) and long-term stability during charging/discharging processes (86.2% retention of specific capacitance after a galvanostatic test at 5 A g−1 for 4000 cycles) was also achieved. This kind of system, using safe and environmentally friendly aqueous solution as electrolyte solvent, cheap and resourceful Al3+ as the electrolyte ion, and ordered h-WNRAs as the electrochromic and capacitive material (ECM), provided a new thinking for the development of dual-functional electrochromo-supercapacitors for the future. [ABSTRACT FROM AUTHOR]

Dual-band electrochromic materials have attracted significant attention due to their ability to independently control sunlight and solar heat. However, these materials generally exhibit notable limitations, and the mechanisms for their dual-band independent regulation remain poorly understood. Here, the visible-NIR-independent regulation capabilities of hexagonal WO 3 (h-WO 3 ) are introduced for the first time. A structure-activity relationship that perfectly links the microscopic ion insertion sequence and cavity characteristics to the macroscopic dual-band electrochromic properties is established. The progressive ion intercalation process and the distinctive optical activity of the cavities are keys for enabling h-WO 3 to independently modulate "bright," "cool," and "dark" modes. Notably, h-WO 3 demonstrates superior dual-band electrochromic performance with a broadband full shielding effect from 550 to 2000 nm, achieving the widest full shielding band in dual-band electrochromic studies. Additionally, h-WO 3 shows a high discharge capacity of 270.9 mAh m - 2 at 0.25 A m - 2 , and requires only 49.1 and 209.7 mAh m - 2 to complete a full round-trip switch between "bright-cool" and "bright-dark" modes, respectively. The constructed device offers a dynamic temperature control range of up to 10.5 °C and supports a maximum voltage of 2.86 V, underscoring its considerable potential for practical applications and energy efficiency., (© 2024 Wiley‐VCH GmbH.)