Enhanced Ni–Co redox dynamics in dual-SDA engineered ZIF-67 derivatives for high-performance supercapacitors: Insights from operando X-ray spectroscopy
Journal
Composites Part B: Engineering
Journal Volume
304
Start Page
112646
ISSN
1359-8368
Date Issued
2025-09
Author(s)
Dung, Shen-Fa
Cheshideh, Hamed
Lee, Pin-Yan
Tu, Kun-Hua
Chen, Hung-Ming
Wu, Yung-Fu
Chen, Hsiao-Chien
Lin, Lu-Yin
Abstract
The development of high-performance supercapacitor electrodes demands novel synthesis methods to precisely control the properties of the active material. Here, we report an advanced one-step approach that employs ammonium hydrogen fluoride (NH4HF2) and ammonium tetrafluoroborate (NH4BF4) as dual-structure directing agents (SDAs) to develop novel zeolitic imidazolate framework-67 (ZIF-67) derivatives (ZIF-HB), with cobalt and nickel hydroxides as the main components. Modulation of the NH4HF2/NH4BF4 molar ratio results in significant changes to the morphology, surface and electronic configurations, and electrochemical behavior. The optimized ZIF-HB (ZIF-HB12) electrode delivers impressive electrochemical performance, achieving a high specific capacitance (CF) of 1933.3 F/g at 20 mV/s. It is revealed from advanced structural analyses, including operando X-ray absorption spectroscopy that the redox reactivity and charge transfer dynamics are considerably boosted as a result of synergistic interactions between Co and Ni sites. An asymmetric supercapacitor (SC) assembled using ZIF-HB12 shows maximum energy density of 19 Wh/kg at 1143 W/kg, with a CF retention of 81.3% and a Coulombic efficiency of 97.2% after 10,000 cycles. This study highlights the effectiveness of dual-function SDAs in designing structurally robust, electrochemically active, and electronically optimized electrode materials for cutting-edge energy storage solutions.
Subjects
Dual SDAs
Energy storage
Operando XAS
Redox dynamics
Supercapacitors
ZIF-67
Publisher
Elsevier BV
Type
journal article