Yong Zhang

Layered double hydroxides (LDHs) show considerable potential as pseudocapacitive materials for supercapacitors; however, their electrical conductivity and cycling stability remain critical challenges for enhancing overall performance. In this study, pure CoFe-LDH and its composite series with activated carbon (AC) were successfully fabricated on nickel foam substrates via a hydrothermal method. The effects of AC addition on the microstructure and electrochemical behavior of the materials were systematically investigated using characterization techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results demonstrate that the composite material CoFe-LDH/AC[Formula: see text], prepared with an AC dosage of 15[Formula: see text]mg, exhibits the most outstanding energy storage performance: a specific capacitance of 3993 Fg[Formula: see text] at a current density of 1 Ag[Formula: see text], representing a 47.2% improvement compared with pure CoFe-LDH (2713 Fg[Formula: see text]); furthermore, the capacity retention remains at 77.9% even at a high current density of 10 Ag[Formula: see text], indicating excellent rate capability. The cycling durability test shows that the electrode material retains 42% of its initial capacitance after 5000 charge/discharge cycles at a current density of 5 Ag[Formula: see text]. This study confirms that the synergistic enhancement between AC and CoFe-LDH significantly improves the electrical conductivity and structural stability of the composite materials, effectively boosting the overall electrochemical performance, which holds important significance for the development of high-performance supercapacitor electrode materials.

To enhance the electrochemical performance of NiMn‐LDHs electrode materials, this study explores metal Co doping and synthesizes nano‐onion‐like NiCoMn‐LDHs composites. By examining the effects of various heat treatment temperatures (100°C, 110°C, 120°C, 130°C, and 140°C), we identified that NiCoMn‐LDHs prepared at 130°C exhibited superior performance. The results reveal that Co doping significantly increases the specific capacitance compared with undoped NiMn‐LDHs. The 130°C NiCoMn‐LDHs achieved a specific capacitance of 4413 F g ¹ at 1 A g ⁻¹ and maintained 3055 F g ⁻¹ at 10 A g ⁻¹ , demonstrating excellent rate performance. These findings highlight the benefits of Co doping and optimized heat treatment for improving NiMn‐LDHs in supercapacitor applications, providing a strong foundation for their use in high‐performance energy storage devices.

This study aims to enhance the performance of supercapacitors, focusing particularly on optimizing electrode materials. While pure NiMn layered double hydroxides (LDHs) exhibit excellent electrochemical properties, they have limitations in achieving high specific capacitance. Therefore, this paper successfully synthesized composite materials of NiMn LDHs with varying loadings of graphene oxide (GO) using a hydrothermal method. Systematic physicochemical characterization of the synthesized materials, such as powder X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), field‐emission scanning electron microscopy (FE‐SEM), and Raman spectroscopy, revealed the influence of GO doping on the microstructure and electrochemical performance of NiMn LDHs. Electrochemical tests demonstrated that the NiMn LDHs/GO electrode material exhibited optimal electrochemical performance with a specific capacitance of 2096 F g⁻¹ at 1 A g⁻¹ current density and 1471 F g⁻¹ at 10 A g⁻¹, when GO doping level was 0.45 wt %. Furthermore, after 1000 cycles of stability testing, the material retained 53.3 % capacitance at 5 A g⁻¹, indicating good cyclic stability. This study not only provides new directions for research on supercapacitor electrode materials but also offers new strategies for developing low‐cost and efficient electrode materials.