Hierarchical NiMn-LDH Hollow Spheres as a Promising Pseudocapacitive Electrode for Supercapacitor Application

Jai Kumar; Rana R Neiber; Zaheer Abbas; Razium Ali Soomro; Amal BaQais; Mohammed A Amin; Zeinhom M El-Bahy

doi:10.3390/mi14020487

Hierarchical NiMn-LDH Hollow Spheres as a Promising Pseudocapacitive Electrode for Supercapacitor Application

Micromachines (Basel). 2023 Feb 19;14(2):487. doi: 10.3390/mi14020487.

Authors

Jai Kumar¹, Rana R Neiber^{1

2}, Zaheer Abbas³, Razium Ali Soomro⁴, Amal BaQais⁵, Mohammed A Amin⁶, Zeinhom M El-Bahy⁷

Affiliations

¹ College of Chemical Engineering, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
² Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green, Process, and Engi-neering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
³ Metallurgy and Materials Engineering Department, University of Engineering and Technology, Taxila 47050, Pakistan.
⁴ State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing 100029, China.
⁵ Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
⁶ Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
⁷ Department of Chemistry, Faculty of Science, Al-Azhar University, Nasr City 11884, Cairo, Egypt.

Abstract

Layered double hydroxides (LDH) are regarded as attractive pseudocapacitive materials due to their impressive capacitive qualities that may be adjustable to their morphological features. However, the layered structure of LDH renders them susceptible to structural aggregation, which inhibits effective electrolyte transport and limits their practical applicability after limited exposure to active areas. Herein, we propose a simple template-free strategy to synthesize hierarchical hollow sphere NiMn-LDH material with high surface area and exposed active as anode material for supercapacitor application. The template-free approach enables the natural nucleation of Ni-Mn ions resulting in thin sheets that self-assemble into a hollow sphere, offering expended interlayer spaces and abundant redox-active active sites. The optimal NiMn-LDH-12 achieved a specific capacitance of 1010.4 F g^-1 at a current density of 0.2 A g^-1 with capacitance retention of 70% at 5 A g^-1 after 5000 cycles with lower charge transfer impedance. When configured into an asymmetric supercapacitors (ASC) device as NiMn-LDH//AC, the material realized a specific capacitance of 192.4 F g^-1 at a current density of 0.2 A g^-1 with a good energy density of 47.9 Wh kg^-1 and a power density of 196.8 W kg^-1. The proposed morphological-tuning route is promising for designing template-free NiMn-LDHs spheres with practical pseudocapacitive characteristics.

Keywords: hollow spheres; layer double hydroxide; ssupercapacitors.

Grants and funding

This research work was funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2023R230), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.