Mesoporous NiO nanoarchitectures for electrochemical energy storage: Influence of size, porosity, and morphology

The development of flexible, sustainable, and efficient energy storage has recently attracted considerable attention to satisfy the demand for huge energy and power density and meet future societal and environmental needs. Consequently, numerous studies have focused on the design/development of nanomaterials based on mesoporous architectures to improve energy and power densities. We explored how nanoarchitectures in term of morphology, particle size, surface area, and pore size/distribution define energy and power performance. The large-scale production, low-cost manufacturing, and high-performance of supercapacitors based on the microwave-assisted synthesis of mesoporous nickel oxide nanocrystals (NCs) were presented. Mesoporous NiO in various morphologies including nanoslices (NSs) and nanoplatelets (NPLs), were synthesized. The superior electrochemical performance of mesoporous NiO NPLs is related to their unique morphology, size, and pore size distribution, which enhance the diffusion of hydroxide ions through mesoporous networks, i.e. "superhighways". These characteristics induce the high capacitance and excellent recyclability of NiO NPLs more than NiO NSs. Moreover, the microwave-assisted synthesis enhanced charge storage and stability compared with those prepared through the hydrothermal approach. This approach demonstrates the potential of free-standing NiO NPL electrodes for developing high-performance pseudocapacitors.