Organophosphorus ligand-assisted layered metal phosphonates as flexible electrode materials for high-performance interdigital micro-supercapacitors

In designing high-performance asymmetric supercapacitor (ASC) devices, the morphology of the materials is a crucial factor for an efficient ion diffusion process. The following describes the non-templating synthesis of three distinct microporous metal phosphonates using organophosphorus ligands, including nickel phosphonate (NiBPA), cobalt phosphonate (CoBPA), and nickel cobalt phosphonate (NiCoBPA), Because of the higher surface area, microporous structure, and the unique layered morphology of NiCoBPA, it exhibits excellent charge transfer ability. NiCoBPA depicts the outstanding capacitance value of 3537 F g⁻¹. The ASC coin-cell device has been designed using NiCoBPA as the cathode material. It displays an energy density (ED) of 113.6 W h Kg⁻¹ at a power density (PD) of 990.3 W kg⁻¹ with long-period stability. However, utilizing compact-size wearable and portable electronics in the present period permits the development of sustainable storage technology. So, an asymmetric micro-supercapacitor (AMSC) with a high degree of flexibility was fabricated. The AMSC device (NiCoBPA//AC) has been shown to power up various coloured light-emitting diodes (LEDs) with an exceptional areal capacitance of 137.2 mF cm⁻². The simple and rational pathway for synthesizing the high-performance, low-cost, effective AMSC device signifies the new direction to straightforwardly design modern wearable devices with great mechanical flexibility.