Lamellar structured Ni 3 P 2 O 8 : first-ever use to design 1.8 V operated flexible all-solid-state symmetric supercapacitor.

Increasing demand for microelectronic devices necessitates the development of highly flexible energy storage technologies with a wide operating voltage. Thus, flexible electrodes and their devices with the requisite mechanical and electrochemical characteristics have prime importance. In this regard, the present article demonstrates the feasibility of designing a flexible all-solid-state supercapacitor using a chemically grown Ni 3 P 2 O 8 lamellar microstructured electrode embedded with carboxy methyl cellulose-Na 2 SO 4 (CMC-Na 2 SO 4 ) gel electrolyte. The formed symmetric device impressively exhibited a maximum working voltage window of 1.8 V with a high specific energy of 44.7 W h kg -1 and specific power of 3.3 kW kg -1 along with prolonged cycle life. Also, the device's high deformation tolerance (95%) when bent at 170° with a flashing light-emitting diode (LED) working demonstration showcases its viability for advanced flexible energy storage applications.