Ni3P2O8 nanodots anchored multiwalled carbon nanotubes composite for flexible all-solid-state symmetric supercapacitor

Flexible solid-state supercapacitors embedded the fast charge rate of electric double-layer capacitive materials with high capacity pseudocapacitive type materials to exhibit better storage capacity and cycle life, hold great potential for portable microelectronic devices in the present days. Herein, we propose analogues state of the art through the facile solution synthesis of multi-walled carbon nanotubes decorated by Ni3P2O8 nanodots (Ni3P2O8/ MWCNT) on a flexible substrate for supercapacitor application. Designed composite benefits from inter component synergistic effects wherein redox-enriched Ni3P2O8 nanodots contribute 26-fold high-performance energy storage capability with reference to bare MWCNT, while MWCNT acts as a one dimensional conductive as well as mechanical support for Ni3P2O8 growth. The corresponding flexible all-solid-sate symmetric supercapacitor designed from carboxymethyl cellulose-Na2SO4 (CMC-Na2SO4) neutral gel electrolyte holds a maximum specific energy of 72.3 Wh kg-1 with a power density of 6.4 kW kg-1 across an extended voltage window of 1.8 V. In addition, the device's excellent deformation tolerance (103 % at mechanical bending of 170o) indicates promising potential for enhanced flexible energy storage.