A LiPF6 gel-polymer electrolyte for a solid-state supercapacitor with polyaniline/MnCo layered double hydroxide nanosheets as active electrode material

Abstract

This paper introduces a novel solid-state electrolyte for supercapacitors (SCs), employing a LiPF6 gel polymer coupled with innovative electrodes composed of MnCo-layered double hydroxide (LDH) nanosheets. The newly synthesized LiPF6 gel polymer electrolyte exhibits superior ionic conductivity and mechanical flexibility, making it an ideal candidate for advanced energy storage devices that require bending and twisting capabilities. The thermal analyses and morphological characterizations were evaluated using DSC, XRD, FT-IR, BET, TEM and FE-SEM techniques. The MnCo-LDH nanosheets, synthesized via a facile co-precipitation method, served as the electrode material. It was expected that the collaborative interaction between the LiPF6 polymer matrix and the multifaceted nanoflower-shaped MnCo-LDH nanosheets could improve electron mobility and supply an increased surface area for redox processes. Electrochemical analyses, including cyclic voltammetry and galvanostatic charge-discharge tests, reveal a marked improvement in the specific capacitance, rate capability, and cyclic stability of the assembled SCs. This novel electrolyte-electrode configuration yielded a specific capacity of up to 198.66 F g−1 at 1.6 A g−1 and exhibited rate performance with retention of 89.15 % at an elevated current density of 10 A g−1 for 2-Hydroxyehtyl cellulose: LiPF6 gel polymer with molar ratio of 1: 2. Moreover, it demonstrates enduring cyclic stability with no capacity decay after 10,000 cycles. We delineated the pivotal role of Mn in facilitating electron transfer kinetics and moderating interactions with Co ions. The introduction of strain within the LDH structure promulgates a conducive environment for electrochemical reactions.