Hierarchical SnO2@PC@PANI composite via in-situ polymerization towards next-generation Li-ion capacitor by limiting alloying process with high energy, wide temperature performance, and cyclability

Abstract

Lithium-ion capacitors (LICs) are promising electrochemical energy storage devices with hybridization of the battery-type anode and capacitive-type cathode, bringing high energy density and high power density simultaneously in a single device. We report the extraction of activated carbon from the palmyra fruit, in-situ polymerization with polyaniline (PANI), and the making of different composite formulations with SnO2 to be used as anode for LIC with palmyra fruit-derived activated carbon (PC) as the cathode. The SnO2@PC@PANI electrode is restricted to 1 V vs. Li, which allows only the alloying reaction and eliminates the conversion process. An in-situ impedance study is performed to validate the formation and depletion of the solid electrolyte interface over the battery-type electrode upon cycling. Prior to the fabrication of the LIC, the SnO2@PC@PANI is electrochemically pre-lithiated. The fabricated LIC with balanced mass loadings exhibits a mesmerizing electrochemical performance with a maximum energy density of ∼175 Wh kg–1 at room temperature. The possibility of LIC in different climatic conditions is also analyzed by testing its electrochemical performance in different temperature conditions.