Intercalation pseudocapacitance of monolithic microporous carbon thin film scrolls and their battery type behavior

Abstract

A distinct signature of intercalation pseudocapacitance is observed in doped carbon microfilm at highly negative anodic potential by patterning (scrolling) a thin, porous carbon film. Prominent redox peaks appear in alkaline solutions, which can be assigned to cation intercalation into a functionalized structural carbon matrix. The pseudocapacitance, in addition to electric double layer (EDL) capacitance, aligns with experimentally obtained ultra-high volumetric (257.42 Fcm⁻³) and areal (3.8 Fcm⁻²) capacitance, as well as capacity (76.70 mAh.g⁻¹ at 10 mA current) with high mass loading of 5 mg. The assembled metal-free symmetric device delivers an energy density of 8.228 mWh cm⁻³ at a power density of 9.374 mW cm⁻³ at 0.25 mA with a higher cycle life. Innovation of this work have its origin in the synthesis process that simultaneously exploits membrane casting and template assisted process to achieve hierarchical interconnected pores useful for large mass transport and ion storage. Importance of such structures further deepens due to their unique ion intercalation ability inside numerous micro grooves, providing pseudocapacitance in addition to electric double layer capacitance (EDLC). The unique design of a long-range ordered porous 3D conductive scaffold, patterned 2D and non-tortuous ionic paths with robust electronic conductivity, interconnected hierarchical pores, and a higher specific surface area (1001 m²g^-1) are importance of as prepared thick electrode, that outperforms other carbon-based monolithic and 3D printed electrode systems to construct energy storage devices.