Ultra-high energy stored into multi-layered functional porous carbon tubes enabled by high-rate intercalated pseudocapacitance

Pseudo-supercapacitors have been pursued to realize high energy densities to compete with batteries. However, supercapacitor based on carbon fails to achieve the desired high energy density due to the surface oriented pseudocapacitive behavior. Here we report intercalated pseudocapacitive charge storage in carbon tubes derived from mushroom, which owns a unique morphology consisting of mesoporous, multi-layered, and functional architecture decorated with heteroatoms. This unique naturally gifted structure offers exceptional redox active sites than traditional carbons delivering high-rate pseudocapacitive behavior with the highest gravimetric and volumetric capacitances of 995 F g⁻¹ and 895 F cm⁻³ respectively. Additionally, stable and remarkable volumetric energy densities of 198 Wh L⁻¹ at 560 W L⁻¹ in an ionic electrolyte and 26 Wh L⁻¹ at power density of 2–200 kW L⁻¹ in an aqueous electrolyte are achieved. Overall, this investigation highlights a novel avenue for emerging next generation of sustainable high-performance energy storage devices.