All‐Solid‐State Deformable Hybrid Supercapacitor Based on Porous Self‐Phosphorus‐Doped Bio‐Carbon as a Cathode and MXene‐Modified Doped Metal Oxide as an Anode

Deformable all-solid-state energy storage systems are grabbing significant interest; however, the simultaneous acquisition of high stability alongside high power and energy densities for user-oriented portable electronics remains a daunting challenge. Thus, hybridizing battery and capacitor materials offers a prospective strategy toward efficiently bridging the performance gap between high-energy batteries and high-power supercapacitors. In this work, an all-solid-state deformable hybrid supercapacitor (ADHS) utilizing interfacially coupled in situ carbon-doped zinc cobaltite/MXene (MCZ) as anode and porous self-phosphorus-doped bio-carbon (TAC) derived from Averrhoa carambola leaves as the cathode is presented. The anode delivers high energy via battery-type storage, while the porous cathode ensures stable, high-power output over a broad potential window. The ADHS exhibits a specific capacitance of 124.13 F g^-1, energy density of 119.16 Wh kg^-1, and power density of 3139.53 W kg^-1, with 90.55% initial capacitance retention post 20 000 cycles, outperforming or matching state-of-the-art storage devices. Furthermore, the device maintains electrochemical stability under 100 deformation cycles and various twisting angles, highlighting its promise for next-generation energy storage applications.