Developing supermechanically resilient hard carbon materials that can quickly accommodate sodium ions is highly demanded in fabricating durable anodes for wearable sodium‐ion batteries. Here, an interconnected spiral nanofibrous hard carbon fabric with both remarkable resiliency (e.g., recovery rate as high as 1200 mm s−1) and high Young's modulus is reported. The hard carbon nanofabrics are prepared by spinning and then carbonizing the reaction product of polyacrylonitrile and polar molecules (melamine). The resulting unique hard carbon possesses a highly disordered carbonaceous structure with enlarged interlayer spacing contributed from the strong electrostatic repulsion of dense pyrrolic nitrogen atoms. Its excellent resiliency remains after intercalation/deintercalation of sodium ions. The outstanding sodium‐storage performance of the derived anode includes excellent gravimetric capacity, high‐power capability, and long‐term cyclic stability. More significantly, with a high loading mass, the hard carbon anode displays a high‐power capacity (1.05 mAh cm−2 at 2 A g−1) and excellent cyclic stability. This study provides a unique strategy for the design and fabrication of new hard carbon materials for advanced wearable energy storage systems.

• An ultra-microporous carbon material simultaneously with high specific surface area (1554 m 2 g −1) and packing density (1.18 g cm −3) is designed and fabricated. • The resulting carbon material integrates the high gravimetric and volumetric capacitance (430 F g −1 and 507 F cm −3 at 0.5 A g −1) and thereof provides the robust all-solid-state cellulose supercapacitor with high areal and volumetric density. ABSTRACT A breakthrough in advancing power density and stability of carbon-based supercapacitors is trapped by inefficient pore structures of electrode materials. Herein, an ultramicroporous carbon with ultrahigh integrated capacitance fabricated via one-step carbonization/activation of dense bacterial cellulose (BC) precursor followed by nitrogen/sulfur dual doping is reported. The microporous carbon possesses highly concentrated micropores (~ 2 nm) and a considerable amount of sub-micropores (< 1 nm). The unique porous structure provides high specific surface area (1554 m 2 g −1) and packing density (1.18 g cm −3). The synergistic effects from the particular porous structure and optimal doping effectively enhance ion storage and ion/electron transport. As a result, the remarkable specific capacitances, including ultrahigh gravimetric and volumetric capacitances (430 F g −1 and 507 F cm −3 at 0.5 A g −1), and excellent cycling and rate stability even at a high current density of 10 A g −1 (327 F g −1 and 385 F cm −3) are realized. Via compositing the porous carbon and BC skeleton, a robust all-solid-state cellulose-based supercapacitor presents super high areal energy density (~ 0.77 mWh cm −2), volumetric energy density (~ 17.8 W L −1), and excellent cyclic stability.

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Advancement in developing superelastic carbon aerogels is highly demanded in new industry sectors, particularly in wearable functional electronics for artificial intelligence applications. However, it is very challenging to increase the compressive strength and electrical conductivity while lowering the density of carbon aerogels. Here, an ultralight and superelastic hard carbon aerogel with in situ ultrafine carbon crystals is reported. Based on a novel precursor prepared from self‐assembling bacterial cellulose and thiourea molecules, the resulting aerogel possesses a unique cellular structure and simultaneously exhibits remarkable compressive and electrical properties with ultralow density in addition to excellent compressive cyclability. Specifically, the normalized compression strength and electrical conductivity are up to 20 and 10 times, respectively, of reported carbon aerogels. Armed with the compressed aerogel electrodes, the supercapacitor exhibits excellent electrochemical performance in areal capacitance, rate capability, and high‐power cyclic stability. Furthermore, the supercapacitor displays distinguished pressure‐response capacitive signal and excellent signal cyclicality. This study provides a unique carbon aerogel for advanced wearable monitoring and energy storage systems.