This study demonstrates the first example of a stretchable and wearable textile-based hybrid supercapacitor–biofuel cell (SC–BFC) system. The hybrid device, screen-printed on both sides of the fabric, is designed to scavenge biochemical energy from the wearer's sweat using the BFC module and to store it in the SC module for subsequent use. The BFC relies on lactate, which is oxidized enzymatically to generate electricity. The generated bioenergy is stored directly and rapidly in the printed in-plane SCs. The SC energy-storage module employs MnO₂/carbon nanotube composites that offer high areal capacitance and cycling electrochemical stability. Both printed SC and BFC devices rely on optimal elastomer-containing ink formulations and serpentine structure patterns that impart a stable electrochemical performance after a variety of mechanical deformations. Such a fabrication route ensures that the energy-harvesting and storage properties of the two integrated devices are not compromised. The SC–BFC hybrid system can thus deliver stable output over long charging periods, boost the voltage output of the BFC, and exhibit favorable cycling ability. Such attractive performance, demonstrated in successful on-body testing, along with the unique architecture and low-cost scalable fabrication, make the new garment-ased hybrid energy device useful for meeting the power and mechanical resiliency requirements of wearable electronics and smart textiles.

Based on the great advantages of an inner hollow structure and excellent solid counterpart capacity, complex hierarchical structures have been widely used as electrodes for lithium‐ion batteries. Herein, hierarchical yolk–shell Cu₂O@CuO‐decorated RGO (YSRs) was designed and synthesized via a multi‐step approach. Octahedron‐like Cu₂O‐decorated RGO was firstly produced, in which GO was reduced slightly while cuprous oxide was synthesized. Subsequently, the controlled oxidation of Cu₂O@RGO led to the synthesis of special YSRs, which were composed of a solid Cu₂O core, spur‐CuO, CuO shell, and RGO covered. As anode materials, YSRs could provide considerable capacity density. Meanwhile, the void existed between shells and solid active materials retaining the advantages of inner hollow structure. As a result, the unique architecture of the materials renders the composites with enhanced electronic and ionic diffusion kinetics, high specific capacity (~894 mAh g^‐1, 0.1C), and an excellent rate capability.