Highly flexible, thin, and stable battery integrating organohydrogel electrolytes and carbon fabric electrodes for soft electronics

Flexible and mechanically compliant power sources are increasingly required for wearable electronics and soft robotic systems, where stable operation under bending and other deformations must be combined with safety, comfort, and long-term durability. Although hydrogel-based electrolytes are attractive because of their softness, ionic conductivity, and low flammability, practical implementation remains limited by weak gel–gel and gel–electrode interfaces, deformation-sensitive electrical output, and insufficient environmental stability caused by drying, freezing, and swelling. In this study, we propose a thin, highly flexible battery based on an integrated five-layer acrylamide-gel cell composed of a high-salinity gel, an anion-selective gel, a low-salinity gel, a cation-selective gel, and a second high-salinity gel. These layers are monolithically bonded using gel prepolymer solutions to suppress interfacial failure and structural collapse while maintaining ionic conductivity. Flexible carbon fabric electrodes are implemented at both ends, and the entire device is encapsulated with a thin silicone elastomer to maintain mechanical compliance while providing packaging protection. In addition, glycerol is introduced into the gels to form an organohydrogel, thereby improving resistance to dehydration and enhancing environmental robustness for long-term use. The proposed design also enables lateral series integration of cells, allowing system voltage to be increased without increasing device thickness. Experimental evaluations focusing on long-term stability, discharge behavior, and flexibility are performed to examine the feasibility of the proposed device for thin, soft, and wearable power applications.