Intrinsically stretchable fuel cell based on enokitake-like standing gold nanowires

Conventional fuel cells are based on rigid electrodes, limiting their applications in wearable and implantable electronics. Here, it is demonstrated that enokitake-like vertically-aligned standing gold nanowires (v-AuNWs) can also serve as powerful platform for stretchable fuel cells by using ethanol as model system. Unlike traditional fuel cell electrodes, the v-AuNWs have “Janus Morphology” on both sides of the film and also are highly stretchable. The comparative studies demonstrate that tail side exposed v-AuNWs based stretchable electrodes outperform the head-side exposed v-AuNWs toward the electro-oxidation of ethanol due to the direct exposure of high-surface-area nanowires to the fuels. Therefore, a stretchable fuel cell is fabricated utilizing tail side based interdigitated electrodes, where v-AuNWs and Pt black modified v-AuNWs serve as the anode and cathode, respectively. The as-prepared stretchable fuel cell exhibits good overall performance, including high power density, current density, open-circuit voltage, stretchability, and durability. Most importantly, a wearable fuel cell is also achieved by integrating tattoo-like interdigitated electrodes with a thin layer of sponge as a fuel container, exhibiting good performance under various deformations (compression, stretching, and twisting). Such attractive performance in conjunction with skin-like in-plane design indicates its great potential to power the next-generation of wearable and implantable devices.