Stretchable, breathable, wearable batteries using a holey design

The rigid and non-breathable nature of conventional batteries has remained a significant limitation on wearable electronics, particularly in applications involving dynamic physical activities. Herein, we present a "holey" battery design, which is both breathable and deformable while maintaining high energy density and ease of fabrication. Guided by the finite element method (FEM), this design incorporates a strategic array of holes within a standard pouch cell framework that significantly enhances the battery's breathability (twice as much as conventional cotton) and stretchability-maintaining robust electrochemical performance under 10% stretching deformation. Importantly, this architecture allows for a high areal energy density, achieving 7.2 mW h/cm(2) in a single-layer pouch, which is scalable to 14.4 mW h/cm(2) using double electrode layers. The battery is resilient under physical stress, including 10% diagonal stretching (>90% capacity) and 180 degrees folding (>95% capacity), with quick recovery upon release, marking a significant advance in the field of e-textiles.