High-Energy-Density Foldable Battery Enabled by Zigzag-Like Design

Flexible batteries, seamlessly compatible with flexible and wearable electronics, attract a great deal of research attention. Current designs of flexible batteries struggle to meet one of the most extreme yet common deformation scenarios in practice, folding, while retaining high energy density. Inspired by origami folding, a novel strategy to fabricate zigzag-like lithium ion batteries with superior foldability is proposed. The battery structure could approach zero-gap between two adjacent energy storage segments, achieving an energy density that is 96.4% of that in a conventional stacking cell. A foldable battery thus fabricated demonstrates an energy density of 275 Wh L⁻¹ and is resilient to fatigue over 45 000 dynamic cycles with a folding angle of 130°, while retaining stable electrochemical performance. Additionally, the power stability and resilience to nail shorting of the foldable battery are also examined.