Flexible Batteries: From Mechanics to Devices

With the rapid development of wearable electronics, it is desirable to design and develop flexible power supplies, especially rechargeable lithium ion batteries, with high performance and superior flexibility and durability for integration into electronics. Structures and materials are two key factors in achieving the flexibility of batteries. Therefore, it becomes important to understand the fundamental mechanics in order to better guide us in the design of flexible batteries to meet the requirements of wearable electronics. In this work, we review recent research progress on batteries for wearable electronics based on structures and materials, covering the fundamental mechanics underlying the structural design mechanism and intrinsically deformable materials as building blocks for flexible batteries. In addition, we review and discuss emerging new materials and structures that could potentially revolutionize the design concepts of flexible batteries for wearable electronics. Therefore, these flexible and wearable materials and structures are not limited to batteries. We can envision that the mechanics and design concepts can also be extended to other electronics for wearable applications.