Mimosa plant leaf-inspired 180° foldable lithium-ion batteries with enhanced electrochemical-mechanical behaviors

Abstract

Developing high-performance batteries with flexibility is crucial for flexible electronic applications. Although various types of flexible battery designs have been proposed in recent years to improve cycling performance and flexibilities, their application is limited in the most widely used flexible device, namely foldable screen smartphones, due to their inability of 180° folding. Here, inspired by the unique dynamic property of the mimosa plant leaf, we design a bio-inspired flexible lithium-ion battery (FLIB) containing thick energy-storage modules, analogous to the leaflets, and electrical contact part, analogous to the leaf stalk. This design resulted in a FLIB with high flexibility (180° folding and bending), cycling stability, and scalability. Notably, our FLIB demonstrated an improved cycling performance, even under harsh dynamic deformations (10,000-times dynamic 180° folding and 7500-times dynamic bending). The potential mechanisms of mechanical protection for the FLIB were investigated through finite element analysis, further proving its remarkable mechanical endurance. Therefore, our flexible battery design meets the demand of flexible devices for stable power supply under various deformation states. This work sheds new light on the structural innovations and practicality of flexible batteries for future applications.