An all-in-one multifunctional carbon fiber composite material using electrochemistry

In nature, almost all materials perform multiple functions simultaneously, whereas man-made materials are typically optimized for a single function. Multifunctional materials offer a pathway to mimic nature, enabling materials that require fewer resources, reduce system mass and volume, and improve energy efficiency. Although multifunctional materials exist, they rarely combine more than two functions at the same time. Here we demonstrate a carbon fiber (CF) composite material that exhibits five different physical functions simultaneously: structural load carrying, energy storage, strain sensing, shape-morphing, and energy harvesting. This is achieved by utilizing the mechanical properties of CFs, their ability to reversibly intercalate Li-ions in their atomic structure, and the piezo-electrochemical transducer effect observed in lithiated CFs. The composite provides flexible performance, as it can be tailored toward specific functions through the design of its constituent materials and architecture. This concept could lead to significantly more efficient structural materials for a wide range of future applications.