Unveiling the Multifunctional Carbon Fiber Structural Battery

Structural batteries refer to the multifunctional device capable of both storing electrical energy and bearing mechanical loads concurrently. In this context, carbon fibers emerge as a compelling choice of material and serve dual purpose by storing energy and providing stiffness and strength to the battery. Previous investigation has demonstrated proof-of-concept of functional positive electrodes against metallic lithium in structural battery electrolyte. Here, an all-carbon fiber-based structural battery is demonstrated utilizing the pristine carbon fiber as negative electrode, lithium iron phosphate (LFP)-coated carbon fiber as positive electrode, and a thin cellulose separator. All components are embedded in structural battery electrolyte and cured to provide rigidity to the battery. The energy density of structural battery is enhanced by use of the thin separator. The structural battery composite demonstrates an energy density of 30 Wh kg-1 and cyclic stability up to 1000 cycles with approximate to 100% of Coulombic efficiency. Remarkably, the elastic modulus of the all-fiber structural battery exceeds 76 GPa when tested in parallel to the fiber direction - by far highest till date reported in the literature. Structural batteries have immediate implication in replacing structural parts of electric vehicles while reducing the number of conventional batteries. Thus, offering mass savings to future electric vehicles. Multifunctional structural batteries are set to revolutionize transportation by enhancing vehicle driving range and reducing energy consumption. This study demonstrates a fully functional structural battery, achieving the highest multifunctional performance to date. A cost-effective approach ensures multifunctionality from electrode fabrication to maintaining the mechanical properties of LFP-deposited carbon fibers, enhanced rigidity through biphasic solid-liquid electrolyte, and subsequent battery stiffness. image