How structural batteries work and what they mean for engineering design

Structural batteries represent an innovative approach to energy storage by integrating battery functionality directly into structural components, potentially reducing weight and improving efficiency in electric vehicles (EVs) and other machines. Unlike traditional designs where batteries and structural elements are separate—adding significant mass—structural battery composites combine mechanical strength and electrochemical energy storage in a single material. This concept, first explored in 2007 and advanced notably by researchers at Chalmers University of Technology in Sweden in 2021, uses carbon fiber as the negative electrode and lithium iron phosphate-coated carbon fiber as the positive electrode. The assembly includes a separator layer and is infused with a polymer precursor and liquid electrolyte, which solidifies into a rigid composite that supports mechanical loads while enabling lithium-ion conduction. The manufacturing process involves vacuum infusion and heat curing, resulting in a dual-phase material: a solid polymer matrix for strength and a liquid electrolyte trapped in nanoscale pores for ion transport. This design achieves a balance between structural integrity and battery performance. In 2024