Higher strength carbon fiber lithium-ion polymer battery embedded multifunctional composites for structural applications

Abstract

This study proposes and evaluates the structural integrity of a carbon fiber reinforced polymer (CFRP) composite containing encapsulated lithium-ion polymer (Li-Po) batteries. A comparison of various composite structures made of CFRP having the core of lithium-ion batteries is conducted. Electrospinning is globally recognized as a flexible and cost-effective method for generating continuous nanofilaments. In this study, epoxy-multiwalled carbon nanotubes (CNT/epoxy) were electrospun onto CFRP layers, which improved interfacial bonding and strong adhesion between the layers which ultimately worked as an effective packaging for Li-ion batteries. This composite structure showed enhanced mechanical strength compared to the standard CFRP laminate structure due to incorporating electrospun CNT/epoxy nanofibers in between the layers. An alternate method was proposed for comparison where CNT/epoxy was air sprayed onto the CFRP layers. CFRP structure containing airsprayed CNT/epoxy was found to be stronger than standard CFRP laminate structure, although not as strong as electrospun CNT/epoxy enhanced CFRP laminates. Finally, the design validation, manufacturing method, and electromechanical characterization of multifunctional energy storage composites (MESCs) were examined and compared. Electrochemical characterization showed that MESCs with electrospun CNT/epoxy nanofibers enhanced CFRP laminate under loading conditions had similar performance to the standard lithium-ion pouch cells without any loading. The mechanical robustness of the proposed CFRP composite structures enables their manufacturing as multifunctional energy-storage devices for electric vehicles and other structural applications.