Structural batteries combine the energy storage properties of batteries with the mechanical properties of structural composites. Such devices can lead to significant mass and volume savings in aerospace and ground transportation as energy may be stored within structural body panels. The major challenge is that conventional battery electrodes suffer from poor mechanical properties (tensile strength &lt; 4 MPa and Young’s modulus &lt; 1 GPa) hindering their use in structural applications. Here, we address this by utilizing, for the first time, Kevlar® aramid nanofibers as binders for lithium-ion battery cathodes and anodes. We report on the development of free-standing electrodes consisting of branched aramid nanofibers (BANFs), reduced graphene oxide (rGO), and lithium iron phosphate (LFP) for the cathodes or silicon (Si) for the anodes. BANFs possess excellent mechanical properties, such as tensile strength and Young’s modulus. rGO sheets exhibit high electrical conductivity, while LFP and Si act as the battery active materials. The effect of BANF addition on mechanical and electrochemical properties was investigated. BANFs led to structural electrodes with up to two orders of magnitude improvements in tensile strength and Young’s modulus compared to commercial battery electrodes while maintaining similar energy storage performance. To further elucidate on the role of BANFs, an in-depth characterization of the electrodes’ morphology, impedance, and SEI formation was conducted. This work demonstrates an efficient way for developing mechanically strong lithium-ion battery electrodes.

Structural lithium-ion battery electrodes reinforced with Kevlar aramid nanofibers

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.