Structural energy storage requires batteries with good energy storage as well as mechanical properties. This technology may lead to substantial mass and volume savings in electric automobiles, cube satellites, and aerospace applications by storing energy within the vehicle’s body panels. However, until now, most studies on structural energy storage focus on conventional cathode materials such as lithium iron phosphate (LFP), lithium cobalt oxide (LCO) or nickel manganese cobalt oxide (NMC). Not just potential environmental hazards, but these materials also exhibit poor rate capabilities at higher C-rates and low capacity retention during long-term cycling of batteries. These also suffer with poor adhesion to current collectors that leads to delamination of the electrode layer. Organic radical polymers are a promising alternative because they are environmentally benign, they exhibit rapid charge transfer ability, and good cycling stability. In this work, we report for the first time, structural lithium-ion battery cathodes using organic redox active polymers such as PTMA (poly (2,2,6,6-tetramethyl- piperidenyloxyl-4-yl methacrylate)) as the electrochemically active material. A one-step, polymer-compatible thermal cross-linking method is carried out to significantly inhibit PTMA’s dissolution in the electrolyte. PTMA slurries are casted on mechanically strong reduced graphene oxide (rGO)/branched aramid nanofiber (BANF) films. The rGO/BANFs composites provide structural support and improved adhesion with the active material while also acting as the current collector. The effects of cross-linking agent and active material contents on the electrochemical and mechanical performance are investigated. This work provides a pathway for utilising environmentally benign, redox active radical polymers as active materials in structural lithium-ion batteries.

Structural lithium-ion battery cathodes based on organic redox active polymers and kevlar aramid nanofibers

ACS Spring 2022

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