Applications of Soft Dendritic Colloids in Li-Ion Batteries with Advanced Structure-Derived Performance

Abstract

Adoption of electric vehicles and increasing demands of consumer electronics require electrochemical energy storage devices with high capacity and rate capabilities. Supply-chain and material-cost concerns as well as charge-rate limitations associated with irreversible lattice changes motivates the replacement of mixed-metal oxide cathodes in lithium-ion batteries (LIBs). Electrochemically active polymeric materials have emerged as promising candidates to replace metal oxides due to their high tunability and increased capacity. However, many of these materials suffer from poor intrinsic electronic conductivity and may be soluble into the electrolyte, causing irreversible capacity fade. Nanostructuring and composite formation are two polymer processing methods that can be leveraged to combat these drawbacks. The introduction of new nanostructured and nanocomposite cell components can decrease diffusion length scales, increase mechanical stability, and allow for higher electronic conductivity in polymer electrodes. Herein, we utilize a new class of polymeric materials called soft dendritic colloids (SDCs) as a platform for creating such nanocomposites. These fibrillar polymeric particles, formed via turbulent solvent-nonsovent induced phase separation, have hierarchical morphology, large aspect ratios and demonstrate pronounced adhesion and network-forming behavior. SDC-based materials have shown impressive results as nonwoven polyvinylidene difluoride separators in Li-ion batteries. Herein, we propose and present their use as Li-ion battery electrodes with advanced structural properties, derived from electroactive polymeric materials.