(Invited) Heteronanomat Frameworks As a New Electrode Design for Advanced Lithium-Ion Batteries

Abstract

Forthcoming smart energy era is in strong pursuit of advanced power sources with reliable electrochemical performances. To date, most research approaches have still relied on traditional synthetic materials and stereotyped electrode architecture (i.e., thickness-directional, simple pile-up of electrode active materials/conductive additives/polymeric binders on top of metallic current collectors), which have posed major obstacles to sustainable progress of the energy storage systems. For example, the presence of electrochemically-inert materials such as metallic current collectors and polymer binders exerts negative influence on volumetric/gravimetric capacity of electrodes. Moreover, the monotonous electrode architecture often gives rise to electrode thickness-dependent irregularity of electronic/ionic conduction pathways and also loss of structural integrity upon external deformation stresses. Here, we demonstrate a new class of heteronanomat-structured electrodes based on carbon nanotubes (CNTs), cellulose nanofibrils and electrospun polymeric nanofibers to resolve the long-standing challenges of conventional electrodes described above. This material/structural uniqueness allows the formation of three-dimensional bicontinuous CNT electron networks and electrolyte conduction channels, in addition to improving the mass loading of electrode active materials and also mechanical flexibility. As a result, the heteronanomat electrodes provide unprecedented advances in the electrochemical performance and shape diversity that lie far beyond those achievable with conventional battery electrode architectures. We envision that the heteronanomat-structured electrode strategy holds a great deal of promise as a reliable and versatile platform technology to open a new route toward advanced lithium-ion batteries. References Sang-Young Lee et al. Adv. Energy Mater. 2017, 1701099.Sang-Young Lee et al. Adv. Funct. Mater. 2015, 25, 6029.Sang-Young Lee et al. Adv. Energy Mater. 2015, 5, 1501194. Figure 1