Compact Lithium-Ion Battery Electrodes with Lightweight Reduced Graphene Oxide/Poly(Acrylic Acid) Current Collectors

We report the fabrication and electrochemical performance of metal-foil free Li4Ti5O12 (LTO) and LiNi1/3Co1/3Mn1/3O2 (NCM) electrodes supported on conductive and porous reduced graphene oxide/poly(acrylic acid) (rGO-PAA) aerogels. The highly porous rGO-PAA (similar to 6 mg cm(-3)) enables slurry infiltration of LTO and NCM to form composite electrodes with tunable mass loadings (similar to 3-30 mg cm(-2)), and the resultant composites can withstand 100-fold compression (from 3.2 mm to similar to 30-130 yin) to achieve electrode densities of 2-3 g cm(-3). The adequate compressibility of the rGO-PAA coupled with removal of the conventional metal-foil weight and volume provides high volumetric energy densities of 1723 Wh L-1 for NCM and 625 Wh L-1 for LTO at low power density, representing a 25% increase in energy density over similar electrodes built with metal-foil current collectors. These metrics demonstrate the utility of rGO-PAA current collector to the reduce the weight and volume of lithium-ion electrodes without sacrificing energy density.