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 (∼6 mg cm–3) enables slurry infiltration of LTO and NCM to form composite electrodes with tunable mass loadings (∼3–30 mg cm–2), and the resultant composites can withstand 100-fold compression (from 3.2 mm to ∼30–130 μm) 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 the rGO-PAA current collector to reduce the weight and volume of lithium-ion electrodes without sacrificing energy density.