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

Abstract

We\nreport the fabrication and electrochemical performance of metal-foil\nfree Li₄Ti₅O₁₂ (LTO) and LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) electrodes\nsupported on conductive and porous reduced graphene oxide/poly­(acrylic\nacid) (rGO-PAA) aerogels. The highly porous rGO-PAA (∼6 mg\ncm^–3) enables slurry infiltration of LTO and NCM\nto form composite electrodes with tunable mass loadings (∼3–30\nmg cm^–2), and the resultant composites can withstand\n100-fold compression (from 3.2 mm to ∼30–130 μm)\nto achieve electrode densities of 2–3 g cm^–3. The adequate compressibility of the rGO-PAA coupled with removal\nof the conventional metal-foil weight and volume provides high volumetric\nenergy densities of 1723 Wh L^–1 for NCM and 625\nWh L^–1 for LTO at low power density, representing\na 25% increase in energy density over similar electrodes built with\nmetal-foil current collectors. These metrics demonstrate the utility\nof the rGO-PAA current collector to reduce the weight and volume of\nlithium-ion electrodes without sacrificing energy density.