Carbon Nanotubes Coated Paper as Current Collectors for Secondary Li-ion Batteries

Abstract We developed a surfactant-free spray coating process to coat commercial cellulose-based paper with carbon nanotubes (CNTs) and prepared paper-CNTs current collectors for Li-ion batteries (LIBs). The paper-CNTs were used as current collectors for replacing conventional aluminum foil. Li-ion batteries assembled using paper-CNTs were coated with LiFePO₄as the active material and used as cathodes with Li as the anode, and the assembled LIBs showed a high energy density of 460 Wh kg⁻¹at a power density of 250 W kg⁻¹. These electrodes were stable even at a current density as high as 600 mA g⁻¹, and showed cycling stability for ~450 cycles at 150 mAh g⁻¹. Furthermore, paper-CNTs based electrodes showed ~17% improvement in areal capacity compared to commercial aluminum-based electrodes suggesting that paper-CNTs can readily displace Al foils as current collectors. Summary: Paper based current collectors have been proposed as a cost-effective and simple replacement for aluminum current collectors. This has been achieved by a scalable spray coating of CNTs on printing papers without any surfactants or binders and subsequently testing them as current collectors for Li-ion batteries.