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 LiFePO4 as 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-1 at 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.