Rendering wood veneers flexible and electrically conductive through delignification and electroless Ni plating

Abstract

Wood has unique advantages. However, the rigid structure and intrinsic insulating nature of wood limit its applications. Herein, a two-step process is developed to render wood veneers conductive and flexible. In the first step, most of the lignin and hemicellulose in the wood veneer are removed by hydrothermal treatment. In the second step, electroless Ni plating and subsequent pressing are carried out. The obtained Ni-plated veneer is flexible and bendable, and has a high tensile strength of 21.9 and 4.4 MPa along and across the channel direction, respectively, the former of which is considerably higher than that of carbon cloth and graphene foam. Moreover, this product exhibits high electrical conductivity around 1.1 × 103 S m-1, which is comparable to that of carbon cloth and graphene foam, and significantly outperforms previously reported wood-based conductors. This work reveals an effective strategy to transform cheap and renewable wood into a high value-added product that rivals expensive carbon cloth and graphene foam. The obtained product is particularly promising as a current collector for flexible and wearable electrochemical energy storage devices such as supercapacitors and Li-ion batteries.