Scalable Multilayer Printing of Graphene Interfacial Layers for Ultrahigh Power Lithium‐Ion Storage

Abstract

A low resistance graphene‐based interfacial layer is developed for multilayered lithium‐ion capacitor electrodes using a layer‐by‐layer printing approach, with the goal of boosting energy storage performance at ultrafast charge/discharge rates (≥100 C). The electrochemical behavior of spray printed Li4Ti5O12‐based heterostructure electrodes is investigated as a thin, discrete graphene layer is placed: 1) at the base of the Li4Ti5O12 (at the electrode/current collector interface); 2) on the top of the Li4Ti5O12 (at the electrode/separator junction); and 3) both at the base and on the top of the Li4Ti5O12 (sandwich configuration), with marked improved electrode performance at >50 C when the graphene layer is interleaved at the Li4Ti5O12/current collector interface. This best performing heterostructure negative electrode is then coupled with a spray printed activated carbon positive electrode in a lithium‐ion capacitor configuration, showing an attractive power density of ≈8000 W kg−1 at 350 C. The fabrication of double‐sided graphene/Li4Ti5O12 multilayered heteroelectrodes is successfully demonstrated over areas of 20 cm × 15 cm and in various patterned configurations.