Facile Preparation of an Excellent Mechanical Property Electroactive Biopolymer-Based Conductive Composite Film and Self-Enhancing Cellulose Hydrogel to Construct a High-Performance Wearable Supercapacitor

摘要

Wearable supercapacitors, as one of the most important power supplies for wearable electronics, require excellent flexibility and deformability and a structure that is not easily delaminated. In this work, a robust ligninsulfonate/single-wall carbon nanotube film/holey reduced graphene oxide (Lig/SWCNT/HrGO) film with excellent tensile strength (121.8 MPa) and flexibility has been prepared via a filtration process followed by a hydrothermal treatment. During the filtration process, the SWCNT and small-size holey graphene oxide (HGO) can form a multilayer-like interconnected structure, and a part of HGO with a large specific surface area intersperses in the SWCNT network. HGO can be further reduced to HrGO, and the HrGO, Lig, and SWCNT can combine tightly to generate a compact multilayer-like structure during the hydrothermal process. High-strength, flexible, porous cellulose hydrogel (9.56 MPa) has been fabricated via a self-enhancing method through phase inversion of microcrystalline cellulose and partially dissolved bacterial cellulose mixture dispersion. A wearable supercapacitor is assembled by the Lig/SWCNT/HrGO films and self-enhancing cellulose hydrogel, which exhibits excellent tensile strength (112.3 MPa), areal capacitance (1121 mF cm(-2)), and energy density (77.8 mu Wh cm(-2)). More importantly, the areal capacitance shows a nearly linear increase with an increase in the mass of the film electrode. When the film electrode mass reaches up to 16.5 mg cm(-2), the wearable supercapacitor delivers an ultrahigh areal capacitance of 4110 mF cm(-2) and an energy density of 285.4 mu Wh cm(-2). Remarkably, the wearable supercapacitor can sustain many types of arbitrary deformation and this outstanding flexibility is attributed to the strong interaction between wood-derived cellulose and Lig, which prevents the delamination of the electrodes and the separator. This work provides a facile approach for the preparation of a biopolymer-based, multilayer-like structure film and a self-enhancing method to obtain high-strength cellulose hydrogel, thus developing a biomimetic high-performance wearable energy storage device.