▎ 摘　　要

Lignin extracted from trees is one of the most abundant biopolymers on Earth. Quinone, a substructure in lignin, can be used for energy storage via reversible redox reactions through absorbing and releasing electrons and protons. However, these efforts have encountered hindrances, such as short life cycle, low cycling efficiency, and a high self discharge rate. All of these issues are related to electrode dissolution by electrolyte solvents and the insulating nature of lignin. Addressing these critical challenges, for the first time, we use a reconfigurable and hierarchical graphene cage to capture the lignin by mimicking the prey-trapping of venus flytraps. The reconfigurable graphene confines the lignin within the electrode to prevent dissolution, while acting as a three-dimensional current collector to provide efficient electron transport pathways during the electrochemical reaction. This bioinspired design enables the best cycling performance of lignin reported so far at 88% capacitance retention for 15 000 cycles and 211 F/g capacitance at a current density of 1.0 A/g. This study demonstrates a feasible and effective strategy for solving the long-term cycling difficulties of lignin-based electrochemically active species and makes it possible to utilize lignin as an efficient, cheap, and renewable energy storage material.