Multi-stage explosion of lignin: a new horizon for constructing defect-rich carbon towards advanced lithium ion storage

Abstract

The sluggish solid-state diffusion kinetics is the key challenge for turbostratic carbon in lithium-based energy storage. Interconnected mesoporosity and multi-scale structures are effective ways of optimizing the kinetics. Herein, a novel strategy of multi-stage explosion through calcium oxalate (CaC₂O₄) thermal decomposition was designed to prepare a defect-rich popcorn-like lignin-derived mesoporous carbon cage (PLPCC). The PLPCC prepared by two-stage explosion (PLPCC-700) displays an interconnected mesoporous structure and two-dimensional nanosheets/three-dimensional mesoporous carbon network with abundant active carbonyl and edge nitrogen defects. PLPCC-700 delivers excellent reversible capacity (706.3 mA h g⁻¹ at 0.2 A g⁻¹) and superior rate capability (530.4 mA h g⁻¹ at 1 A g⁻¹). The assembled Li-ion capacitor device delivers a considerable energy density of 79.2 W h kg⁻¹. In this work, a green and delicate strategy is designed to prepare defect-rich carbon from industrial lignin residues for advanced energy storage.