Structure Modulation of Defective Hierarchical Carbon Materials for Ultrahigh-Rate and Stable Energy Storage

Carbon electrodes with abundant accessible pores and highly connected electronic highways are highly desired. However, the thermodynamically uncontrollable reaction interface and severe topology self-aggregation happen under the manufacturing process, which hinders the practical implementation of carbon materials. Here, a defective hierarchical carbon electrode is tailored through a straightforward inspissate gum calcination strategy, which contains highly connected nanotube subunits with rich defects (I_D/I_G>2.4) and functional groups. Theory simulation indicates the defect/heteroatoms on the curved carbon matrix increase the density of states near the Fermi level, which not only facilitates the electronic transfer but also enables the intimate adsorption of electrolyte ions, responsible for the efficient energy storage under large-current conditions. As such, the defective hierarchical carbon achieves a record-level rate property of 14k mV s⁻¹ for electrochemical energy storage, besides, a sound capacitance of 6.2 F cm⁻² is delivered at a high mass loading of 37 mg cm⁻², superior to many state-of-the-art carbon materials. Moreover, the dynamic non-covalent interaction enables pre-machining of the carbon electrode, which is responsible for the formation of all-in-one binder-free symmetric supercapacitors with satisfactory performances. This work presents guidance and a fundamental understanding of the solid-solid interface reconstruction to promote the discovery of carbon microstructure.