Ye Cong

The development of high-performance carbon anodes from coal liquefaction pitch for sodium-ion batteries (SIBs) remains challenging due to insufficient functional groups, uncontrollable graphitization, and the lack of precise molecular-level regulation, which collectively lead to inadequate Na+ storage sites, restricted interlayer spacing, and sluggish ion transport kinetics. To address these limitations, we propose a molecular structure-oriented strategy that integrates solvent fractionation, pre-oxidation, and structure-matched cross-linking to precisely tailor the architecture of pitch-derived carbons. The toluene-soluble (TS) fraction of pitch, which is rich in small aromatic cores and abundant aliphatic side chains, is selectively pre-oxidized to introduce carbonyl groups. These groups subsequently undergo esterification with hydroxyl-rich chitin, constructing a three-dimensional cross-linked network via -C(O)-O- linkages. This molecularly designed network imposes spatial confinement, effectively inhibiting graphitic layer rearrangement during pyrolysis and resulting in pseudo-graphitic carbons with expanded interlayer spacing and abundant closed ultramicropores. As an anode for SIBs, the resulting carbon (OTSCC) delivers a high reversible capacity of 318 mAh g-1, an initial Coulombic efficiency of 76.1%, and remarkable cycling stability with 82.5% capacity retention after 500 cycles at a current density of 500 mA g-1. This work underscores the critical role of precursor fraction control and molecular-matched cross-linking in designing advanced carbon materials for energy storage, providing a rational synthesis pathway towards high-performance SIB anodes.

With the rapid advancement of renewable energy technologies and growing demand for high-efficient energy storage, supercapacitors have attracted great attention in academia and industry. Porous carbon materials with tailored hierarchical structures are regarded as the most promising electrode candidates for boosting their electrochemical performance. To address the environmental and cost challenges caused by highly corrosive potassium hydroxide (KOH) as an activator, this study proposes an environmentally benign strategy for synthesizing three-dimensional (3D) hierarchical porous carbon materials using pitch as a low-cost carbon precursor. Specifically polyurethane foam is explored as a sustainable macroporous scaffold template, and potassium carbonate (K2CO3) is adopted as a mild and eco-friendly activating agent to synergistically construct micropores and mesopores during the activation process, thereby achieving a well-developed hierarchical pore structure in the carbon matrix. The results demonstrate that the optimized APCs-800, prepared at an activation temperature of 800 ℃ with a pitch/polyurethane/K2CO3 mass ratio of 2:1:6, delivers an enhanced specific capacitance of 137.5 F g-1 at 0.5 A g-1, a high-rate capability of 115.0 F g-1 at 10 A g-1, and competitive cycling stability with 97.8% capacitance retention after 20,000 cycles. This work provides a feasible pathway for the fabrication of hierarchical porous carbon electrodes with tailored structures, offering valuable insights for the advancement of sustainable supercapacitor technologies.

While pre-oxidation effectively introduces oxygen-containing functional groups in pitch to suppress graphitization during carbonization, it remains constrained by slow oxygen diffusion kinetics, often leading to inhomogeneous oxidation and limited structural controllability. Herein, we propose a reinforced pre-oxidation strategy for ethylene tar pitch (ETP) by directly incorporating radical initiators (2,3-dimethyl-2,3-diphenylbutane (DMDPB) and benzophenone (BP)). These initiators undergo in situ decomposition to produce abundant free radicals, which substantially elevate the local radical concentration. This approach overcomes the kinetic limitation of conventional oxygen-dependent oxidation, enabling synchronous oxidation across the pitch matrix while improving oxidation efficiency and homogeneity. Consequently, the graphitization tendency of ETP during carbonization is effectively suppressed, leading to enhanced reversible capacity and rate performance. Notably, ETP-derived carbon prepared with 5 wt% BP delivers a high reversible capacity of 310.3 mAh g-1 at 0.02 A g-1 and 116.6 mAh g-1 at 5 A g-1. This work provides a promising route to fabricate high-performance pitch-based hard carbon anodes and fundamental insights into radical-mediated pre-oxidation mechanisms, contributing to the development of low-cost anodes for commercial sodium-ion batteries.