Aqueous zinc ion capacitors(ZICs)composed of porous carbon cathode and Zn metal anode have attracted great research interest in recent years due to their advantages of low cost,environmental friendliness,high safety,and long-term durability.This work first synthesized a N-containing polymer as the precursor by condensation of melamine chloride and p-phenylenediamine,and then fabricated N-enriched porous carbon nanosheets(NPCN-x)with a high N content(>10%)by a carbonization and self-activation strategy.The influence of carbonization temperature on the morphology,microstructure,surface chemical properties,and electrochemical performance of NPCN-x was investigated in detail.The results showed that carbonization temperature had a significant regulation effect on the N-doped configurations.It was revealed that the pyrrolic N configuration within NPCN-x materials played a crucial role in improving their electrochemical performance.As a consequence,the optimized NPCN-800 sample with the highest pyrrolic N content of 2.15%delivered a high specific capacity up to 158mAh/g at 0.5A/g and excellent cycling performance as the cathode for ZICs.To further explore the storage mechanism of Zn ions on the N-doped carbon surface during the electrochemical process,density functional theory(DFT)calculations were performed,which showed that the pyrrolic N configuration possessed the strongest adsorption capability for Zn ions,suggesting superior electrochemical activity in comparison to other N-doped configurations.This work provided a new insight from both theoretical and experimental perspectives for constructing porous carbon materials for high-performance ZICs.
关键词
多孔碳纳米片/氮掺杂调控/锌离子存储/电化学/优化设计
Key words
porous carbon nanosheets/N-doped configurations/zinc ion storage/electrochemistry/optimal design
维普
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