TY - JOUR AU - He, Hongcheng AU - Lian, Jichun AU - Chen, Changmiao AU - Xiong, Qiaotian AU - Li, Cheng Chao AU - Zhang, Ming PY - 2022/04/15 Y2 - 2024/03/29 TI - Enabling Multi-Chemisorption Sites on Carbon Nanofibers Cathodes by an In-situ Exfoliation Strategy for High-Performance Zn–Ion Hybrid Capacitors JF - Nano-Micro Letters JA - Nano-Micro Lett VL - 14 IS - SE - Articles DO - 10.1007/s40820-022-00839-z UR - https://nmlett.org/index.php/nml/article/view/1094 SP - 106 AB - <p>Carbon nanofibers films are typical flexible electrode in the field of energy storage, but their application in Zinc-ion hybrid capacitors (ZIHCs) is limited by the low energy density due to the lack of active adsorption sites. In this work, an in-situ exfoliation strategy is reported to modulate the chemisorption sites of carbon nanofibers by high pyridine/pyrrole nitrogen doping and carbonyl functionalization. The experimental results and theoretical calculations indicate that the highly electronegative pyridine/pyrrole nitrogen dopants can not only greatly reduce the binding energy between carbonyl group and Zn<sup>2+</sup> by inducing charge delocalization of the carbonyl group, but also promote the adsorption of Zn<sup>2+</sup> by bonding with the carbonyl group to form N–Zn–O bond. Benefit from the multiple highly active chemisorption sites generated by the synergy between carbonyl groups and pyridine/pyrrole nitrogen atoms, the resulting carbon nanofibers film cathode displays a high energy density, an ultralong-term lifespan, and excellent capacity reservation under commercial mass loading (14.45&nbsp;mg&nbsp;cm<sup>‒2</sup>). Particularly, the cathodes can also operate stably in flexible or quasi-solid devices, indicating its application potential in flexible electronic products. This work established a universal method to solve the bottleneck problem of insufficient active adsorption sites of carbon-based ZIHCs.Imoproved should be changed into Improved.</p><p>Highlights:</p><p>1 The high pyridine/pyrrole nitrogen-doped and carbonyl-functionalized nanosheets on flexible electrospun porous carbon nanofibers film cathode integrates the advantages of large specific surface area, strong hydrophilicity and high Zn<sup>2</sup>+ adsorption activity.<br>2 The Zinc-ion hybrid capacitors exhibits a high capacitance retention of 99.2% over 200,000 cycles at 40 A g<sup>−1</sup>.<br>3 A synergistic Zn<sup>2+</sup> storage mechanism between carbonyl and pyridine/pyrrole nitrogen atoms is proposed.</p> ER -