三维氮掺杂分级多孔碳纳米片的制备及储锌性能
Preparation and Zinc Storage Properties of Three-dimensional Nitrogen-doped Hierarchical Porous Carbon Nanosheets
何军 1朱傲阳 1魏雨晨 1朱怡全 1蒋莉 2何孝军1
作者信息
- 1. 安徽工业大学化学与化工学院,煤清洁转化与高值化利用安徽省重点实验室,马鞍山 243002
- 2. 安徽工业大学继续教育学院,马鞍山 243002
- 折叠
摘要
以MgO@ZIF-8为双模板和辅助碳源,KHCO3为活化剂,煤沥青(CTP)为碳源,制备了三维氮掺杂分级多孔碳纳米片(N-CNs),探究了KHCO3与CTP的质量比对N-CNs的结构、化学组成和锌离子储存性能的影响.结果表明,当KHCO3与CTP的质量比为3∶1时,制备的样品(N-CN3)具有三维互连的碳纳米片结构、高比表面积(2360 m2/g)和吡咯氮含量.将N-CN3作为锌离子混合电容器(ZHCs)正极时,其在2 mol/L ZnSO4电解液中展现了出色的比容量(当电流密度为0.2 A/g时,比容量为157.6 mA·h/g)、高的能量密度(在176.1 W/kg功率密度下能量密度为126.5 W·h/kg)和优异的循环稳定性(当电流密度为5 A/g时,经过20000次循环后容量仅衰减6.4%,库仑效率为99.6%).密度泛函理论计算结果证实,吡咯氮掺杂增加了电极材料对锌离子的吸附能,提高了N-CNs对锌离子的吸附容量.
Abstract
In this work,three-dimensional nitrogen-doped hierarchical porous carbon nanosheets(N-CNs)were synthesized from coal tar pitch(CTP)by using MgO@ZIF-8 as double template and auxiliary carbon source coupled with KHCO3 in situ activation.The effects of the mass ratio of KHCO3 to CTP on the structure,chemical composition and zinc ion storage properties of N-CNs were investigated.The as-prepared N-CN3 at a mass ratio of 3∶1 of KHCO3 to CTP features a three-dimensional interconnected carbon nanosheet structure,high specific surface area(2360 m2/g)and pyrrole nitrogen content.Benefiting from the above characteristics,the N-CN3 cathode of zinc-ion hybrid capacitor(ZHCs)in 2 mol/L ZnSO4 exhibits excellent specific capacity(157.6 mA·h/g at 0.2 A/g),high energy density(126.5 W·h/kg at 176.1 W/kg)and exceptional cycle stability(only 6.4%capacity decay after 20000 cycles at 5 A/g and 100%Coulomb efficiency).The density functional theory(DFT)calculation results verified the enhance-ment of the adsorption energy to Zn2+due to the presence of pyrrole nitrogen in N-CNs,thus leading to enhanced adsorption capacity of N-CNs to zinc ions.This work prides an efficient method for the high-added value utilization of coal chemical by-products.
关键词
锌离子混合电容器/煤沥青/多孔碳/MgO@ZIF-8/密度泛函理论计算Key words
Zinc-ion hybrid capacitors(ZHCs)/Coal tar pitch(CTP)/Porous carbon/MgO@ZIF-8/Density functional theory calculation引用本文复制引用
基金项目
国家自然科学基金(52372037)
国家自然科学基金(52072002)
安徽省高等学校优秀科研创新团队项目(2023AH010015)
出版年
2024
国家科技期刊平台
NSTL
万方数据