摘要
多碘化合物的溶解所导致的穿梭效应是制约锌-碘电池(Zn-I_(2))性能的关键问题。作为Zn-I_(2)电池重要的电极材料之一,多孔碳材料的孔结构和表面化学组成会显著影响Zn-I_(2)电池的性能。采用机械球磨的方法,以纳米氧化锌为模板和金属离子源实现了百克级ZIF-8@ZnO的制备,借助纳米ZnO的物理限域作用和ZIF-8中丰富的微孔及高氮含量,高温热解后获得了大量介孔和微孔共存的N掺杂多孔碳(记为NC-x,x为热解温度)。将NC-x应用于电解质Zn-I_(2)电池,详细研究了其孔结构、N掺杂种类和原子数量百分比等对Zn-I_(2)电池性能的影响:介孔可以缩短电解质的扩散路径,并有效存储所产生的多碘化物,而微孔可以高效吸附I-并抑制I的生成;石墨氮能够显著提高导电性,吡啶氮和吡咯氮作为化学吸附点,增强了碘物种与碳材料之间的作用力,有效抑制穿梭效应。得益于最优的孔结构、掺杂N类型和含量,NC-1000表现出最佳的电化学性能:高容量(1 A/g时为248.6 mAh/g)、出色的倍率性能(在20 A/g时保持86.1 mAh/g),和优异的循环稳定性(10 A/g下16 000次循环后具有90%容量保持率)。综上所述,通过合理的孔径设计和表面组成调控,可以显著提高多孔碳基Zn-I_(2)电池的性能。
The shuttle effect induced by the dissolution of polyiodides constitutes a critical challenge constraining the performance of zinciodine batteries(Zn-I_(2)).As one of the vital electrode materials for Zn-I_(2) batteries,the pore structure and surface chemical composition of porous carbon materials significantly influence the performance of Zn-I_(2) batteries.In this study,a hundred-gram-scale ZIF-8@ZnO composite was synthesized via mechanical ball-milling using nano-ZnO as both a structural template and metal ion source.Serving as carbon precursors,these composites were subjected to high-temperature pyrolysis,leveraging the physical confinement effect of nano-ZnO and the inherent microporosity/nitrogen-rich characteristics of ZIF-8,to obtain nitrogen-doped porous carbons(denoted as NC-x,where x represents the pyrolysis temperature)featuring co-existing mesopores and micropores.The NC-x materials were applied as cathodes in aqueous Zn-I_(2) batteries,and systematic investigations were conducted to elucidate the influence of pore architecture and nitrogen doping configurations on battery performance.Specifically,mesopores shortened the diffusion pathways of the KI electrolyte and effectively confined polyiodide intermediates,while micropores facilitated strong adsorption of I-ions and suppressed I3-formation.Graphitic nitrogen within the carbon framework significantly enhanced electrical conductivity,whereas pyridinic and pyrrolic nitrogen species acted as chemisorption sites to strengthen interactions between iodine species and the carbon matrix,thereby effectively mitigating the shuttle effect.Benefiting from optimal pore structure,N-doping types and percentage of atomic quantity,NC-1000 exhibits superior electrochemical performance:high capacity(248.6 mAh/g at 1 A/g),outstanding rate capability(86.1 mAh/g retained at 20 A/g),and exceptional cycling stability(90%capacity retention after 16000 cycles at 10 A/g).In conclusion,rational pore design and surface composition regulation significantly enhance the performance of porous carbon-based Zn-I_(2) batteries.
作者
周文
贾德东
沈泽龙
桑元华
何孝军
ZHOU Wen;JIA Dedong;SHEN Zelong;SANG Yuanhua;HE Xiaojun(School of Chemistry and Chemical Engineering,Anhui University of Technology,Maanshan 243002,China;State Key Lab of Crystal Materials,Shandong University,Jinan 250100,China)
出处
《洁净煤技术》
北大核心
2025年第12期243-252,共10页
Clean Coal Technology
基金
国家自然科学基金资助项目(52372037)
安徽省自然科学基金资助项目(2408085MB032)
山东大学晶体材料国家重点实验室开放课题资助项目(KF2403)。
关键词
MOFs衍生碳
氮掺杂
多级孔
锌碘电池
正极材料
MOFs-derived carbon
N-doped
hierarchically porous
Zn-I_(2)batteries
cathode materials
