{"title":"Molecular Level Heterojunction with Sulfur Vacancy of Stable Polyhedral Star Configuration for Boosting Hydroxide Ion Storage","authors":"","doi":"10.1016/j.ensm.2024.103681","DOIUrl":null,"url":null,"abstract":"<p>The sluggish diffusion of electrons/OH<sup>−</sup> and poor structural stability restrict the OH<sup>−</sup> reaction kinetic of metal sulfides for supercapacitors. Herein, a molecular level NiS/Co<sub>9</sub>S<sub>8</sub> heterojunction with sulfur vacancy (S<sub>V</sub>) and nitrogen-doped carbon (NC) polyhedral star configuration composites (PS-NiS/Co<sub>9</sub>S<sub>8</sub>@NC) was derived from co-precipitated metal-organic framework (MOF) via in situ ion competitive vulcanization and carbonization strategies. Experiment and theoretical calculations show that the polyhedral star nanostructure with heterojunction exposes more active sites, while the triangular structure covered with NC layer in PS-NiS/Co<sub>9</sub>S<sub>8</sub>@NC composite plays a favorable supporting function for durable OH<sup>−</sup> storage. The NiS/Co<sub>9</sub>S<sub>8</sub> heterojunction, S<sub>V</sub>, and NC coatings synergically optimize the electronic environment and enhance the conductivity. More importantly, the charge redistribution that occurs at NiS/Co<sub>9</sub>S<sub>8</sub> can induce a built-in electric field, significantly reducing the OH<sup>−</sup> diffusion energy barrier and boosting the migration kinetics of electrons/OH<sup>−</sup>. The prepared PS-NiS/Co<sub>9</sub>S<sub>8</sub>@NC exhibits high reversible capacitance (1902 F g<sup>−1</sup> at 1 A g<sup>−1</sup>), excellent rate capacitance (1212 F g<sup>−1</sup> at 30 A g<sup>−1</sup>), and reliable cycle stability (80.1% retention after 7000 cycles). The assembled hybrid device displays an outstanding energy/power output (54.3 Wh kg<sup>−1</sup> and 12706.9 W kg<sup>−1</sup>). Our work provides a promising way to reasonable design between the structure and function for stable OH<sup>−</sup> storage.</p>","PeriodicalId":306,"journal":{"name":"Energy Storage Materials","volume":null,"pages":null},"PeriodicalIF":18.9000,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Energy Storage Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1016/j.ensm.2024.103681","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The sluggish diffusion of electrons/OH− and poor structural stability restrict the OH− reaction kinetic of metal sulfides for supercapacitors. Herein, a molecular level NiS/Co9S8 heterojunction with sulfur vacancy (SV) and nitrogen-doped carbon (NC) polyhedral star configuration composites (PS-NiS/Co9S8@NC) was derived from co-precipitated metal-organic framework (MOF) via in situ ion competitive vulcanization and carbonization strategies. Experiment and theoretical calculations show that the polyhedral star nanostructure with heterojunction exposes more active sites, while the triangular structure covered with NC layer in PS-NiS/Co9S8@NC composite plays a favorable supporting function for durable OH− storage. The NiS/Co9S8 heterojunction, SV, and NC coatings synergically optimize the electronic environment and enhance the conductivity. More importantly, the charge redistribution that occurs at NiS/Co9S8 can induce a built-in electric field, significantly reducing the OH− diffusion energy barrier and boosting the migration kinetics of electrons/OH−. The prepared PS-NiS/Co9S8@NC exhibits high reversible capacitance (1902 F g−1 at 1 A g−1), excellent rate capacitance (1212 F g−1 at 30 A g−1), and reliable cycle stability (80.1% retention after 7000 cycles). The assembled hybrid device displays an outstanding energy/power output (54.3 Wh kg−1 and 12706.9 W kg−1). Our work provides a promising way to reasonable design between the structure and function for stable OH− storage.
期刊介绍:
Energy Storage Materials is a global interdisciplinary journal dedicated to sharing scientific and technological advancements in materials and devices for advanced energy storage and related energy conversion, such as in metal-O2 batteries. The journal features comprehensive research articles, including full papers and short communications, as well as authoritative feature articles and reviews by leading experts in the field.
Energy Storage Materials covers a wide range of topics, including the synthesis, fabrication, structure, properties, performance, and technological applications of energy storage materials. Additionally, the journal explores strategies, policies, and developments in the field of energy storage materials and devices for sustainable energy.
Published papers are selected based on their scientific and technological significance, their ability to provide valuable new knowledge, and their relevance to the international research community.