{"title":"无 \"死锰 \"和腐蚀的 MnO2/Mn2+ 化学离子锚定策略","authors":"Xilong Li, Kaiwen Qi, Zili Qin, Xuan Ding, Yongchun Zhu, Zhiguo Hou, Yitai Qian","doi":"10.1021/acsnano.4c09761","DOIUrl":null,"url":null,"abstract":"The utilization of MnO<sub>2</sub>/Mn<sup>2+</sup> chemistry in near-neutral pH acetate aqueous electrolytes provides an opportunity to achieve a higher energy density (theoretical capacity 616 mA h/g, discharge platform >1.5 V). However, this Zn-MnO<sub>2</sub> aqueous battery suffers from inevitable “dead Mn” and proton corrosion. In this study, we discover that the diffusion of the cathode reaction intermediate Mn<sup>3+</sup> is intrinsic for the generation of “dead Mn”, and the accumulation of “dead Mn” increases the H<sup>+</sup> which shuttles to the anode, inducing serious corrosion. A pH-neutral hydrogel ion-anchored strategy is proposed here not only to restrict the diffusion of Mn<sup>3+</sup> but also to suppress the proton transference. This hydrogel ion anchor is designed by deprotonating a series of monomers undergoing in situ free radical polymerization at the cathode interface. The anionic monomer with a moderate binding energy to manganese ions is screened to anchor Mn<sup>3+</sup>, which enhances the reversibility of the MnO<sub>2</sub>/Mn<sup>2+</sup> reaction. Simultaneously, a substantial amount of anionic groups and hydrophilic functional groups in the hydrogel effectively constrains the proton shuttle to corrode the anode. Consequently, the Zn/MnO<sub>2</sub> battery achieves exceptional cyclic stability of the MnO<sub>2</sub>/Mn<sup>2+</sup> reaction, sustaining 8500 cycles even at a relatively low current density and discharge current density of 1 mA/cm<sup>2</sup>. Our findings highlight the importance of anchoring Mn<sup>3+</sup> at the cathode interface and offer valuable insights for advancing practical applications of MnO<sub>2</sub>/Mn<sup>2+</sup> reactions.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":null,"pages":null},"PeriodicalIF":15.8000,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Ion-Anchored Strategy for MnO2/Mn2+ Chemistry without “Dead Mn” and Corrosion\",\"authors\":\"Xilong Li, Kaiwen Qi, Zili Qin, Xuan Ding, Yongchun Zhu, Zhiguo Hou, Yitai Qian\",\"doi\":\"10.1021/acsnano.4c09761\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The utilization of MnO<sub>2</sub>/Mn<sup>2+</sup> chemistry in near-neutral pH acetate aqueous electrolytes provides an opportunity to achieve a higher energy density (theoretical capacity 616 mA h/g, discharge platform >1.5 V). However, this Zn-MnO<sub>2</sub> aqueous battery suffers from inevitable “dead Mn” and proton corrosion. In this study, we discover that the diffusion of the cathode reaction intermediate Mn<sup>3+</sup> is intrinsic for the generation of “dead Mn”, and the accumulation of “dead Mn” increases the H<sup>+</sup> which shuttles to the anode, inducing serious corrosion. A pH-neutral hydrogel ion-anchored strategy is proposed here not only to restrict the diffusion of Mn<sup>3+</sup> but also to suppress the proton transference. This hydrogel ion anchor is designed by deprotonating a series of monomers undergoing in situ free radical polymerization at the cathode interface. The anionic monomer with a moderate binding energy to manganese ions is screened to anchor Mn<sup>3+</sup>, which enhances the reversibility of the MnO<sub>2</sub>/Mn<sup>2+</sup> reaction. Simultaneously, a substantial amount of anionic groups and hydrophilic functional groups in the hydrogel effectively constrains the proton shuttle to corrode the anode. Consequently, the Zn/MnO<sub>2</sub> battery achieves exceptional cyclic stability of the MnO<sub>2</sub>/Mn<sup>2+</sup> reaction, sustaining 8500 cycles even at a relatively low current density and discharge current density of 1 mA/cm<sup>2</sup>. Our findings highlight the importance of anchoring Mn<sup>3+</sup> at the cathode interface and offer valuable insights for advancing practical applications of MnO<sub>2</sub>/Mn<sup>2+</sup> reactions.\",\"PeriodicalId\":21,\"journal\":{\"name\":\"ACS Nano\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":15.8000,\"publicationDate\":\"2024-09-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"ACS Nano\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://doi.org/10.1021/acsnano.4c09761\",\"RegionNum\":1,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Nano","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1021/acsnano.4c09761","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Ion-Anchored Strategy for MnO2/Mn2+ Chemistry without “Dead Mn” and Corrosion
The utilization of MnO2/Mn2+ chemistry in near-neutral pH acetate aqueous electrolytes provides an opportunity to achieve a higher energy density (theoretical capacity 616 mA h/g, discharge platform >1.5 V). However, this Zn-MnO2 aqueous battery suffers from inevitable “dead Mn” and proton corrosion. In this study, we discover that the diffusion of the cathode reaction intermediate Mn3+ is intrinsic for the generation of “dead Mn”, and the accumulation of “dead Mn” increases the H+ which shuttles to the anode, inducing serious corrosion. A pH-neutral hydrogel ion-anchored strategy is proposed here not only to restrict the diffusion of Mn3+ but also to suppress the proton transference. This hydrogel ion anchor is designed by deprotonating a series of monomers undergoing in situ free radical polymerization at the cathode interface. The anionic monomer with a moderate binding energy to manganese ions is screened to anchor Mn3+, which enhances the reversibility of the MnO2/Mn2+ reaction. Simultaneously, a substantial amount of anionic groups and hydrophilic functional groups in the hydrogel effectively constrains the proton shuttle to corrode the anode. Consequently, the Zn/MnO2 battery achieves exceptional cyclic stability of the MnO2/Mn2+ reaction, sustaining 8500 cycles even at a relatively low current density and discharge current density of 1 mA/cm2. Our findings highlight the importance of anchoring Mn3+ at the cathode interface and offer valuable insights for advancing practical applications of MnO2/Mn2+ reactions.
期刊介绍:
ACS Nano, published monthly, serves as an international forum for comprehensive articles on nanoscience and nanotechnology research at the intersections of chemistry, biology, materials science, physics, and engineering. The journal fosters communication among scientists in these communities, facilitating collaboration, new research opportunities, and advancements through discoveries. ACS Nano covers synthesis, assembly, characterization, theory, and simulation of nanostructures, nanobiotechnology, nanofabrication, methods and tools for nanoscience and nanotechnology, and self- and directed-assembly. Alongside original research articles, it offers thorough reviews, perspectives on cutting-edge research, and discussions envisioning the future of nanoscience and nanotechnology.