Enhanced Lithium-Ion Storage through Anchoring Nanocrystalline MoO2/C Microspheres in rGO Nanosheets: Boosting Pseudocapacitance and Facilitating Rapid Conversion

IF 5.8 2区 材料科学 Q2 CHEMISTRY, PHYSICAL
Jie Min, Sijie Liu, Zejun Deng, Rui Zhang, Weili Zhang, Jun Liu, Jianjun Chen
{"title":"Enhanced Lithium-Ion Storage through Anchoring Nanocrystalline MoO2/C Microspheres in rGO Nanosheets: Boosting Pseudocapacitance and Facilitating Rapid Conversion","authors":"Jie Min, Sijie Liu, Zejun Deng, Rui Zhang, Weili Zhang, Jun Liu, Jianjun Chen","doi":"10.1016/j.jallcom.2024.177899","DOIUrl":null,"url":null,"abstract":"Both crystalline and amorphous MoO<sub>2</sub> exhibit distinct advantages for lithium-ion battery applications, with the former favoring lithium-ion intercalation and the latter undergoing complete lithiation <em>via</em> a conversion reaction. However, their sluggish lithium-ion insertion rates and inadequate charge transfer kinetics hinder their full potential. To address these challenges, we have developed a controllable approach that integrates liquid-phase dispersion of the H<sub>x</sub>MoO<sub>3</sub>/C and graphene oxides (GO) precursors followed by freeze-drying and low-temperature calcinations, aiming to merit the ionic conductivity of MoO<sub>2</sub>/C nanocrystallite and the electronic conductivity of reduce graphene oxides (rGO), respectively. This facile method yields bubble-sheet-like MoO<sub>2</sub>/C@rGO composites, where the quantitatively strategic incorporation of rGO can effectively mitigate recrystallization and surface oxidation of MoO<sub>2</sub> nanocrystals. Furthermore, the approximately 70% volume shrinkage of H<sub>x</sub>MoO<sub>3/</sub>C precursors into MoO<sub>2</sub>/C can create a flexible void space between the microspheres and the rGO coating for better accommodating volume variations during lithiation. Electrochemical measurements show that MoO<sub>2</sub>/C@rGO delivers high initial coulombic efficiency (ICE, <em>e.g.</em>, up to 71.3% at 100<!-- --> <!-- -->mA<!-- --> <!-- -->g⁻¹), impressive rate performance (<em>e.g.</em>, achieving 60 mAh g⁻¹ at 1<!-- --> <!-- -->A<!-- --> <!-- -->g⁻¹, and 34.1% retention from 0.1 to 2<!-- --> <!-- -->A<!-- --> <!-- -->g⁻¹) and excellent cyclability (<em>e.g.</em>, retaining 98.9% of its capacity after 200 cycles) when employed as an intercalation-type anode material above 1.00<!-- --> <!-- -->V (<em>vs.</em> Li/Li⁺). Remarkably, electrochemical analysis indicates that the capacitive contribution is dominant during high-rate applications (<em>e.g.</em>, up to 73.06% ratio at a scan rate of 0.50<!-- --> <!-- -->mV<!-- --> <!-- -->s⁻¹), exhibiting a pseudocapacitive behavior. Additionally, MoO<sub>2</sub>/C@rGO exhibits enhanced ICE (<em>e.g.</em>, up to 76.9% at 100<!-- --> <!-- -->mA<!-- --> <!-- -->g⁻¹), accelerated activation (<em>e.g.</em>, achieving peak performance within 10 cycles at 100<!-- --> <!-- -->mA<!-- --> <!-- -->g⁻¹), superior rate performance (<em>e.g.</em>, achieving 446 mAh g⁻¹ at 2<!-- --> <!-- -->A<!-- --> <!-- -->g⁻¹), and remarkable cyclability (<em>e.g.</em>, maintaining 510 mAh g⁻¹ with 88.9% capacity retention over 600 cycles at 1<!-- --> <!-- -->A<!-- --> <!-- -->g⁻¹) when applied as a conversion-type anode material at between 1.00 to 3.00<!-- --> <!-- -->V (<em>vs.</em> Li/Li⁺). To elucidate the mechanisms underlying the high-rate performance and the increased capacity, <em>ex-situ</em> XRD, <em>ex-situ</em> SEM, <em>ex-situ</em> TEM, and electrochemical analysis were carried out. No evident phase transition or material pulverization can be observed upon cycling above 1.00<!-- --> <!-- -->V; therefore, the structural evolution is entirely single-phase or solid-solution, which accompanies with pseudocapacitive characteristic. However, the diffraction peaks downshift, the eminent of Li<sub>x</sub>MoO<sub>2+δ</sub>, the pulverization, and the gradual amorphization of MoO<sub>2</sub> can be observed upon cycling, indicating an sequential intercalation-to-conversion activation from a crystalline state to an amorphous state.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"37 1","pages":""},"PeriodicalIF":5.8000,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Alloys and Compounds","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1016/j.jallcom.2024.177899","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0

Abstract

Both crystalline and amorphous MoO2 exhibit distinct advantages for lithium-ion battery applications, with the former favoring lithium-ion intercalation and the latter undergoing complete lithiation via a conversion reaction. However, their sluggish lithium-ion insertion rates and inadequate charge transfer kinetics hinder their full potential. To address these challenges, we have developed a controllable approach that integrates liquid-phase dispersion of the HxMoO3/C and graphene oxides (GO) precursors followed by freeze-drying and low-temperature calcinations, aiming to merit the ionic conductivity of MoO2/C nanocrystallite and the electronic conductivity of reduce graphene oxides (rGO), respectively. This facile method yields bubble-sheet-like MoO2/C@rGO composites, where the quantitatively strategic incorporation of rGO can effectively mitigate recrystallization and surface oxidation of MoO2 nanocrystals. Furthermore, the approximately 70% volume shrinkage of HxMoO3/C precursors into MoO2/C can create a flexible void space between the microspheres and the rGO coating for better accommodating volume variations during lithiation. Electrochemical measurements show that MoO2/C@rGO delivers high initial coulombic efficiency (ICE, e.g., up to 71.3% at 100 mA g⁻¹), impressive rate performance (e.g., achieving 60 mAh g⁻¹ at 1 A g⁻¹, and 34.1% retention from 0.1 to 2 A g⁻¹) and excellent cyclability (e.g., retaining 98.9% of its capacity after 200 cycles) when employed as an intercalation-type anode material above 1.00 V (vs. Li/Li⁺). Remarkably, electrochemical analysis indicates that the capacitive contribution is dominant during high-rate applications (e.g., up to 73.06% ratio at a scan rate of 0.50 mV s⁻¹), exhibiting a pseudocapacitive behavior. Additionally, MoO2/C@rGO exhibits enhanced ICE (e.g., up to 76.9% at 100 mA g⁻¹), accelerated activation (e.g., achieving peak performance within 10 cycles at 100 mA g⁻¹), superior rate performance (e.g., achieving 446 mAh g⁻¹ at 2 A g⁻¹), and remarkable cyclability (e.g., maintaining 510 mAh g⁻¹ with 88.9% capacity retention over 600 cycles at 1 A g⁻¹) when applied as a conversion-type anode material at between 1.00 to 3.00 V (vs. Li/Li⁺). To elucidate the mechanisms underlying the high-rate performance and the increased capacity, ex-situ XRD, ex-situ SEM, ex-situ TEM, and electrochemical analysis were carried out. No evident phase transition or material pulverization can be observed upon cycling above 1.00 V; therefore, the structural evolution is entirely single-phase or solid-solution, which accompanies with pseudocapacitive characteristic. However, the diffraction peaks downshift, the eminent of LixMoO2+δ, the pulverization, and the gradual amorphization of MoO2 can be observed upon cycling, indicating an sequential intercalation-to-conversion activation from a crystalline state to an amorphous state.

Abstract Image

通过在氧化石墨烯纳米片中锚定纳米晶MoO2/C微球增强锂离子存储:提高赝电容并促进快速转换
晶态和非晶态MoO2在锂离子电池应用中都具有明显的优势,前者有利于锂离子嵌入,后者通过转化反应完全锂化。然而,它们缓慢的锂离子插入率和不充分的电荷转移动力学阻碍了它们充分发挥潜力。为了解决这些挑战,我们开发了一种可控的方法,将HxMoO3/C和氧化石墨烯(GO)前驱体的液相分散,然后进行冷冻干燥和低温煅烧,旨在分别获得MoO2/C纳米晶体的离子电导率和还原氧化石墨烯(rGO)的电子电导率。这种简单的方法产生了气泡片状的MoO2/C@rGO复合材料,其中定量战略性地加入还原氧化石墨烯可以有效地减轻MoO2纳米晶体的再结晶和表面氧化。此外,HxMoO3/C前驱体约70%的体积收缩成MoO2/C,可以在微球和氧化石墨烯涂层之间创造一个灵活的空隙空间,从而更好地适应锂化过程中的体积变化。电化学测量表明,MoO2/C@rGO具有很高的初始库仑效率(ICE,例如,在100 mA g⁻¹时高达71.3%),惊人的速率性能(例如,在1 mA g⁻¹时达到60 mAh g⁻¹,在0.1到2 mA g⁻¹时保持34.1%的容量)和出色的可循环性(例如,在200次循环后保持98.9%的容量),当用作插层型阳极材料时高于1.00 V(与Li/Li +相比)。值得注意的是,电化学分析表明,在高速率应用中,电容性贡献占主导地位(例如,在0.50 mV s的扫描速率下,高达73.06%的比例),表现出假电容性行为。此外,MoO2/C@rGO表现出增强的ICE(例如,在100 mA g⁻¹下高达76.9%),加速的活化(例如,在100 mA g⁻¹下在10个循环内达到峰值性能),卓越的速率性能(例如,在2 mA g⁻¹下达到446 mAh g⁻¹),以及卓越的循环性能(例如,在1 A g⁻¹下在600个循环中保持510 mAh g⁻¹和88.9%的容量保留),当作为转换型阳极材料应用于1.00到3.00 V之间时(与Li/Li +相比)。为了阐明高速率性能和容量增加的机制,进行了非原位XRD,非原位SEM,非原位TEM和电化学分析。在1.00 V以上循环时,未观察到明显的相变或材料粉碎;因此,结构演变完全是单相或固溶的,并伴有赝电容特性。然而,在循环过程中,可以观察到衍射峰的下移、LixMoO2+δ的突出、MoO2的粉化和逐渐非晶化,表明从晶态到非晶态的连续插层到转换活化。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Journal of Alloys and Compounds
Journal of Alloys and Compounds 工程技术-材料科学:综合
CiteScore
11.10
自引率
14.50%
发文量
5146
审稿时长
67 days
期刊介绍: The Journal of Alloys and Compounds is intended to serve as an international medium for the publication of work on solid materials comprising compounds as well as alloys. Its great strength lies in the diversity of discipline which it encompasses, drawing together results from materials science, solid-state chemistry and physics.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信