Nanostructured LiMnO2 with Li3PO4 Integrated at the Atomic Scale for High-Energy Electrode Materials with Reversible Anionic Redox,ACS Central Science

当前位置： X-MOL 学术 › ACS Cent. Sci. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Nanostructured LiMnO2 with Li3PO4 Integrated at the Atomic Scale for High-Energy Electrode Materials with Reversible Anionic Redox
ACS Central Science ( IF 12.7 ) Pub Date : 2020-12-15 , DOI: 10.1021/acscentsci.0c01200
Miho Sawamura ₁ , Sho Kobayakawa ₁ , Jun Kikkawa ₂ , Neeraj Sharma ₃ , Damian Goonetilleke ₃ , Aditya Rawal ₄ , Nanaka Shimada ₅ , Kentaro Yamamoto ₆ , Rina Yamamoto ₆ , Yingying Zhou ₆ , Yoshiharu Uchimoto ₆ , Koji Nakanishi ₇ , Kei Mitsuhara ₇ , Koji Ohara ₈ , Jiwon Park ₉ , Hye Ryung Byon ₉ , Hiroaki Koga _{10,

11} , Masaki Okoshi _{10,

11} , Toshiaki Ohta ₇ , Naoaki Yabuuchi _{5,

11,

12}

Affiliation

Department of Applied Chemistry, Tokyo Denki University, 5 Senju Asahi-cho, Adachi-ku, Tokyo 120-8551, Japan
National Institute for Materials Science (NIMS), Namiki, Tsukuba, Ibaraki 305-0044, Japan
School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia
Mark Wainwright Analytical Centre, UNSW Sydney, Sydney, NSW 2052, Australia
Department of Chemistry and Life Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-honmachi, Sakyo, Kyoto 606-8501, Japan
SR Center, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577, Japan
Diffraction and Scattering Division, Center for Synchrotron Radiation Research, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8), Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) and KAIST Institute for NanoCentury, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
Research Organization for Information Science and Technology (RIST), 1-18-16 Hamamatsucho, Minato-ku, Tokyo 105-0013, Japan
Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, f1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
Advanced Chemical Energy Research Center, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan

Nanostructured LiMnO₂ integrated with Li₃PO₄ was successfully synthesized by the mechanical milling route and examined as a new series of positive electrode materials for rechargeable lithium batteries. Although uniform mixing at the atomic scale between LiMnO₂ and Li₃PO₄ was not anticipated because of the noncompatibility of crystal structures for both phases, our study reveals that phosphorus ions with excess lithium ions dissolve into nanosize crystalline LiMnO₂ as first evidenced by elemental mapping using STEM-EELS combined with total X-ray scattering, solid-state NMR spectroscopy, and a theoretical ab initio study. The integrated phase features a low-crystallinity metastable phase with a unique nanostructure; the phosphorus ion located at the tetrahedral site shares faces with adjacent lithium ions at slightly distorted octahedral sites. This phase delivers a large reversible capacity of ∼320 mA h g^–1 as a high-energy positive electrode material in Li cells. The large reversible capacity originated from the contribution from the anionic redox of oxygen coupled with the cationic redox of Mn ions, as evidenced by operando soft XAS spectroscopy, and the superior reversibility of the anionic redox and the suppression of oxygen loss were also found by online electrochemical mass spectroscopy. The improved reversibility of the anionic redox originates from the presence of phosphorus ions associated with the suppression of oxygen dimerization, as supported by a theoretical study. From these results, the mechanistic foundations of nanostructured high-capacity positive electrode materials were established, and further chemical and physical optimization may lead to the development of next-generation electrochemical devices.

中文翻译：

原子尺度集成有Li ₃ PO _4的纳米结构LiMnO ₂用于可逆阴离子氧化还原的高能电极材料

通过机械铣削工艺成功合成了集成有Li ₃ PO _4的纳米结构LiMnO _2，并将其作为可充电锂电池的新系列正极材料进行了研究。尽管由于两相晶体结构的不相容性，无法预期LiMnO ₂和Li ₃ PO ₄在原子尺度上均匀混合，但我们的研究表明，具有过量锂离子的磷离子可溶解成纳米级晶体LiMnO ₂，首先由元素证实使用STEM-EELS结合总X射线散射，固态NMR光谱和理论上的从头算图研究。集成相具有低结晶性亚稳态相，具有独特的纳米结构。位于四面体位置的磷离子与八面体稍微变形的相邻锂离子共享面。该相作为锂电池中的高能正极材料，可逆容量约为320 mA hg ^–1。大的可逆容量源自氧气的阴离子氧化还原与Mn离子的阳离子氧化还原的作用，如操作所证明的那样在线电化学质谱也发现了软XAS光谱，以及阴离子氧化还原的优异可逆性和氧损失的抑制作用。阴离子氧化还原的改善的可逆性源自理论研究支持的磷离子的存在与氧二聚化的抑制有关。从这些结果，建立了纳米结构高容量正极材料的机械基础，并且进一步的化学和物理优化可能导致下一代电化学装置的发展。

更新日期：2020-12-23

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11