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DNP-ssNMR谱研究高能阴极烷基化LixSiyOz界面相的结构与功能
作者:小柯机器人 发布时间:2021/3/27 23:35:48

以色列魏茨曼科学研究院Michal Leskes团队提出了DNP-ssNMR光谱中用于高能阴极的烷基化LixSiyOz界面相的结构和功能研究。 相关研究成果于2021年3月22日发表在国际知名学术期刊《美国化学会杂志》。

阴极-电解质界面的降解过程是高能锂离子充电电池发展的一个主要限制因素。在高能阴极表面沉积保护涂层是控制界面反应的一种很有前途的方法。然而,可探测薄、无序和不均匀相的分析工具限制了有效保护层的合理设计。

该文中,研究人员提出了一种基于固态核磁共振波谱和动态核极化(DNP)相结合的表征薄膜结构的新方法。研究组在一种高效的烷基化LixSiyOz涂层上演示了这种方法。

利用不同的DNP来源、氮氧化物双自由基的外源和顺磁性金属离子掺杂的内源,揭示了沉积的人工界面相的外表面和内表面层,并建立了涂层的结构模型。此外,锂同位素交换实验为表面层的功能提供了直接证据,阐明了其在涂层阴极速率性能增强中的作用。

所提出的方法和结果促进了有效涂层的关键性能的确定,并使保护和离子导电表面层的合理设计成为可能。

附:英文原文

Title: Structure and Functionality of an Alkylated LixSiyOz Interphase for High-Energy Cathodes from DNP-ssNMR Spectroscopy

Author: Shira Haber, Rosy, Arka Saha, Olga Brontvein, Raanan Carmieli, Arava Zohar, Malachi Noked, Michal Leskes

Issue&Volume: March 22, 2021

Abstract: Degradation processes at the cathode–electrolyte interface are a major limitation in the development of high-energy lithium-ion rechargeable batteries. Deposition of protective thin coating layers on the surface of high-energy cathodes is a promising approach to control interfacial reactions. However, rational design of effective protection layers is limited by the scarcity of analytical tools that can probe thin, disordered, and heterogeneous phases. Here we propose a new structural approach based on solid-state nuclear magnetic resonance spectroscopy coupled with dynamic nuclear polarization (DNP) for characterizing thin coating layers. We demonstrate the approach on an efficient alkylated LixSiyOz coating layer. By utilizing different sources for DNP, exogenous from nitroxide biradicals and endogenous from paramagnetic metal ion dopants, we reveal the outer and inner surface layers of the deposited artificial interphase and construct a structural model for the coating. In addition, lithium isotope exchange experiments provide direct evidence for the function of the surface layer, shedding light on its role in the enhanced rate performance of coated cathodes. The presented methodology and results advance us in identifying the key properties of effective coatings and may enable rational design of protective and ion-conducting surface layers.

DOI: 10.1021/jacs.1c00215

Source: https://pubs.acs.org/doi/10.1021/jacs.1c00215

 

期刊信息

JACS:《美国化学会志》,创刊于1879年。隶属于美国化学会,最新IF:14.612
官方网址:https://pubs.acs.org/journal/jacsat
投稿链接:https://acsparagonplus.acs.org/psweb/loginForm?code=1000