Atomic surface reduction of interfaces utilizing vapor phase approach: High energy LiNixMnyCoz oxide as a test case
| Autor: | Kevin Leung, Lothar Houben, Michal Leskes, Rosy, Eliran Evenstein, Malachi Noked, Shira Haber, Hadar Sclar |
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| Rok vydání: | 2019 |
| Předmět: |
Work (thermodynamics)
Materials science Renewable Energy Sustainability and the Environment Oxide Energy Engineering and Power Technology 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Cathode 0104 chemical sciences law.invention Amorphous solid chemistry.chemical_compound Chemical engineering X-ray photoelectron spectroscopy chemistry law Surface modification General Materials Science 0210 nano-technology Layer (electronics) |
| Zdroj: | Energy Storage Materials. 19:261-269 |
| ISSN: | 2405-8297 |
| Popis: | In the present work, a simple and agile methodology for atomic surface reduction of interfaces is introduced. Using a surface directed vapor phase reaction, at relatively low temperature, we show that a highly reactive and volatile molecule can be used to selectively reduce the interface, without changing the bulk of the treated material, and without the need of alternating sequence of multiple precursors, normally involved in ALD. The model system we use to demonstrate the efficacy, and potential of our approach is trimethyl aluminum, and high energy Li and Mn rich cathode (HE-NCM) as the functional material of interest. We demonstrate that with the proposed method, the particles of HE-NMC were conformally coated with ~ 3 nm amorphous layer of the reduced surface in less than 1 h (including the cooling time),as witnessed using HR-TEM. XPS and solid-state NMR, further confirmed that surface treatment was successfully achieved using the proposed method and is well explained by DFT calculations. Utilizing online electrochemical mass spectrometry (OEMS), we show in-operando that this amorphous layer helps to suppress parasitic reactions under extreme electrochemical conditions as indicated by the significant reduction in oxygen and CO2 evolution. The surface treatment further resulted in enhancement in specific capacity during the first cycle. This methodology provides a non-conventional path to achieve thin layer surface modification under facile conditions, and opens a new way to meet the requirements of surface modification strategies for improving the performance of electrode materials without utilizing expensive instrumentation and high temperature processes. |
| Databáze: | OpenAIRE |
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