Mitigating oxygen release in anionic-redox-active cathode materials by cationic substitution through rational design
| Autor: | Derek Lau, Ying Shirley Meng, Minghao Zhang, Chengcheng Fang, Haodong Liu, Jungwoo Z. Lee, Thomas A. Wynn, Xuefeng Wang, Kuan-Zong Fung, Chung Ta Ni, Bo-Yuan Huang, Daniel M. Davies |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
chemistry.chemical_element 02 engineering and technology 010402 general chemistry Photochemistry Electrochemistry 01 natural sciences Redox Oxygen Macromolecular and Materials Chemistry Condensed Matter::Materials Science Transition metal General Materials Science Physics::Chemical Physics Dopant Renewable Energy Sustainability and the Environment Charge density Materials Engineering General Chemistry 021001 nanoscience & nanotechnology 0104 chemical sciences chemistry Lithium Density functional theory Interdisciplinary Engineering 0210 nano-technology |
| Zdroj: | Wynn, Thomas A; Fang, Chengcheng; Zhang, Minghao; Liu, Haodong; Davies, Daniel M; Wang, Xuefeng; et al.(2018). Mitigating oxygen release in anionic-redox-active cathode materials by cationic substitution through rational design. Journal of Materials Chemistry A, 6(47), 24651-24659. doi: 10.1039/c8ta06296j. UC San Diego: Retrieved from: http://www.escholarship.org/uc/item/2k87g357 JOURNAL OF MATERIALS CHEMISTRY A, vol 6, iss 47 Journal of Materials Chemistry A, vol 6, iss 47 |
| DOI: | 10.1039/c8ta06296j. |
| Popis: | When substituting excess lithium in the transition metal layer, oxygen extends its role as a framework in classical layered oxide cathodes, exhibiting electrochemical activity and enhancing the reversible capacities of layered oxides through anionic redox mechanisms. However, oxygen activity comes with instability in the form of oxygen loss, which is associated with irreversible voltage decay and capacity fade. To understand this irreversible loss and to increase the stability of lattice oxygen, density functional theory is applied to calculate oxygen vacancy formation energies in lithium rich transition metal layered oxides for a variety of dopants, noting increased stability upon doping with 4d elements Mo and Ru. Driven by these findings, Mo is co-doped with Co into Li[Li0.2Ni0.2Mn0.6]O2, showing notably reduced voltage decay and capacity fade without sacrificing energy density and cycle life, and the evidence of Mo incorporation is presented. Calculations suggest that this is due to a modified charge density distribution around anions upon incorporation of Mo, altering the local band structure and impeding oxygen vacancy formation, while maintaining the anionic activity available for redox. |
| Databáze: | OpenAIRE |
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