We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Lithium/Oxygen Incorporation and Microstructural Evolution during Synthesis of Li‐Rich Layered Li[Li<sub>0.2</sub>Ni<sub>0.2</sub>Mn<sub>0.6</sub>]O<sub>2</sub> Oxides.
- Authors
Hua, Weibo; Chen, Mingzhe; Schwarz, Björn; Knapp, Michael; Bruns, Michael; Barthel, Juri; Yang, Xiushan; Sigel, Florian; Azmi, Raheleh; Senyshyn, Anatoliy; Missiul, Alkesandr; Simonelli, Laura; Etter, Martin; Wang, Suning; Mu, Xiaoke; Fiedler, Andy; Binder, Joachim R.; Guo, Xiaodong; Chou, Shulei; Zhong, Benhe
- Abstract
As promising cathode materials, the lithium‐excess 3d‐transition‐metal layered oxides can deliver much higher capacities (>250 mAh g−1 at 0.1 C) than the current commercial layered oxide materials (≈180 mAh g−1 at 0.1 C) used in lithium ion batteries. Unfortunately, the original formation mechanism of these layered oxides during synthesis is not completely elucidated, that is, how is lithium and oxygen inserted into the matrix structure of the precursor during lithiation reaction? Here, a promising and practical method, a coprecipitation route followed by a microwave heating process, for controllable synthesis of cobalt‐free lithium‐excess layered compounds is reported. A series of the consistent results unambiguously confirms that oxygen atoms are successively incorporated into the precursor obtained by a coprecipitation process to maintain electroneutrality and to provide the coordination sites for inserted Li ions and transition metal cations via a high‐temperature lithiation. It is found that the electrochemical performances of the cathode materials are strongly related to the phase composition and preparation procedure. The monoclinic layered Li[Li0.2Ni0.2Mn0.6]O2 cathode materials with state‐of‐the‐art electrochemical performance and comparably high discharge capacities of 171 mAh g−1 at 10 C are obtained by microwave annealing at 750 °C for 2 h. Structural evolution from a precursor obtained by a hydroxide coprecipitation method to Co‐free Li‐excess layered Li[Li0.2Ni0.2Mn0.6]O2 (LLNMO) oxides is presented. The intermediate state consisting of coherent layered and spinel/rock‐salt‐type phases is observed directly on a single crystallite. A promising microwave‐assisted technique for preparing LLNMOs with high performance is proposed. The origin of oxygen incorporation during synthesis of LLNMOs is unraveled.
- Subjects
LITHIUM-ion batteries; ELECTROCHEMICAL electrodes; COPRECIPITATION (Chemistry); METAL microstructure; LITHIATION
- Publication
Advanced Energy Materials, 2019, Vol 9, Issue 8, pN.PAG
- ISSN
1614-6832
- Publication type
Article
- DOI
10.1002/aenm.201803094