Ceramic synthesis of disordered lithium rich oxyfluoride materials

JOURNAL OF POWER SOURCES

卷:467

Article

Mba, Jean-Marcel Ateba¹  Arcon, Iztok^2,3  Mali, Gregor¹  Tchernychova, Elena¹  Witte, Ralf⁴  Kruk, Robert⁴  Gaberscek, Miran^1,5  Dominko, Robert^1,5,6 

[1] Natl Inst Chem, Hajdrihova 19, Ljubljana 1000, Slovenia

[2] Univ Nova Gorica, Vipayska 13, Nova Gorica 5000, Slovenia

[3] Inst Jozef Stefan, Jamova 39, Ljubljana 1000, Slovenia

[4] Karlsruhe Inst Technol, Inst Nanotechnol, D-76344 Eggenstein Leopoldshafen, Germany

[5] Univ Ljubljana, FKKT, Vecna Pot 117, Ljubljana 1000, Slovenia

[6] FR3104, ALISTORE ERI, F-80039 Amiens, France

关键词: Lithium batteries;    Face centered-cubic;    Oxyfluoride;    Li-rich;    Disorder;   

DOI  :  10.1016/j.jpowsour.2020.228230

来源: Elsevier

【 摘 要 】

Disordered lithium-rich transition metal oxyfluorides with a general formula Li1+xMO2Fx (M being a transition metal) are gaining more attention due to their high specific capacity which can be delivered from the face-centered cubic (fcc) structure. The most common synthesis procedure involves use of mechanosynthesis. In this work, ceramic synthesis of lithium rich iron oxyfluoride and lithium rich titanium oxyfluoride are reported. Two ceramic synthesis routes are developed each leading to the different level of doping with Li and F and different levels of cationic disorder in the structure. Three different Li1+xMO2Fx samples (x = 0.25, 0.3 and 1) are compared with a sample prepared by mechanochemical synthesis and non-doped LiFeO2 with fcc structure. The obtained lithium rich iron oxyfluoride are characterized by use of Mossbauer spectroscopy, X-ray absorption spectroscopy, NMR and TEM. Successful incorporation of Li and F have been confirmed and specific capacity that can be obtained from the samples is in the correlation with the level of disorder introduced with doping, nevertheless oxidation state of iron in all samples is very similar. Conclusions obtained from lithium rich iron oxyfluoride are validated by lithium rich titanium oxyfluoride.

【 授权许可】

Free