Details

Autor(en) / Beteiligte

• Luo, Ying
• Li, Haiyan
• Lu, Taolin
• Zhang, Yixiao
• Mao, Samuel S
• Liu, Zhi
• Wen, Wen
• Xie, Jingying
• Yan, Liqin

Titel

Fluorine gradient-doped LiNi^sub 0.5^Mn^sub 1.5^O^sub 4^ spinel with improved high voltage stability for Li-ion batteries

Ist Teil von

• Electrochimica acta, 2017-06, Vol.238, p.237

Ort / Verlag

Oxford: Elsevier BV

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The fluorine gradient-doped LiNi0.5Mn1.5O4 spinels are synthesized by a facile one-step method and the effect of heat treatment on their structure, morphology, and electrochemical performance are investigated. The results show that introduction of fluorine leads to a larger lattice parameter and particle size, and the formation of F-enriched surface. Whereas at 400 °C, the fluorine gradient-doped LiNi0.5Mn1.5O4 sample exhibits an improved long-term cycling stability and high rate performance, due to the suppression of the reaction between electrolyte and cathode, resulting in a decrease in the total resistance and the formation of a thin, uniform and smooth film on the surface. As a result of in situ XRD with charged pristine and the fluorine gradient-doped samples, the similar thermal-decomposition pathways from the charged spinel to the final NiMn2O4-type spinel structure with a small amount of NiMnO3 and α-Mn2O3 are observed. In addition, the disappearance temperature of the charged spinel structures is at about 280 °C for the fluorine gradient-doped sample, exhibiting an improved thermal stability of high voltage cathode material. These results show that fluorine gradient-doped LiNi0.5Mn1.5O4 sample is a promising positive electrode material for high performance lithium ion batteries.