LiSixMn2−xO4 (x≤0.10) cathode materials with improved electrochemical properties prepared via a simple solid-state method for high-performance lithium-ion batteries. Issue 12 (September 2016)

• Record Type: Journal Article
• Authors: Zhao, Hongyuan; Liu, Shanshan; Wang, Zhenwei; Cai, Yu; Tan, Ming; Liu, Xingquan
• Is Part Of: Ceramics international. Volume 42:Issue 12(2016)
• Page Start: 13442
• Page End: 13448
• Publication Date: 2016-09
• Subjects: Lithium-ion battery -- LiMn2O4 -- Si-doping -- Solid-state method -- Electrochemical evaluation; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.05.131
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: LiSix Mn2−x O4 (x≤0.10) cathode materials were prepared via a simple solid-state process with tetraethylorthosilicate (TEOS) as the silicon source. The effects of Si-doping on the structure, morphology and electrochemical performance were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge-discharge tests and electrochemical impedance spectroscopy (EIS), respectively. All the Si-doped LiMn2 O4 samples showed the intrinsic spinel structure. With the increasing of Si-doping concentration, the crystal lattice constant of LiSix Mn2−x O4 samples increased and the particle size distribution becomes more uniform to some extent. Among these samples, the optimal Si-doped LiMn2 O4 exhibited an initial discharge capacity of 134.6 mAh g −1 at 0.5 C, which was higher than that of the undoped spinel. After 100 cycles, the discharge capacity could still reach up to 114.5 mAh g −1 with capacity retention of 85.1%. Especially, at the high rate of 5.0 C, a high discharge capacity of 87.5 mAh g −1 was obtained while the undoped spinel only exhibited 33.7 mAh g −1 . Such high performance indicated that doping the manganese sites with appropriate amount of silicon ions could effectively improve the specific capacity and cycling stability.