Electrochemical properties and microstructures of LiMn2O4 cathodes coated with aluminum zirconium coupling agents. Issue 9 (15th June 2020)

• Record Type: Journal Article
• Authors: Wang, Sunfa; Luo, Chengguo; Feng, Yanyan; Fan, Guangxin; Feng, Lanlan; Ren, Mingming; Liu, Baozhong
• Is Part Of: Ceramics international. Volume 46:Issue 9(2020)
• Page Start: 13003
• Page End: 13013
• Publication Date: 2020-06-15
• Subjects: Lithium-ion batteries -- LiMn2O4 cathode -- Aluminum-zirconium coupling agent -- Surface treatment -- Electrochemical performances; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.02.070
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: In this study, we developed a novel and facile modification method to improve the performance of LiMn2 O4 (LMO) electrodes for lithium ion batteries. We used an aluminum-zirconium coupling agent (AZCA) to treat LMO cathodes via a simple pyrolysis method at 450 °C. The microstructures and properties of the cathodes were examined by carrying out X-ray diffraction, scanning electron microscopy, X-ray photoelectron microscopy, transmission electron microscopy, and electrochemical analyses. The results showed that an amorphous Al2 O3 /ZrO2 composite layer was uniformly coated on the surface of the positive material, and the thickness of the coating was about 6 nm. The coating did not affect the particle morphology and crystal structure of the samples. However, it could enhance the surface stability and result in reducing the polarization, improving the rate properties and cycle reversibility of LMO especially at high temperatures. The optimum AZCA amount for the deposition of the composite coating was found to be 3 wt%. After coating, the discharge capacity of LMO at 3C increased by 14.37% and 74.95% at 25 and 55 °C, respectively. Noteworthy, after 100 cycles at 55 °C and 1C rate, the capacity retention of LMO increased from 61.3% to 88.1%. The improvement in the properties of the AZCA-treated LMO cathodes can be attributed to the synergy between Al2 O3 and ZrO2, which improved the chemical stability of the cathode surface, suppressed the side reaction between the cathode and the electrolyte and enhanced the reversible deinsertion/insertion ability of Li + . In addition, the composite coating can greatly stabilize the crystal structure of LMO during charging-discharging cycling.