Structure and cycle stability of SrHPO sub(4)-coated LiMn sub(2)O sub(4) cathode materials for lithium-ion batteries

• Published in: Electrochimica acta Vol. 145; pp. 201 - 208
• Main Authors: Zhang, Xiusheng, Xu, Yunlong, Zhang, Huang, Zhao, Chongjun, Qian, Xiuzhen
• Format: Journal Article
• Language: English
• Published: 01.11.2014
• Subjects: Coating; Coprecipitation; Cycles; Diffraction; Dissolution; High temperature; Lithium-ion batteries; Scanning electron microscopy; Stabilization
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2014.08.043

The SrHPO sub(4)-coated LiMn sub(2)O sub(4) composite materials are prepared through co-precipitation method. The phase structures and morphologies of pristine and SrHPO sub(4) coated LiMn sub(2)O sub(4) are characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The cycling performances are thoroughly investigated and discussed both at room and elevated temperature. The results indicate that 2.0wt% SrHPO sub(4) coated LiMn sub(2)O sub(4) can efficiently improve the cycling performance with capacity retention of 92.3% and 83.6% under room temperature (25 degree C) and elevated temperature (55 degree C) after 100 cycles at 1 C rate, respectively, which are much better than those of the pristine materials. The CV, EIS and XRF measurements reveal that the enhanced stabilization in the cycling performance can be attributed to the suppression of manganese dissolution into electrolyte with the contribution of SrHPO sub(4) coating on the surface of LiMn sub(2)O sub(4).