Two‐position intrinsic element complement: Synthesis and electrochemical properties of Li2 + xMn1‐xSiO4@carbon as cathode materials for lithium batteries. (31st May 2021)

• Record Type: Journal Article
• Authors: Wang, Luoxuan; Zhan, Yang; Luo, Shao‐Hua; Li, Pengwei; Wang, Qing; Zhang, Yahui; Liu, Xin; Chang, Longjiao
• Is Part Of: International journal of energy research. Volume 45:Number 11(2021)
• Page Start: 16922
• Page End: 16931
• Publication Date: 2021-05-31
• Subjects: cathode material -- Li2MnSiO4 -- lithium‐excess chemistry -- lithium‐ion batteries; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.6913
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: Li2 + x Mn1‐x SiO4 compounds with a deficiency and an excess of lithium as a cathode material for Li‐ion batteries were synthesized by the solid‐state synthesis method, and a two‐step calcination process was applied to improve the electrochemical properties. The calcination temperature was determined by the thermogravimetric analysis and differential scanning calorimetry (TG‐DSC) curves. The synthesized compounds were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), and other material testing methods. A MnO and Mn2 SiO4 impurity was detected in the Li2 + x Mn1‐x SiO4 compounds. The cycle performance of Li1.96 Mn1.04 SiO4, Li1.98 Mn1.02 SiO4, and Li2.02 Mn0.98 SiO4 cathode materials for lithium‐ion batteries was tested to compare with that of pure Li2 MnSiO4 . The Li2.02 Mn0.98 SiO4 sample doped with an excess of Li both has a high first discharge specific capacity and excellent electrochemical cycle stability. The introduction of an appropriate strategy to produce a lithium excess is an effective way to improve the electrochemical performance of cathode materials. Abstract : In this paper, low‐valence cation doping was used to improve the electrochemical performance of the Li2 MnSiO4 materials for LIBs. By cation doping, the introduction of Li and other low‐cost metal elements that partially replace Mn can improve the cycle stability performance. The solid‐phase synthesis method was used to dope lithium into the Li2 MnSiO4 cathode materials.