General synthesis of nano-M embedded Li4Ti5O12/C composites (M = Sn, Sb and Bi) with high capacity and good cycle stability. (1st November 2016)

• Record Type: Journal Article
• Authors: Zeng, Tianbiao; Hu, Xuebu; Ji, Penghui; Peng, Qimeng; Shang, Biao; Gong, Shiding
• Is Part Of: Electrochimica acta. Volume 217(2016)
• Page Start: 299
• Page End: 309
• Publication Date: 2016-11-01
• Subjects: Li4Ti5O12 -- embedded -- Sn -- Sb -- Bi; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.09.075
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Nano-metal embedded Li4 Ti5 O12 /C composites (Li4 Ti5 O12 /M/C samples labeled as Li4 Ti5 O12 /Sn/C-L, Li4 Ti5 O12 /Sn/C-H, Li4 Ti5 O12 /Sb/C-L, Li4 Ti5 O12 /Sb/C-H, Li4 Ti5 O12 /Bi/C-L and Li4 Ti5 O12 /Bi/C-H, respectively) as high capacity anode were synthesized by sol-gel and high temperature solid state reaction methods. The physical properties of Li4 Ti5 O12 /M/C were detected by X-ray diffraction (XRD), scanning microscopy (SEM), transmission electron microscopy (TEM) and elemental analysis. All composites were completely coated by a thin carbon layer. Besides the Li4 Ti5 O12 /Bi/C-L, other Li4 Ti5 O12 /M/C samples were composed of spherical-like aggregate particles. Nano-M was embedded between inner Li4 Ti5 O12 and outer carbon layer. Their electrochemical performances were studied by galvanostatic cycle and cyclic voltammograms (CVs). These analyses show that Li4 Ti5 O12 /Sn/C-L, Li4 Ti5 O12 /Sn/C-H, Li4 Ti5 O12 /Sb/C-H, Li4 Ti5 O12 /Bi/C-H delivered a reversible capacity of 231.9, 308.1, 235.9 and 213.5 mAh g −1 at 500th cycle on current density of 200 mA g −1, respectively, while Li4 Ti5 O12 /C composite only delivered a capacity of 197.6 mAh g −1 at the same conditions. The results demonstrated that metal M can play an important role on high capacity performance of Li4 Ti5 O12 -based anode when it was embedded between inner "zero-strain" Li4 Ti5 O12 and outer carbon coating layer. Their stable cycle performance owning to the co-effect of Li4 Ti5 O12 as the structural stabilizer and carbon layer as the volume change buffer for preventing the volume change caused by M during cycling. This work provides an effective way to improve the discharge capacity of Li4 Ti5 O12 -based anodes.