Preparation and electrochemical performance of Li4Ti5O12/carbon/carbonnano-tubes for lithium ion battery

Li4Ti5O12/C/CNTs 鋰離子電池的制備及電化學(xué)性能
a b s t r a c t
A Li4Ti5O12/carbon/carbon nano-tubes (Li4Ti5O12/C/CNTs) composite was synthesized by using a solid-state method. For comparison, a Li4Ti5O12/carbon (Li4Ti5O12/C) composite and a pristine Li4Ti5O12were also synthesized in the present study. The microstructure and morphology of the prepared sam-ples are characterized by XRD and SEM. Electrochemical properties of the samples are eva luated byusing galvanostatic discharge/charge tests and AC impedance spectroscopy. The results reveal that theLi4Ti5O12/C/CNTs composite exhibits the best rate capability and cycling stability among the samples ofLi4Ti5O12, Li4Ti5O12/C and Li4Ti5O12/C/CNTs. At the charge–discharge rate of 0.5 C, 5.0 C and 10.0 C, itsdischarge capacities were 163 mAh/g, 148 mAh/g and 143 mAh/g, respectively. After 100 cycles at 5.0 C,it remained at 146 mAh/g.

摘要

Li4Ti5O12/C/CNTs 復(fù)合材料使用固相反應(yīng)法合成?，F(xiàn)在將Li4Ti5O12/C復(fù)合材料和傳統(tǒng)的Li4Ti5O12 材料做對比研究。用XRD和SEM對樣品的微觀結(jié)構(gòu)和形貌做分析。樣品的電化學(xué)性質(zhì)通過恒流源充放電測試和交流阻抗阻抗譜。結(jié)果表明 Li4Ti5O12/C/CNTs 在Li4Ti5O12 、Li4Ti5O12/C、Li4Ti5O12/C/CNTs中具有最好的比容量和充放電穩(wěn)定性。在0.5℃、5℃和10℃的條件下充放電率分別是163 mAh/g, 148 mAh/g and 143 mAh/g。在5.0℃下充放電循環(huán)一百次，仍能保持148 mAh/g的容量。