(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 以金紅石型TiO2、Li2CO3和Al2O3為原料，采用高溫固相法制備鋰離子電池負(fù)極材料Li4Ti5O12和Li4AlxTi5-xO12(x=0, 0.025, 0.05, 0.1, 0.2, 0.4)。利用X射線衍射儀、掃描電鏡、半電池充放電測(cè)試和交流阻抗測(cè)試研究材料的物相、結(jié)構(gòu)、形貌以及電化學(xué)性能。結(jié)果表明：Al摻雜不會(huì)改變Li4AlxTi5-xO12的尖晶石結(jié)構(gòu)，但會(huì)導(dǎo)致材料顆粒尺寸增大；適當(dāng)Al摻雜后，材料的循環(huán)穩(wěn)定性和極化性能得到改善，充放電比容量和可逆比容量不同程度降低；Li4Al0.025Ti4.975O12具有最優(yōu)的電化學(xué)性能，0.1C倍率下首次充電比容量達(dá)到156.7 mA·h/g。
關(guān)鍵字: 鈦酸鋰；鋰離子電池；負(fù)極材料；Al摻雜
eletrochemical performance of Li4Ti5O12
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Anode materials Li4Ti5O12 and Li4AlxTi5−xO12(x=0, 0.025, 0.05, 0.1, 0.2, 0.4) were prepared by solid-state reaction using rutile TiO2 and Li2CO3 as the reactants. The crystalline structure, morphology, composition and electrochemical properties of the as-prepared materials were characterized by XRD, SEM and half cell charge-discharge testing and AC impedance. The results show that all of the prepared Li4AlxTi5−xO12 keep the structure of spinel, however, the particle size of samples with Al-doping increases in a certain extent and the appropriate amount of Al doping in Li4Ti5O12 leads to obvious decrease in initial and the reversible specific capacity, but improves the cycling stability and electrochemical polarization. In this study, Li4Al0.025Ti4.975O12 shows the best electrochemical performance and delivers the first discharge specific capacity of 156.7mA·h/g at 0.1 C.
Key words: lithium titanate; Li-ion battery; anode material; Al-doping
