以氧化钇为Y^3+的掺杂源,以蔗糖或导电炭黑为碳源,对Li4Ti5O12同时进行离子掺杂和碳掺杂,采用高温固相法合成负极复合材料Li(4-x/3)YxTi(5-2x/3)O12/C(x=0.1)。重点考察了Y掺杂、Y和碳协同掺杂,以及不同碳源对该复合材料形貌、粒径和电化学性能的影响。结果表明:使用蔗糖为碳源合成的复合材料Li(4-x/3)YxTi(5-2x/3)O12(x=0.1)体现了相对较好的倍率性能和循环稳定性,在0.15C、0.40C、0.70C、1.40C和3.30C下材料首次放电比容量分别为150.4、144.5、144.5、140.8和116.9mAh/g,3.3C下循环10次后容量仍保持为116。7mAh/g。电化学交流阻抗表明,使用蔗糖为碳源合成的复合材料Li(4-x/3)YxTi(5-2x/3)O12的阻抗从纯Li4Ti5O12的912.5Ω降低到227.7Ω。
Li(4-x/3)YxTi(5-2x/3)O12(x= 0.1)as the negative materials for lithium ion batteries was synthesized through a simple solid state reaction in an inert atmosphere using yttria as Y^3+ dopant source and sucrose or conductive carbon black as carbon source. The effects of Y^3+ doping, Y^3+ and carbon doped simultaneously, and different carbon sources such as sucrose or conductive carbon black on the morphology, particle size, electrochemical and performance of anode materials were investigated. It shows that Li(4-x-/3)YxTi(5-2x/3)O12(x= 0.1) composites using yttria as Y^3+dopant source and sucrose as carbon source exhibits a relatively good rate capability and cycling stability. At the charge-discharge rate of 0.15 C, 0.4 C, 0.7 C, 1.4 Cand 3.3 C, its discharge specific capacities were 150.4, 144.5, 144.5, 140.8 mAh/g and 116.9 mAh/g, respectively. After 10 cycles at 3.3 C, its discharge specific capacity remained at 116.7 mAh/g. The impedance Pa of this material is 227.7 Ω, while that of the undoped Li4Ti5O12matedal is 912.5 Ω,