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采用溶胶-凝胶法合成了Li_4Ti_5O_(12)/Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3复合负极材料,通过X射线衍射、扫描电子显微镜、恒电流充放电、循环伏安和电化学阻抗研究复合材料的结构、形貌及电化学性能。结果表明:溶胶-凝胶法能合成纯相Li_4Ti_5O_(12)/Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3复合负极材料颗粒均匀。与纯相Li_4Ti_5O_(12)相比,引入Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3的Li_4Ti_5O_(12)复合负极材料具有更低的锂离子嵌入/脱出阻抗,Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3质量分数为1%、2%、3%、4%、5%的Li4Ti5O12复合负极材料首次放电容量比纯相Li_4Ti_5O_(12)分别提高了6.2%、11.8%、15.5%、8.0%和2.0%。充放电循环20次后,Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3质量分数为3%的Li_4Ti_5O_(12)复合负极材料循环性能最好,平均每次循环容量衰减率为0.022%。
The Li 4 Ti 5 O 12 / Li 1.3 Al 0.3 Ti 1.7 1.7 PO 4 composite anode materials were synthesized by sol-gel method and characterized by X-ray diffraction, scanning electron microscopy, galvanostatic charge-discharge, cyclic voltammetry And electrochemical impedance spectroscopy of the composite structure, morphology and electrochemical properties. The results show that the particles of pure Li_4Ti_5O_ (12) / Li_ (1.3) Al_ (0.3) Ti_ (1.7) (PO_4) _3 composite can be synthesized uniformly by sol - gel method. Li_4Ti_5O_ (12) composite negative electrode material with Li_ (1.3) Al_ (0.3) Ti_ (1.7) (PO_4) _3 has lower lithium ion insertion / extraction resistance than Li_4Ti_5O_ (12) The first discharge capacity of Li4Ti5O12 composite cathode materials with Al_ (0.3) Ti_ (1.7) (PO_4) _3 mass fractions of 1%, 2%, 3%, 4% and 5% increased by 6.2% than that of pure Li_4Ti_5O_ (12) 11.8%, 15.5%, 8.0% and 2.0%. After 20 cycles of charging and discharging, the Li_4Ti_5O_ (12) composite negative electrode material with Li_ (1.3) Al_ (0.3) Ti_ (1.7) (PO_4) __3 mass fraction had the best cycling performance with an average capacity decay rate of 0.022 %.