【摘要】 研究了用简单混杂和球磨方法制备的天然石墨／锑复合材料作为锂离子电池负极材料的嵌／放锂性能以及循环过程中嵌／放锂容量衰减机理。复合材料中的锑以独立的可逆嵌／放锂反应参与吸／放锂过程并显著提高复合材料的嵌／放锂容量。较大颗粒的锑在嵌／放锂过程中体积剧变导致颗粒破碎、电接触恶化而渐渐失去嵌／放锂活性,因此由简单混杂所获得石墨／锑复合材料在循环过程中容量逐渐降低；采用球磨方法在天然石墨颗粒表面形成弥散分布的小颗粒锑则能获得具有较高可逆容量和较好的循环稳定性的石墨／锑复合锂离子电池负极材料。更多还原

【Abstract】 The natural graphite-antimony composite were prepared by simply mixing antimony powder with natural graphite or bali-milling the mixture of antimony powder with natural graphite. The Li insertion/extraction properties as anode materials for lithium-ion batteries and the mechanism of capacity fade of the composites were studied. Antimony takes part in Li~+ insertion/extraction process of composites by individual reversible Li insertion/extraction reactions, and remarkably increases the Li insertion/extraction capacity of the composites. But the antimony particles of larger size in the simply mixed composite gradually lost their Li insertion/extraction ability because of the fragmentation of the particles and the deterioration of electric contact between the particles resulted from the large volume changes of the antimony particles during Li insertion/extraction cycling processes, the capacity of the simply mixed composite gradually declined. By ball-milling method, small particles of antimony dispersed on the surfaces of natural graphite particles are obtained and the graphite/antimony composite show higher reversible capacity and better cycling stability as anode materials for lithium-ion batteries. The electrode materials reach 393/345 mAh/g of Li insertion/extraction capacity during the second insertion/extraction process and 391/360 mAh/g of Li insertion/extraction capacity during the 37th Li insertion/extraction process respectively, the antimony in the composite attains 78％ of their theroetical Li insertion/extraction capacity.更多还原