(遼寧工程技術(shù)大學(xué) 材料科學(xué)與工程學(xué)院，阜新 123000)
摘 要: 分別以葡萄糖和乙炔黑為碳源，采用固相燒結(jié)法制備Sn-Co/C鋰離子電池負(fù)極復(fù)合材料，探討碳源種類對材料結(jié)構(gòu)和電化學(xué)性能的影響規(guī)律。結(jié)果表明：摩爾比為1:1的Sn-Co合金由CoSn相和微量CoSn2相組成；在Sn-Co/C復(fù)合材料中，大部分葡萄糖熱解炭和乙炔黑存在于Sn-Co合金顆粒表面，少部分進(jìn)入顆粒內(nèi)部，會在一定程度上阻礙Sn-Co合金的相變反應(yīng)，殘留微量CoSn2和Co3Sn2相，同時(shí)阻礙Sn-Co合金晶粒或顆粒的長大，起到細(xì)化晶粒或顆粒的作用。添加葡萄糖熱解炭和乙炔黑有利于提高Sn-Co/C復(fù)合材料的電子導(dǎo)電和Li+擴(kuò)散，從而提高其電化學(xué)活性；并且添加葡萄糖的Sn-Co/C復(fù)合材料電化學(xué)性能更好，在電流密度為0.05 mA/cm2條件下的首次可逆放電容量為325 mA？h/g，經(jīng)過100次循環(huán)后的容量保持率達(dá)到70.8%，循環(huán)性能比Sn-Co合金的提高26.8%，顯示出良好的結(jié)構(gòu)穩(wěn)定性。
關(guān)鍵字: 鋰離子電池；Sn-Co合金；碳源；電化學(xué)性能
（College of Materials Science and Engineering, Liaoning Technical University, Fuxin 123000, China）
Abstract:The Sn-Co/C composites as anode material for lithium-ion battery were synthesized by solid reaction sintering method using glucose and acetylene black as carbon sources, respectively. The influence of carbon source type on the structures and electrochemical properties of materials was analyzed. The result shows that Sn-Co alloy with Sn and Co mole ratio of 1:1 consists of CoSn phase and minor CoSn2 phase. Most of pyrolytic carbon from glucose and acetylene black exists on the surface of Sn-Co alloy particle, and a few distributes in interior of Sn-Co alloy particle. Therefore, the pyrolytic carbon and acetylene black hinders the transformation reaction of Sn-Co alloy, leading to the residual of a small amount of CoSn2 or Co3Sn2 phase and hindering the growth of grain or particle of Sn-Co alloy at some degree, which refines the grains or particles of Sn-Co alloy. The addition of pyrolytic carbon and acetylene black is beneficial for improving the electronic conductivity and Li+ diffusion in Sn-Co/C composite, and the former is better. The initial discharge capacity of Sn-Co/C composite adding glucose is 325 mA？h/g at a current density of 0.05 mA/cm2, after 100 cycles the capacity retention is above 70.8%, which is 26.8% higher than that of Sn-Co alloy, therefore, the Sn-Co/C composite has good structure stability.
Key words: lithium-ion battery; Sn-Co alloy; carbon source; electrochemical property
