(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: 分別以單質(zhì)Cu粉和CuCO3•Cu(OH)2為Cu源，采用固相燒結(jié)法制備鋰離子電池Sn-Co-Cu/C復(fù)合材料，利用SEM、XRD和電池程控測(cè)試儀研究Cu對(duì)材料結(jié)構(gòu)和電化學(xué)性能的影響。結(jié)果表明：Sn-Co/C復(fù)合材料由CoSn相和微量CoSn2組成，添加Cu粉或CuCO3•Cu(OH)2的Sn-Co-Cu/C均由大量CoSn、α-Co3Sn2和少量CoSn2組成；添加的Cu固溶于Sn-Co合金，使顆粒細(xì)化，同時(shí)比表面積也增大。添加Cu粉和CuCO3•Cu(OH)2的Sn-Co- Cu/C的首次充電、放電容量分別為467、319 mA•h/g和489、326 mA•h/g，經(jīng)過(guò)40次循環(huán)后容量保持率分別為83.4%和86.8%；添加Cu導(dǎo)致多相的形成以及顆粒的細(xì)化，增加了Li+的擴(kuò)散通道和增強(qiáng)了材料的結(jié)構(gòu)穩(wěn)定性，從而顯著改善了材料的電化學(xué)性能。
關(guān)鍵字: 鋰離子電池；SnCoC；Cu；固相燒結(jié)；電化學(xué)性能
（College of Materials Science and Engineering, Liaoning Technical University, Fuxin 123000, China）
Abstract:The Sn-Co-Cu/C composites as novel anode material for lithium-ion battery were synthesized using Cu powder and CuCO3•Cu(OH)2 as Cu resource by solid-state sintering, respectively. The influences of Cu on the structures and electrochemical properties of the composites were analyzed by XRD, SEM and charge-discharge measurement. The results show that Sn-Co/C consists of CoSn2 and minor phase CoSn2, and Sn-Co-Cu/C is composed of CoSn, α-Co3Sn2 and a little CoSn2 phase. Cu atoms dissolving in Sn-Co alloy lead to the refinement of grains or particles and the increase of specific surface area. The initial charge and discharge capacity of Sn-Co-Cu/C synthesized from Cu element powders and CuCO3•Cu(OH)2 are 467, 319 mA•h/g and 489, 326 mA•h/g, respectively. After 40 cycles, the capacity retentions of them are 83.4% and 86.8%, respectively. The formation of multiphase and refinement of particles caused by adding Cu is beneficial for accelerating the diffusion velocity of Li ion and enhancing the stability of structure. So, the electrochemical properties are improved significantly.
Key words: lithium-ion batteries; SnCoC; Cu; solid-state sintering; electrochemical properties
