单壁碳纳米管导电添加剂对锂离子电池正极材料电化学性能的影响

Effect of single-walled carbon nanotubes as conductive additives on electrochemical performance of cathode materials of lithium-ion batteries

单壁碳纳米管具有极高的长径比和优异的电学与力学性能,在锂离子电池导电添加剂中有着良好的应用前景.针对单壁碳纳米管在电池浆料中分散性差的问题,利用Birch还原烷基化反应对单壁碳纳米管进行可控功能化修饰,制备兼具良好导电性与分散性的碳纳米管材料,并考察其作为导电添加剂对锂离子电池正极材料电化学性能的影响.结果表明,以经过3轮烷基功能化修饰的单壁碳纳米管为导电添加剂时,锂离子电池的循环性能与倍率性能均优于其他样品,在5 C的放电倍率下循环400圈后仍有110 mAh/g的比容量.

Single-walled carbon nanotubes(SWCNT)have a very high aspect ratio and excellent electrical and mechanical properties,exhibiting promising application in conductive additives in lithium-ion batteries.Aiming at elevating the low dispersibility of SWCNT in battery slurry,SWCNT were controllably functional modified by Birch reductive alkylation to prepare carbon nanotubes with good conductivity and dispersion.The influence of modified SWCNT as conductive additives on the electrochemical performance of cathode for lithium-ion batteries was studied.The results showed that the lithium-ion batteries had the best cycle performance and rate capability when the three-round functional modified SWCNT were used as conductive additives.The battery still had a specific capacity of 110 mAh/g after 400 cycles at a discharge rate of 5 C.