正极集流体为碳纳米管宏观膜的锂离子电池及其性能

Performance of lithium ion batteries using a carbon nanotube film as a cathode current collector

采用超轻的碳纳米管(Carbon nanotubes,CNTs)宏观膜替代传统的金属铝集流体,替换后的锂离子电池以LiCoO2为活性物质,在1 C条件下电池首次放电比容量为132.8mAh·g-1,500次循环后容量保持率高于80%;当正极材料层面密度为16mg·cm-2时,LiCoO2-CNT电极的能量密度比LiCoO2-Al电极提高25%;同时,CNTs膜作为正极集流体的电池自放电率低于1.5%。该CNTs膜经电流刺激后仍保持较高的石墨化程度,相比金属集流体,其表面束状的多孔结构可有效保证正极材料层和集流体间的紧密接触。该膜有望替代传统铝箔成为新一代锂离子电池用集流体。

A carbon nanotube （CNT） film was used as the current collector and LiCoO2 as the cathode for a lithium ion battery. The battery showed a high initial discharge capacity of 132. 8 mAh·g-1 , a high retention rate of over 80% after 500 cycles under 1C and a low self-discharge rate of 1. 5% . When the areal density of the CNT film is 16 mg·cm-2 , the energy density of the LiCoO2-CNT battery is 25% larger than that of a LiCoO2-Al battery. The superior properties of the battery may be attributed to the high electrochemical stability of the graphitic structure of CNTs and the porous surface of the CNT film that ensures a high contact surface area between the current collector and the cathode material. The CNT film is promising as a new current collector for lithium ion bat-teries. Macroscopical carbon nanotubes （CNTs） was studied as current collector for lithium ion battery. LiCoO2 was used as active substance. The prepared battery showed high first special discharge capacity （132. 8mAh·g-1 ） and retention rate （over 80% ） after 500 cycles under 1C. When the areal density of cathode layer is 16mg cm-2 , energy density of LiCoO2-CNT battery is 25% larger than that of LiCoO 2-Al battery. Meanwhile, the battery with CNTs film as current collector has low self-discharge rate （1. 5% ）. The superior properties of the battery maybe attribute to graphite structure even underwent current and porous surface of the CNTs film. The characteristic of the surface ensures the cathode to contact with CNTs film tightly. Considering the stable and outstanding properties , the CNTs film is expected to be a new current collector for lithium ion battery.