等离子体表面处理法改进锂离子电池碳负极性能

Improvement of the properties of natural graphite negative electrode for Li-ion batteries by plasma surface treatment

锂离子电池中,由于与电解液之间浸润性不好,天然石墨负极的实际利用率偏低。本文尝试采用等离子体表面处理的方法改进负极活性物质的利用率,以提高负极有效放电容量。实验结果证实,在氧气和甲基丙烯酸(MMA)气氛中对负极极片表面等离子体处理可以有效提高其放电容量。未处理的负极极片放电容量为320.9mAh/g,在氧气中等离子体处理后负极极片放电容量略有改进,为327.9mAh/g,在甲基丙烯酸(MMA)气氛中等离子体处理可明显提高负极极片容量,达到352.7mAh/g。认为表面等离子体处理改变了负极极片表面极性,使其与锂离子电池电解液的浸润性得到改善。

Due to the poor wettability, in the commercial Li-ion batteries, the effective utilization of the natural graphite negative electrode is relatively low. In the present work, we try to improve the performance of nalural graphite negative electrode by plasma treatment of the electrode sur- face, to improve the effective discharge capacity. Experiment results have evidenced that plasma treatment in oxygen and methyl methalacrylate （MMA） atmospheres can effectively increase the discharge capacity from 320.9 to 327.9 for oxygen and to 352.7 mAh/g for MMA. The benefit effect of plasma treatment should be attributed to the improved wettability between non-polar surface of solid electrode and polar electrolyte by introducing polarizable surface functional groups into the solid electrode surface.