稳定化锂粉/石墨复合负极的合成与性能表征

Synthesis and electrochemical characterization of stabilized Li/GO composite anode

采用高分散锂粉与石墨制备了具备高比容量和高稳定性能的复合负极材料。该锂粉/石墨复合负极与锰酸锂正极组装的全电池经过600次循环后,锰酸锂的比容量依旧保持93.1 mAh/g,循环效率接近100%。复合负极组装的对称电池经过500 h循环后,过电势仍低于10 mV。制备的锂粉/石墨复合负极不仅可以有效缓解金属锂电极的体积膨胀效应,还可以明显抑制锂枝晶的生长,长时间循环后的锂粉/石墨复合负极表面枝晶数量明显少于纯锂负极。

The composite anode materials with high specific capacity and high stability were prepared by using highly dispersed lithium powder and graphite. The full cells using the lithium powder/graphite(Li/GO) electrode and LiMn2O4 electrode exhibits excellent cycle stability. The discharge specific capacity of 93.1 mAh/g and an average coulombic efficiency of 100%are achieved for more than 600 cycles. The symmetric lithium cells of the composite anode exhibit small Li plating/stripping overpotential (10 mV) at a high current density of 3 mA/cm2 over 500 hours. The Li/GO anode can not only effectively alleviate the volume expansion effect of the lithium electrode, but also obviously inhibit the growth of the lithium dendrite. The number of dendrites on the surface of the Li/GO anode is obviously less than that of the pure lithiumanode after a long time cycle.