Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, People's Republic of China.
ACS Nano. 2011 Jul 26;5(7):5463-71. doi: 10.1021/nn2006249. Epub 2011 Jun 28.
One great challenge in the development of lithium ion batteries is to simultaneously achieve high power and large energy capacity at fast charge and discharge rates for several minutes to seconds. Here we show that nitrogen- or boron-doped graphene can be used as a promising anode for high-power and high-energy lithium ion batteries under high-rate charge and discharge conditions. The doped graphene shows a high reversible capacity of >1040 mAh g(-1) at a low rate of 50 mA g(-1). More importantly, it can be quickly charged and discharged in a very short time of 1 h to several tens of seconds together with high-rate capability and excellent long-term cyclability. For example, a very high capacity of ∼199 and 235 mAh g(-1) was obtained for the N-doped graphene and B-doped graphene at 25 A g(-1) (about 30 s to full charge). We believe that the unique two-dimensional structure, disordered surface morphology, heteroatomic defects, better electrode/electrolyte wettability, increased intersheet distance, improved electrical conductivity, and thermal stability of the doped graphene are beneficial to rapid surface Li(+) absorption and ultrafast Li(+) diffusion and electron transport, and thus make the doped materials superior to those of pristine chemically derived graphene and other carbonaceous materials.
锂离子电池发展的一个巨大挑战是，在几分钟到几秒钟的快速充放电速率下，同时实现高功率和大容量的能量。在这里，我们展示了氮掺杂或硼掺杂的石墨烯可用作高功率和高能量锂离子电池在高倍率充放电条件下的有前途的阳极。掺杂石墨烯在低电流 50mA/g 的情况下具有>1040mAh/g 的高可逆容量。更重要的是，它可以在非常短的时间内（1 小时到几十秒）快速充电和放电，同时具有高倍率性能和出色的长期循环稳定性。例如，在 25A/g（约 30 秒充满电）的条件下，N 掺杂石墨烯和 B 掺杂石墨烯分别获得了约 199 和 235mAh/g 的非常高的容量。我们相信，掺杂石墨烯的独特二维结构、无序表面形态、杂原子缺陷、更好的电极/电解质润湿性、层间距离增加、导电性提高和热稳定性有利于快速表面 Li(+)吸收和超快 Li(+)扩散和电子输运，从而使掺杂材料优于原始化学衍生石墨烯和其他碳质材料。
