Abstract:

Combining the advantages of Lithium ion battery’s high energy density and electric double layer capacitor’s excellent power performance, Lithium ion capacitor has been regarded as one of the most important research area for supercapacitors. Using high capacitance Li2NiO2 as the Li+ resources for negative electrode, composited activated carbon as the positive electrode, a 300 F lithium ion capacitor has been prepared without “lithium foil” during the pre-doping process. The physical and electrochemical performance of Li2NiO2 and the adding amount of Li2NiO2 have been investigated. The results shows that: Li2NiO2 exhibits a distinctively high irreversible capacity of 398 mA·h·g1 with an irreversible capacity ratio of 94.8% during the first cycle. After adding 15%～20% Li2NiO2 for the lithium ion capacitors, it shows more than 75% rate performance at 10A and nearly 91% capacitance retention during the cycle life time. When adding 20% Li2NiO2 at the composite electrode, the cell has nearly 400F capacitance, 15.5W·h·kg1 energy density and 1.3 kW·kg1 power density. Meantime, the simply making process will prompt this kind of lithium ion capacitor to embracing a bright future.

Key words: lithium ion capacitor, high lithium metal oxide materials, activated carbon, pre-doping , amount