posted on 2020-10-12, 18:37authored byTianyu Zhu, Yan Wang, Yang Li, Rui Cai, Jianfang Zhang, Cuiping Yu, Jingjie Wu, Jiewu Cui, Yong Zhang, Pulickel M. Ajayan, Yucheng Wu
Lithium-ion
capacitor (LIC) is an efficient hybrid electrochemical
energy storage device, which dominates high power and energy density
simultaneously. In this work, a method of liquid phase fragmentation
combined with solvothermal and freeze drying treatment is used to
fabricate CoO quantum dots/reduced graphene oxide composite (CoO QDs/rGO)
anode. Liquid phase fragmentation plays an important role in the controllable
formation of ultrafine CoO nanoparticles and their uniform anchoring
on three-dimensional (3D) rGO aerogels. The CoO/rGO anode exhibits
an initial discharge specific capacity of 1233.6 mA h g–1 and a discharge specific capacity of 726.1 mA h g–1 after 700 cycles at 1.0 A g–1. The high specific
capacity and good cycle performance are attributed to the CoO QDs
with short ion transport paths, low stress change, and large interaction
area between the electrode and electrolyte as well as a flexible conductive
rGO with a large active surface area and abundant active sites. Metal
oxide quantum dots formed by liquid phase fragmentation and the corresponding
3D multichannel metal oxide/rGO composite aerogels could be developed
as superior candidates for efficient energy storage in LIC.