Roselle-Like Zn2Ti3O8/rGO Nanocomposite as Anode for Lithium Ion Capacitor

Abstract To satisfy the sharp increasing demands of consumer and portable electronic devices, lithium ion capacitors (LICs) are required to provide higher energy and power densities. In view of this, herein, we report a feasible and controllable method to prepare uniform Roselle-like Zn2Ti3O8/reduced graphene oxide (ZTO/rGO) nanocomposite for application as anode of LIC. The results indicate that a compact interface is formed between ZTO and rGO through O(ZTO) − C(rGO) bonds, which can significantly enhance electron transport kinetics. As expected, the ZTO/rGO nanocomposite displays a high reversible specific capacity of 560 mAh g−1 at 0.1 A g−1 and 300 mAh g−1 at 2.0 A g−1 with superior rate capability. More remarkably, for the first time, the ZTO/rGO nanocomposite-based LIC is designed and fabricated, which delivers a high energy density of 204 Wh kg−1 at a power density of 112.5 W kg−1, and ultrahigh power density of 67500 W kg−1 with an energy density of 54.6 Wh kg−1. Moreover, the device can retain 76% of the capacity after 1000 cycles at 1.0 A g−1. The ZTO/rGO-based LIC is expected to be an alternative energy storage device in the future.