MXene-carbon nanotubes-Cellulose-LiFePO4 based self-supporting cathode with ultrahigh-area-capacity for lithium-ion batteries

Abstract

Designing cathodes with more electroactive materials is a promising way to improve the energy density of batteries while it is highly challenging due to their low electronic/ionic transport, poor structural integrity, and irreversible Li+ consumption in full-cell configurations. Herein, we demonstrate a self-supporting cathode based on 3 dimensional MXene-Carbon nanotubes-Cellulose-LiFePO4 (3D-MCC-LFP). The 3D-MCC-LFP cathodes demonstrate some distinct advantages over conventional LFP cathode (Con-LFP), including higher LFP loading (120 mg cm−2) and faster electronic/ionic transport (1.587 S cm−1/1.18 × 10−11 cm2 S−1), which result in better electrochemical performance. Such as, the 3D-MCC-LFP10 cathode (LFP loading is 10 mg cm−2) offers a significantly higher capacity of 0.86 mAh cm−2 at 5 C (1 C=170 mA g−1) than Con-LFP10 of 0.05 mAh cm−2, and a higher retaining capacity of 1.45 mAh cm−2 after 500 cycles at 1 C than Con-LFP10 (1.16 mAh cm−2). Meanwhile, the 3D-MCC-LFP120 cathode demonstrates an ultrahigh areal capacity of 19.2 mAh cm−2. Furthermore, the assembled 3D-MCC-LFP60/SnO2 full-cell demonstrates a high areal capacity of 6.3 mAh cm−2 at 1.6 mA cm−2. Considering its traits of ultrahigh area capacity, excellent electronic/ionic transport and self-supporting characteristics, the 3D-MCC-LFP cathode combined with SnO2 anode is surely promising for high performance lithium-ion batteries.