Interconnected Metallic Membrane Enabled by MXene Inks Toward High-Rate Anode and High-Voltage Cathode for Li-Ion Batteries

Abstract

The ever-increasing popularity of smart electronics demands advanced Li-ion batteries capable of charging faster and storing more energy, which in turn stimulates the innovation of electrode additives. Developing single-phase conductive networks featuring excellent mechanical strength/integrity coupled with efficient electron transport and durability at high-voltage operation should maximize the rate capability and energy density, however, this has proven to be quite challenging. Herein, it is shown that a 2D titanium carbide (known as MXene) metallic membrane can be used as single-phase interconnected conductive binder for commercial Li-ion battery anode (i.e., Li4Ti5O12) and high-voltage cathodes (i.e., Ni0.8Mn0.1Co0.1O2). Electrodes are fabricated directly by slurry-casting of MXene aqueous inks composited with active materials without any other additives or solvents. The interconnected metallic MXene membrane ensures fast charge transport and provides good durability, demonstrating excellent rate performance in the Li//Li4Ti5O12 cell (90 mAh g−1 at 45 C) and high reversible capacity (154 mAh g−1 at 0.2 C/0.5 C) in Li//Ni0.8Mn0.1Co0.1O2 cell coupled with high-voltage operation (4.3 V vs Li/Li+). The LTO//NMC full cell demonstrates promising cycling stability, maintaining capacity retention of 101.4% after 200 cycles at 4.25 V (vs Li/Li+) operation. This work provides insights into the rational design of binder-free electrodes toward acceptable cyclability and high-power density Li-ion batteries.