Pressure-Induced Molding of Black Phosphorus@Ti3C2Tx Composite Electrode and Its Implications on the Lithium Storage.

ABSTRACT

For the first time, an innovative pressure quenching technique is used to create the integrated electrode of the black phosphorus (BP) @Ti3C2Tx composite material, doing away with the requirement for adhesive additives and simplifying time-consuming processes. Through the formation of Ti-O-P bonds with BP, Ti3C2Tx MXenes can function as conductive additives and affect the interlayer gap. Additionally, we have found that there is a critical synthetic pressure threshold (300 kN) at which the performance of BP@Ti3C2Tx-integrated electrodes can be improved too high of a pressure prevents lithium-ion transport because of mesopore reduction; too low of a pressure prevents Ti-O-P chemical bond formation between the two components; and suboptimal pressure does not allow for density enhancement for better electron conduction. The integrated electrode produced at 300 kN shows a discharge capacity of about 724.9 mA h/g at 0.1 A/g current density after 100 cycles, which is much larger than that obtained at 50 kN (270.2 mA h/g). Furthermore, the capacity can remain steady at 560.74 mA h/g even after 500 lengthy cycles at the high current density of 0.5 A/g. Significantly lower resistance (1.10 × 102 Ω at 300 kN; 2.02 × 103 Ω at 50 kN) and faster reaction kinetics are responsible for this improvement. This study offers a new, straightforward, and broadly useful technique for creating integrated electrodes and BP-based composite materials.