Pressure-Induced\nMolding of Black Phosphorus@Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> Composite Electrode and Its Implications on the\nLithium Storage

For the first time, an innovative pressure quenching\ntechnique is used to create the integrated electrode of the black\nphosphorus (BP) @Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> composite material, doing away with the requirement for adhesive\nadditives and simplifying time-consuming processes. Through the formation\nof Ti–O–P bonds with BP, Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXenes can function as conductive\nadditives and affect the interlayer gap. Additionally, we have found\nthat there is a critical synthetic pressure threshold (300 kN) at\nwhich the performance of BP@Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub>-integrated electrodes can be improved: too high\nof a pressure prevents lithium-ion transport because of mesopore reduction;\ntoo low of a pressure prevents Ti–O–P chemical bond\nformation between the two components; and suboptimal pressure does\nnot allow for density enhancement for better electron conduction.\nThe integrated electrode produced at 300 kN shows a discharge capacity\nof about 724.9 mA h/g at 0.1 A/g current density after 100 cycles,\nwhich is much larger than that obtained at 50 kN (270.2 mA h/g). Furthermore,\nthe capacity can remain steady at 560.74 mA h/g even after 500 lengthy\ncycles at the high current density of 0.5 A/g. Significantly lower\nresistance (1.10 × 10<sup>2</sup> Ω at 300 kN; 2.02 ×\n10<sup>3</sup> Ω at 50 kN) and faster reaction kinetics are\nresponsible for this improvement. This study offers a new, straightforward,\nand broadly useful technique for creating integrated electrodes and\nBP-based composite materials.