Phosphate Species up to 70% Mass Ratio for Enhanced Pseudocapacitive Properties

The emerging phosphate species on the surface or near-surface of electrode materials are versatile and have an intriguing ability for dramatically enhanced electrochemical performance. Unfortunately, the distribution/dispersion of phosphate species still keeps at levels on the exterior not within the interior surface of materials, and the micro-/nanoscale tuning is commonly rarely concerned and its function remains poorly understood. Herein, for the first time, well-dispersed phosphate species up to 70% mass ratio implanted within Ni-doped CoP nanowire matrix are presented via an efficient low-temperature phosphorization strategy. The resultant nanohybrids possess kinetics-favorable open frameworks with abundant mesopores and a high degree covalency in the chemical bonds, thus leading to rapid mass transport/charge transfer and enhanced redox reaction kinetics. Remarkably, the phosphate species feature superwettability toward water and strong affinity for OH- in the electrolyte, evidenced by the shortened distance and reduced adsorption energy between the OH- and the nuclear Co atoms on the nanohybrids as revealed by density functional theory calculations. As such, the nanohybrids exhibit an ultrahigh specific capacity of 250 mAh g(-1) even at 50 A g(-1). This work presents a deeper understanding of the dispersion and role of phosphate species for supercapacitors and other energy-related storage/conversion devices.