Dealloyed nickel skeleton hosting in-situ formed multimetallic phosphides for enhanced electrochemical energy storage

Abstract

Transition metal phosphides (TMPs) exhibit considerable potential in supercapacitors (SCs) electrodes fabrication due to their high power densities and conducive ion transport, positioning them as quintessential candidates for such application. Despite their promise, monometallic phosphides require further electrochemical performance enhancements. This work unveils an innovative strategy for synthesizing complex cobalt/nickel phosphides directly on a nickel skeleton (Ni@NCP), achieved by the selectively leaching copper from a Ni–Cu alloy via a dealloying process after electrodeposition, significantly improving electrochemical performance through increased electroactive sites and optimized ion diffusion channels. The Ni@NCP electrode exhibits an impressive specific capacitance of 612 F g−1 at a high current density of 20 A g−1. Furthermore, the unique hollow nanotube structure greatly enhances cyclic stability, maintaining 80.1 % capacity after 10,000 cycles at 10 A g−1. This research presents a methodical approach to electrode material synthesis, emphasizing the construction of supportive frameworks and active sites, thereby underscoring the substantial potential for advancements in SC electrode technology.