Phytic Acid Assisted Fabrication of High Specific Surface Area Carbon-Wrapped Ni₂P₄O₁₂ Nanoparticle Electrodes for Lithium-Ion Battery

Abstract

Transition metal tetrametaphosphates (M2P4O12) are a novel electrode material for lithium-ion batteries (LIBs) due to their good electrical conductivity and reversible redox behavior. In this work, carbon layer self-encapsulated Ni2P4O12 nanoparticles were prepared by facile oil bath evaporation and high temperature calcination. A detailed investigation of the synthesis mechanism was performed through controlled variables. Among the various synthesis factors, the glucose introduction generates a self-coated carbon layer; the calcination temperature can directly affect the crystalline phase formation; the product was calcined at 800° equipped with the optimal lithium storage performance; the selection of organic phytic acid was correlated with the Ni2P4O12 micromorphology; and the dosage of phytic acid, while having an insignificant effect on the crystalline phase, strongly associated with lithium-ion storage. 4 mL of the phytic acid-synthesized Ni2P4O12 material showed the best lithium storage performance. On this basis, the fabricated NPO-PA-GL electrode materials were applied in LIBs, and electrochemical tests were conducted. Benefiting from the modulated electronic structure of the carbon layer, high specific surface area, and nanoparticle structure, the NPO-PA-GL electrode exhibited high-efficiency electrochemical activity. Particularly, the cell capacity amounted to 871.8 mA h g–1 at a current density of 50 mA g–1. After 500 constant-current charge/discharge cycles at 1 A g–1, the capacity increased by 128.4%. This work not only indicated that NPO-PA-GL would be a prospective LIB anode material but also pointed out a new direction for the exploitation of LIB anode materials, which will lead to significant innovations in sustainable chemistry and engineering.