高熵(Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2))O纳米粉体的简易制备及超电容性能

Facile Synthesis of High-Entropy(Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2))O Nanopowder and Its Electrochemical Properties As Supercapacitor Electrode

高熵氧化物是一种由高构型熵稳定的新型材料,有望具有独特的电化学性能。采用聚丙烯酰胺凝胶法制备了(Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2))O纳米粉体并研究了其超级电容性能。结果表明:单相(Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2))O纳米粉体的制备温度随着丙烯酰胺/金属阳离子摩尔比的增加而降低。当丙烯酰胺/金属阳离子摩尔比为120:1时,在900℃煅烧2 h所制备的岩盐相高熵纳米粉体呈现出球形形态,粒径为40~65 nm。该高熵纳米粉体在1 A/g的电流密度下具有402 F/g的比电容;当电流密度增大到20 A/g时,仍然能保持62%的初始比电容;在电流密度为5 A/g时,经过2 000次充放电循环后,电容保持率为61%,该研究表明高熵(Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2))O纳米粉体在超级电容器电极材料领域具有良好的应用前景。

High-entropy oxides(HEO) are a novel material with the unique electrochemical properties, which are stabilized due to the high configurational entropy. In this paper, a high-entropy(Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2))O nanopowder with the sizes of 40-65 nm and a rocksalt structure was synthesized by a polyacrylamide gel method and subsequent calcination at 900 ℃ for 2 h in the presence of a mole ratio of acrylamide/metal cations of 120:1. The results show that the temperature of forming a single-phase(Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2))O nanopowder decreases with the increase of the mole ratio of acrylamide/metal cations. The HEO nanopowder has a specific capacitance of 402 F/g at a current density of 1 A/g. A rate capability of 62% appears at 20 A/g. The capacitance retention is 61% after 2 000 cycles at a current density of 5 A/g. It is indicted that(Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2))O nanopowder could be used as a prospective electrode material for supercapacitors.