Supercapacitor performance and first-principles calculation study of Co-doping Ni(OH)2
Co-doped Ni(OH)2 was prepared by a simple co-precipitation method,and the electrochemical perfor-mance was improved by the Co/Ni synergistic effect.Co-doping refined the grain size of Ni(OH)2,improved the mor-phology of the material,exposed more active sites,and improved the electrochemical activity of the material.Mean-while,the first-principle calculation showed that Co-doping also changed the electron density distribution of Ni,leading to the improvement of the charge transport and ion diffusion properties of the material.Due to the appropri-ate quantity of Co doping,Ni0.84Co0.16(OH)2 had excellent electrochemical energy storage of 1 589.6 F·g-1 at the cur-rent density of 1 A·g-1,far higher than that of Ni(OH)2(1 191.7 F·g-1).Meanwhile,the assembled asymmetric super-capacitor had an energy density of 8.30 Wh·kg-1 when the power density was 21.33 kW·kg-1,showing a good energy storage performance and cycle performance.