三维石墨烯/泡沫镍基底上制备Ni掺杂Co(OH)_2复合材料及其超电容性能

Preparation of Ni-doped Co(OH)_2 composite on three-dimensional graphene/nickel-foam network and its super-capacitive performance

以化学气相沉积法制备的三维网状石墨烯/泡沫镍(3DGE/NF)为基底,电化学沉积Ni掺杂Co(OH)2纳米片得到三维镍钴双氢氧化物/石墨烯/泡沫镍(3D NixCo1-x(OH)2/GE/NF)复合电极材料,研究Ni掺杂量对材料的形貌及电化学性能的影响.结果表明:在Co(OH)2中掺杂适量的Ni可以改善材料的表面形貌;高质量、高导电性石墨烯的存在促进电极与电解液的电荷传输,加上镍钴的协同作用,能有效提高材料的比容量和循环倍率性能.当Ni掺杂量为34%时,3D Ni0.34Co0.66(OH)2/GE/NF复合电极材料具有最佳的电化学性能,当电流密度为3 A/g时,其在1mol/L的KOH电解液中比容量达到1 714F/g,当电流密度升高到30A/g时比容量仍保持有73%达到1 254F/g,显示出较好的倍率性,且在10A/g的大电流密度下经过500次循环后,比容量保持率为83%.

Ni-doped Co （OH） 2 nanoflakes were electrochemically deposited on 3-D graphene/nickel foam network as substrate, which was synthesized by chemical gas-phase deposition method, so that a compos- ite electrode material named as three-dimensional nicklecobalt double hydroxide-graphene-niekle foam （NixCol-x（OH）2/GE/NF was obtained. The effect of different Ni content on morphology and electro- chemical behavior of obtained 3-D Nix Co1-x （OH）2/GE/NF composite was investigated. The result showed that an appropriate amount of Ni doping in Co（OH）2 could improve the surface morphology. The high-quality and high-conductivity graphone would promote the charge transfer between the electrode and electrolyte. In addition, the cooperative action of nickel and cobalt would make the specific capacity and cycle multiplicity improved effectively. The composite electrode would have optimal electrochemical per- formances when the Ni content was 34%. The 3-D Ni0.a4Co0.66 （OH）2/GE/NFelectrode would have a high spe- cific capacitance of I 714 F · g-1 when the current density was 3 A · g-1 in 1 mol/L KOH electrolyte. It would al- remain a high capacitance of 1 254 F/g as the current density reached up to 30 A/g, displaying a good multiplic- ity. The specific capacitance would remain as 83% after 500 cycles with high current density of 10 A/g.