摘要
为提升MnO_(2)基材料的结构稳定性,解决Mn^(2+)易溶解和导电性差等问题,以NaH_(2)PO_(2)·H_(2)O为磷源,通过一步水热法在泡沫镍(NF)基底上成功制备了自支撑磷掺杂MnO_(2)电极材料(Px-MnO_(2),x=0.017、0.051和0.085 g,为NaH_(2)PO_(2)·H_(2)O投加量),采用SEM、TEM、XRD和XPS对其形貌结构和组成成分进行了表征,并以Px-MnO_(2)为工作电极,通过三电极体系测试了其电化学性能。结果表明,成功制备了P_(0.017)-MnO_(2)、P_(0.051)-MnO_(2)和P_(0.085)-MnO_(2)电极材料,当扫描速率从5 mV/s增至50 mV/s时,3种电极均具有较好的电化学可逆性。P_(0.051)-MnO_(2)电极放电时间最长(约230 s),其电容性能最佳,这可能与P_(0.051)-MnO_(2)具有较大的比表面积(236.6864 m^(2)/g)和纳米颗粒状的结构有关。在1 A/g的质量电流密度下,P_(0.051)-MnO_(2)电极的质量比电容为353.8 F/g,优于MnO_(2)电极(93.5 F/g)、P0.017-MnO_(2)电极(217.7 F/g)和P_(0.085)-MnO_(2)电极(169.8 F/g)。当质量电流密度为10 A/g时,P_(0.051)-MnO_(2)电极的比电容为267.7 F/g,容量保持率为75.7%,该电极在循环2000圈后,容量保持率仍可达94.3%。在电化学阻抗测试中,P_(0.051)-MnO_(2)电极具有更小的体系欧姆电阻(约0.90Ω)和扩散电阻(约0.20Ω)。当扫描速率为50 mV/s时,P_(0.051)-MnO_(2)电极的电容贡献率为87%,高于MnO_(2)电极的71%。磷掺杂有效增强了MnO_(2)的电荷迁移能力,产生了更多的活性位点,提升了其电容性能。
In order to improve the structural stability of MnO_(2)-based materials and solve the problems of easy dissolution of Mn^(2+)as well as the poor conductivity of MnO_(2),the self-supporting phosphate-doped MnO_(2)electrode materials(Px-MnO_(2),x=0.017,0.051 and 0.085 g,representing the dosage of NaH_(2)PO_(2)·H_(2)O)were successfully prepared on nickel foam(NF)substrate by one-step hydrothermal method using NaH_(2)PO_(2)·H_(2)O as phosphorus source,the morphology,structure and composition were characterized by SEM,TEM,XRD and XPS,and the electrochemical performances were evaluated in a three-electrode system using Px-MnO_(2)as working electrode.The results indicated that P_(0.017)-MnO_(2),P_(0.051)-MnO_(2),and P_(0.085)-MnO_(2),were successfully prepared.When the scan rate increased from 5 mV/s to 50 mV/s,all three electrodes exhibited good electrochemical reversibility.The P_(0.051)-MnO_(2)electrode possessed the longest discharge time(about 230 s)and optimal capacitance performance because of its larger specific surface area(236.6864 m^(2)/g)and nanoparticle structure.At a mass current density of 1 A/g,the mass specific capacitance of P_(0.051)-MnO_(2)electrode was 353.8 F/g,better than those of MnO_(2)electrode(93.5 F/g),P0.017-MnO_(2)electrode(217.7 F/g)and P0.085-MnO_(2)electrode(169.8 F/g).When the mass current density increased to 10 A/g,the specific capacitance of P_(0.051)-MnO_(2)electrode reached 267.7 F/g,while the capacity retention rate was 75.7%,and the capacity retention rate was 94.3%after 2000 cycles.The P_(0.051)-MnO_(2)electrode displayed smaller system ohm resistance(about 0.90Ω)and diffusion resistance(about 0.20Ω)in electrochemical impedance testing.When the scanning rate was 50 mV/s,the capacitance contribution rate of P0.051-MnO_(2)electrode was 87%,higher than that of MnO_(2)electrode(71%).Phosphorus doping effectively enhanced the charge transfer ability of MnO_(2),generated more active sites,and improved its capacitive performance.
作者
邓成鸣
郭石璇
何锶威
张惠玉
伍建华
DENG Chengming;GUO Shixuan;HE Siwei;ZHANG Huiyu;WU Jianhua(College of Physics and Electromechanical Engineering,Jishou University,Jishou 416000,Hunan,China)
出处
《精细化工》
北大核心
2025年第9期1941-1950,2088,共11页
Fine Chemicals
基金
湖南省自然科学基金项目(2020JJ4505)。
关键词
MnO_(2)
磷掺杂
超级电容器
电化学性能
水热法
功能材料
MnO_(2)
phosphorus doping
supercapacitors
electrochemical performances
hydrothermal method
functional materials
