纳米多孔CuMn基氧化物电极的制备及性能

Preparation and properties of nano porous CuMn-based oxide electrodes

铜氧化物由于具有理论容量高和储量丰富等优势成为下一代有前景的超级电容器电极材料,但其电子导电性低和长期循环稳定性差制约实际应用。本文以三明治型Cu_(30)Mn_(70)/Cu/Cu_(30)Mn_(70)箔带为母合金,通过脱合金与自蔓延氧化相结合的技术制备了高导电柔性纳米多孔CuMn@多组元氧化物核-壳复合电极,并探究了不同脱合金条件下Mn残余量对电极形貌、结构和电化学性能的影响。实验结果表明,随着腐蚀时间的延长,Mn的残余量会逐渐变少,而不同腐蚀条件下获得的多组元氧化物均由CuO、Cu_(2)O、Cu_(x)Mn_(1-x)O和CuMn_(2)O_(4)相组成。腐蚀时间为50min时制备的电极(NP-TMO5)在三电极体系测试中具有最优的电化学性能:5mA/cm^(2)电流密度下,面积比电容为1045.7mF/cm^(2),且循环12000次后,电容保持率为95.9%。两电极对称体系测试中,3mA/cm^(2)下,面积比电容为419.83mF/cm^(2),能量密度为0.084mWh/cm^(2)。即使在100mV/s的扫描速率下循环10000次,比电容保持率仍为97.9%。样品优异的性能得益于多孔电极的核-壳结构和多组元氧化物间的协同作用对电子结构的优化和体积膨胀的缓冲,为高负载复合多孔结构的设计提供理论依据。

With the merits of high theoretical specific capacitance and abundant reserves,copper oxides have become next-generation electrode materials for supercapacitors,but their applications are still limited to the poor electron conductivity and inferior cyclic stability.In this work,the sandwich-like Cu_(30)Mn_(70)/Cu/Cu_(30)Mn_(70) foil was used as mother-alloy.A highly conductive and flexible nano-porous Cu Mncore and multicomponent oxide-shell electrode with different Mn residues was prepared by the combination of dealloying and self-propagating oxidation.The effect of Mn residues on the morphology,structure and electrochemical properties of the electrode under different dealloying conditions was investigated.The experimental results showed that the residual amount of Mn would gradually decrease along with extension of corrosion time.The multicomponent oxides obtained under different corrosion conditions were composed of CuO,Cu_(2)O,Cu_(x)Mn_(1-x)O and CuMn_(2)O_(4) phases.In three electrode system,the NP-TMO5 sample indicated the highest area capacitance of 1045.7mF/cm^(2) at current density of 5mA/cm^(2) and maintained 97.9%capacitance after 12000 cycles.The symmetric device composed by NP-TMO5 delivered high area capacitance and energy density of 419.83mF/cm^(2) and 0.084mWh/cm^(2) at current density of 3mA/cm^(2),respectively.Even after 10000 cycles at a scanning rate of 100mV/s,the specific capacitance retention was still 97.9%.The excellent performance of the sample was attributed to the coreshell structure of the porous electrode and the synergistic effect between multi-component oxides,which can optimize the electronic structure and buffer the volume expansion,providing a theoretical basis for the design of highly loaded composite porous structures.