Maheswari Nallappan, Muralidharan Gopalan
Department of Physics, Gandhigram Rurual Institute- deemed University, Gandhigram, Tamilnadu, India.
Dalton Trans. 2016 Sep 28;45(36):14352-62. doi: 10.1039/c6dt03032g. Epub 2016 Aug 19.
Cerium oxide (CeO2) has emerged as a new and promising pseudocapacitive material due to its prominent valance states and extensive applications in various fields. In the present study, hexagonal CeO2 nanostructures have been prepared via the hydrothermal method employing cationic surfactant cetyl trimethyl ammonium bromide (CTAB). CTAB ensures a slow rate of hydrolysis to form small sized CeO2 nanostructures. The role of calcination temperature on the morphological, structural, electrochemical properties and cyclic stability has been assessed for supercapacitor applications. The mesoscopic hexagonal architecture endows the CeO2 with not only a higher specific capacity, but also with an excellent rate capability and cyclability. When the charge/discharge current density is increased from 2 to 10 A g(-1) the reversible charge capacity decreased from 927 F g(-1) to 475 F g(-1) while 100% capacity retention at a high current density of 20 A g(-1) even after 1500 cycles could be achieved. Furthermore, the asymmetric supercapacitor based on CeO2 exhibited a significantly higher energy density of 45.6 W h kg(-1) at a power density of 187.5 W kg(-1) with good cyclic stability. The electrochemical richness of the CeO2 nanostructure makes it a suitable electrode material for supercapacitor applications.
氧化铈（CeO₂）因其显著的价态和在各个领域的广泛应用，已成为一种新型且有前景的赝电容材料。在本研究中，采用阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）通过水热法制备了六方氧化铈纳米结构。CTAB确保了缓慢的水解速率，从而形成小尺寸的氧化铈纳米结构。针对超级电容器应用，评估了煅烧温度对其形态、结构、电化学性能和循环稳定性的影响。介观六方结构不仅赋予氧化铈更高的比电容，还赋予其优异的倍率性能和循环性能。当充放电电流密度从2 A g⁻¹增加到10 A g⁻¹时，可逆电荷容量从927 F g⁻¹降至475 F g⁻¹，而即使在1500次循环后，在20 A g⁻¹的高电流密度下仍可实现100%的容量保持率。此外，基于氧化铈的不对称超级电容器在功率密度为187.5 W kg⁻¹时表现出高达45.6 W h kg⁻¹的显著更高的能量密度，且具有良好的循环稳定性。氧化铈纳米结构的电化学丰富性使其成为超级电容器应用的合适电极材料。
