Abstract：
The pseudocapacitive properties of CeO2 are largely dependent on its surface Faradaic redox reaction kinetics; however, its electrochemical performance is still limited by the low utilization due to the inefficient diffusionfreeways and the limited active sites. Herein, we prepare a 0D/3D composite composed of oxygen-deficient CeO2 quantum dots (0D) anchored on a 3D hollow porous N-doped carbon framework (CeO2-x QD@PHC) via a facile template-confined strategy followed by a chemical co-precipitation. The refined QDs and hollow structure greatly shorten the ion diffusion paths and lower the internal strain during cycling. The integration of CeO2-x QDs with PHC structure endows enriched accessible active sites and enhances the electrical properties. As a result, the optimized CeO2-x QD@PHC exhibits an improved specific capacitance and good rate performance in comparison to those of the CeO2-x-free PHC. Moreover, a symmetric supercapacitor with CeO2-x QD@PHC as an electrode is constructed, delivering a high energy density of 3.874 Wh kg-1 at a power density of 149.98 W kg-1.
摘要：
CeO2的准电容特性在很大程度上取决于其表面法拉第氧化还原反应动力学；然而，由于低效的扩散高速公路和有限的活性位点，其电化学性能仍然受到低利用率的限制。在这里，我们通过简单的模板约束策略，然后进行化学共沉淀，制备了由缺氧CeO2量子点（0D）锚定在3D中空多孔N掺杂碳框架（CeO2-xQD@PHC）上的0D/3D复合材料。精细的QD和中空结构大大缩短了离子扩散路径，并降低了循环过程中的内部应变。具有PHC结构的CeO2-x量子点的集成赋予了丰富的可访问活性位点并增强了电性能。因此,与不含CeO2-x的PHC相比，优化的CeO2-xQD@PHC表现出改善的比电容和良好的倍率性能。此外，构建了以CeO2-xQD@PHC为电极的对称超级电容器，在149.98Wkg-1的功率密度下提供3.874Whkg-1的高能量密度。
