Li Yuzhu, Lan Qing, Gao Yuanfei, Zhang Dan, Liu Guangyin, Cheng Jinbing
College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061, China.
Henan International Joint Laboratory of MXene Materials Microstructure, College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China.
Molecules. 2024 Sep 23;29(18):4507. doi: 10.3390/molecules29184507.
Anatase titanium dioxide (TiO) has emerged as a potential anode material for sodium-ion hybrid capacitors (SICs) in terms of its nontoxicity, high structure stability and cost-effectiveness. However, its inherent poor electrical conductivity and limited reversible capacity greatly hinder its practical application. Here, ultrathin TiO nanoplates were synthesized utilizing a hydrothermal technique. The electrochemical kinetics and reversible capacity were significantly improved through sulfur and nitrogen co-doping combined with carbon coating (SN-TiO/C). Sulfur and nitrogen co-doping generated oxygen vacancies and introduced additional active sites within TiO, facilitating accelerated Na-ion diffusion and enhancing its reversible capacity. Furthermore, carbon coating provided stable support for electron transfer in SN-TiO/C during repeated cycling. This synergistic strategy of sulfur and nitrogen co-doping with carbon coating for TiO led to a remarkable capacity of 335.3 mAh g at 0.1 A g, exceptional rate property of 148.3 mAh g at 15 A g and a robust cycling capacity. Thus, the SN-TiO/C//AC SIC delivered an impressive energy density of 177.9 W h kg. This work proposes an idea for the enhancement of reaction kinetics for energy storage materials through a synergistic strategy.
锐钛矿型二氧化钛（TiO₂）因其无毒、结构稳定性高和成本效益好，已成为钠离子混合电容器（SIC）潜在的负极材料。然而，其固有的低电导率和有限的可逆容量极大地阻碍了其实际应用。在此，采用水热法合成了超薄TiO₂纳米片。通过硫氮共掺杂结合碳包覆（SN-TiO₂/C）显著改善了其电化学动力学和可逆容量。硫氮共掺杂产生了氧空位，并在TiO₂中引入了额外的活性位点，促进了钠离子扩散加速并提高了其可逆容量。此外，碳包覆为SN-TiO₂/C在反复循环过程中的电子转移提供了稳定支撑。这种TiO₂硫氮共掺杂与碳包覆的协同策略在0.1 A g时实现了335.3 mAh g的显著容量、在15 A g时148.3 mAh g的优异倍率性能以及强大的循环容量。因此，SN-TiO₂/C//AC SIC展现出177.9 W h kg的可观能量密度。这项工作通过协同策略为提高储能材料的反应动力学提出了一种思路。
