Abstract

Iron-doped potassium titanate with a hollandite structure is synthesized by the solid-phase method. To reduce the contact resistance and to increase the diffusion coefficient of potassium ions, a conductive carbon coating is applied to the surface of the titanate synthesized in an argon atmosphere. The formation of the composite material is confirmed by the results of X-ray phase analysis, scanning electron microscopy, and IR spectroscopy. The half-cells with potassium metal in a CR2025 case, which are assembled on the basis of the synthesized composite, are tested electrochemically with subsequent calculation of the specific capacitance, power density, and energy density. It is found that the specific capacitance of an electrode with a carbon coating is 10–15% higher with low sweep rates (1 and 3 mV s^–1). It is shown that the use of carbon coatings increases the diffusion coefficient of potassium to 1.77 × 10^–14 cm² s^–1/2.

中文翻译：

---

含碳涂层的荷兰石 K1.5Fe1.5Ti6.5O16 的电化学性能

摘要

采用固相法合成了具有荷兰石结构的掺铁钛酸钾。为了降低接触电阻并增加钾离子的扩散系数，在氩气氛中合成的钛酸盐表面涂有导电碳涂层。X射线相分析、扫描电子显微镜和红外光谱的结果证实了复合材料的形成。在合成复合材料的基础上组装的含钾金属的半电池在 CR2025 外壳中进行了电化学测试，随后计算了比电容、功率密度和能量密度。结果表明，在低扫描速率（1 和 3 mV s ^–1）。结果表明，使用碳涂层可将钾的扩散系数提高到 1.77 × 10 ^–14 cm ² s ^–1/2。