Cai Jiazhen, Ding Yifang, Bai Ruijun, Zhang Chengwei, Zhang Xin, Sun Hongtao, Wang Gongkai
Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, School of Material Science and Engineering, Hebei University of Technology, Tianjin 300130, China.
The Harold & Inge Marcus Department of Industrial & Manufacturing Engineering, Materials Research Institute (MRI), The Pennsylvania State University, University Park 16802, PA, USA.
J Colloid Interface Sci. 2023 Dec;651:534-543. doi: 10.1016/j.jcis.2023.08.015. Epub 2023 Aug 5.
Potassium-based energy storage has emerged as a promising alternative for advanced energy storage systems, driven by the abundance of potassium, fast ion migration, and low standard electrode potential. Hybrid capacitors, which combine the desirable characteristics of batteries and supercapacitors, offer a compelling solution for efficient energy storage. In this study, we present the development of versatile composite materials, specifically potassium vanadium fluorophosphate (KVPOF) composites, utilizing a sol-gel method. These composites enable tunable potassium storage and charge transport kinetics within regulated voltage windows, serving as both cathode and anode materials. The anode composite, composed of KVPOF and hierarchical porous carbon (HPC), exhibited exceptional stability over 400 cycles within a low-voltage window. On the other hand, the cathode composite, consisting of battery-like KVPOF and physisorption activated carbon (AC), demonstrated great potential as a cathode material, striking a balance between specific energy and cycle life within a regulated high-voltage window. By integrating KVPOF/C as the anode and KVPOF/AC as the cathode, we successfully created potassium-ion hybrid capacitors (PIHCs) that showcased an impressive capacity retention of 83% after 10,000 cycles within a high voltage window of 0.5-4.3 V. Furthermore, to explore the application of these materials in miniaturized energy storage, we fabricated potassium-ion micro hybrid capacitors (PIMHCs) with interdigitated electrodes. These devices exhibited a high areal energy density of 18.8 μWh cm at a power density of 111.6 μW cm, indicating their potential for compact energy storage systems. The results of this study demonstrate the versatility and efficacy of the developed KVPO4F composite materials, highlighting their potential for future advancements in potassium-based energy storage technologies.
由于钾资源丰富、离子迁移速度快以及标准电极电位低，钾基储能已成为先进储能系统的一种有前景的替代方案。混合电容器结合了电池和超级电容器的理想特性，为高效储能提供了一个有吸引力的解决方案。在本研究中，我们展示了利用溶胶 - 凝胶法开发多功能复合材料，特别是氟磷酸钾钒（KVPOF）复合材料的过程。这些复合材料在规定的电压窗口内实现了可调的钾存储和电荷传输动力学，可同时用作阴极和阳极材料。由KVPOF和分级多孔碳（HPC）组成的阳极复合材料在低电压窗口内经过400次循环表现出优异的稳定性。另一方面，由类似电池的KVPOF和物理吸附活性炭（AC）组成的阴极复合材料作为阴极材料显示出巨大潜力，在规定的高电压窗口内实现了比能量和循环寿命之间的平衡。通过将KVPOF/C用作阳极和KVPOF/AC用作阴极，我们成功制备了钾离子混合电容器（PIHC），在0.5 - 4.3 V的高电压窗口内经过10000次循环后，其容量保持率高达83%。此外，为了探索这些材料在小型化储能中的应用，我们制备了具有叉指电极的钾离子微型混合电容器（PIMHC）。这些器件在功率密度为111.6 μW/cm²时表现出18.8 μWh/cm²的高面积能量密度，表明它们在紧凑型储能系统中的潜力。本研究结果证明了所开发的KVPO4F复合材料的多功能性和有效性，突出了它们在钾基储能技术未来发展中的潜力。
