Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115, USA.
Nanoscale. 2018 Nov 15;10(44):20754-20760. doi: 10.1039/c8nr07268j.
Aqueous batteries designed with K-ions have outstanding potential for future energy storage applications. When coupled with cathode and anode materials both operating with the intercalation mechanism, K-ion batteries could have kinetics and stability similar to Li-ion batteries in principle but with a much lower cost. However, the electrode materials developed so far still suffer from poor stability and limited activity, especially from the anode side. Herein, a new concept of symmetric K-ion batteries was developed by using potassium Prussian blue (KPB) as a bipolar material. The KPB particles were grown on flexible and strong wiper cloth substrates that were pre-coated with polypyrrole (PPy). The use of PPy as an interlayer not only boosted electrical conductivity but also ensured uniform growth of KPB particles. The synthesized KPB@PPy@wiper electrodes have superior flexibility and stability, and exhibited two redox pairs both with remarkable kinetics. When used as bipolar electrodes in combination with a gel solid-state electrolyte, they delivered a well-defined discharge voltage plateau at ∼0.6 V with superior rate capability and cycling stability. This work could provide new insights into the design of K-ion batteries, and give new options for developing flexible solid-state devices.
水系电池设计采用 K 离子，具有出色的未来储能应用潜力。当与同时采用嵌入机制的阴极和阳极材料结合时，K 离子电池在原理上可能具有类似于锂离子电池的动力学和稳定性，但成本要低得多。然而，迄今为止开发的电极材料仍然存在稳定性差和活性有限的问题，特别是在阳极方面。本文通过使用钾普鲁士蓝（KPB）作为双极材料，开发了一种新型对称 K 离子电池概念。KPB 颗粒生长在预先涂有聚吡咯（PPy）的柔性和强擦拭布基底上。使用 PPy 作为夹层不仅提高了电导率，而且确保了 KPB 颗粒的均匀生长。合成的 KPB@PPy@wiper 电极具有优异的柔韧性和稳定性，表现出两个具有显著动力学的氧化还原对。当用作结合凝胶固态电解质的双极电极时，它们在 ∼0.6 V 时呈现出明确的放电电压平台，具有出色的倍率性能和循环稳定性。这项工作为 K 离子电池的设计提供了新的见解，并为开发柔性固态器件提供了新的选择。
