Aqueous rechargeable metal-ion batteries (ARMBs) hold intrinsic advantages of high safety, low cost and environmental benignity for large scale energy storage technologies. However, the research on aqueous K-ion batteries (AKIBs) was hindered by limited materials. Herein, a novel AKIB was reported by employing environment-friendly 1,4,5,8-naphthalenetetracarboxylic dianhydride-derived polyimide (PNTCDA) as anode and Berlin green (FeHCF) as cathode. Both electrodes have high rate performance and excellent capacity retention during cycling. Kinetics researches verify the superior electrochemical property of PNTCDA in saturated KNO₃ solution. In-situ XRD of FeHCF demonstrates the unique shift of peak position and negligible distortion of lattice during the insertion/extraction of K⁺. The AKIB exhibits an attractive energy density of 46.9 Wh/kg and a high capacity retention of 74% in 300 cycles. More importantly, the battery can reach a super-high power of 2079.1 W/kg with an energy density of 24.2 Wh/kg, ranking relatively high among the ARIMs. This system extends the use of polyimide and points a way of AKIBs for grid-scale energy storage.

水性可充电金属离子电池（ARMB）具有大规模能源存储技术的高安全性，低成本和环境友好的内在优势。然而，有限的材料阻碍了对水性K离子电池（AKIBs）的研究。在本文中，报道了一种新颖的AKIB，其采用环境友好的1,4,5,8-萘四甲酸二酐衍生的聚酰亚胺（PNTCDA）作为阳极，并采用柏林绿（FeHCF）作为阴极。这两个电极在循环过程中均具有高倍率性能和出色的容量保持率。动力学研究证明，PNTCDA在饱和KNO ₃溶液中具有优异的电化学性能。FeHCF的原位XRD显示了在K ⁺的插入/提取过程中峰位置的独特位移和晶格的可忽略不计。AKIB在300个循环中展现出46.9 Wh / kg的有吸引力的能量密度和74％的高容量保持率。更重要的是，电池可以达到2079.1 W / kg的超高功率，能量密度为24.2 Wh / kg，在ARIM中排名较高。该系统扩展了聚酰亚胺的使用范围，并指出了用于电网规模储能的AKIB。