Aqueous K-ion battery incorporating environment-friendly organic compound and Berlin green

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 Kion 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.

Organic Electrode Materials for Non-aqueous K-Ion Batteries

The demands for high-performance and low-cost batteries make K-ion batteries(KIBs) considered as promising supplements or alternatives for Li-ion batteries(LIBs). Nevertheless, there are only a small amount of conventional inorganic electrode materials that can be used in KIBs, due to the large radius of K^+ ions. Diff erently, organic electrode materials(OEMs) generally own sufficiently interstitial space and good structure flexibility, which can maintain superior performance in K-ion systems. Therefore, in recent years, more and more investigations have been focused on OEMs for KIBs. This review will comprehensively cover the researches on OEMs in KIBs in order to accelerate the research and development of KIBs. The reaction mechanism, electrochemical behavior, etc., of OEMs will all be summarized in detail and deeply. Emphasis is placed to overview the performance improvement strategies of OEMs and the characteristic superiority of OEMs in KIBs compared with LIBs and Na-ion batteries.