Engineering of Crosslinked Network and Functional Interlayer to Boost Cathode Performance of Tannin for Potassium Metal Batteries

Abstract

Potassium metal batteries (PMBs) are a compelling technology for large-scale energy storage due to the abundance of potassium resources and high energy density. A vital obstacle to construct high-performance PMBs is developing superior cathode materials. Tannin, a plant polyphenol, holding many active sites for redox reactions, is an auspicious high-capacity cathode. However, the relatively poor conductivity and slight solubility in electrolyte deteriorate its capacity and cycle stability. Herein, the tannin is activated through a crosslinking reaction with polyaniline to obtain a composite cathode (i.e., ATN). It exhibits a high initial capacity of 172 mAh g −1 at 50 mA g −1 , based on the electrochemical reaction mechanisms of embedding/releasing of K + on CO and PF 6 − on NH. Moreover, to improve the cycling performance, a graphene oxide modified separator is developed to effectively retard the ATN shuttle. As a result, the capacity retention is significantly enhanced, for example, 82% over 300 cycles at 50 mA g −1 . From a practical aspect, a full PMB of K@K x P y ||ATN is built up, displaying high energy/power density and superior cycling stability, which is a step forward in the development of PMBs.

Formation of Mn–Ni Prussian Blue Analogue Spheres as a Superior Cathode Material for Potassium-Ion Batteries

“…However, the rarity of lithium resources inevitably limits its large-scale application . Compared with LIBs, potassium-ion batteries (PIBs) have attracted extensive attention from researchers recently on account of their low cost and wide distribution. − The most significant merit of PIBs is the negative potential of K/K + (−2.93 V vs standard hydrogen electrode (SHE)), lower than that of Na/Na + (−2.71 V vs SHE). , Moreover, graphitic carbon (a widely used anode material in LIBs) can be employed in PIBs but cannot be used in sodium-ion batteries (SIBs) . Therefore, though it is difficult to find electrode materials for large K + , a series of materials have been designed for PIBs. − …”

Ultrastable Bioderived Organic Anode Induced by Synergistic Coupling of Binder/Carbon-Network for Advanced Potassium-Ion Storage

“…Potassium-ion batteries (PIBs) are promising energy storage devices because of the abundance of potassium resources and the low redox potential of K/K + (−2.93 V vs standard hydrogen electrode, higher than −2.71 V of Na + /Na). − Meanwhile, the low-cost and lighter Al can be used as the current collector on the anode side instead of expensive Cu because potassium forms no alloys with Al and, also, addresses the over-discharge problem. , Due to the larger ionic radius of K + (1.38 Å) compared to that of Li + (0.76 Å), conventional inorganic electrode materials have limitations for use in PIBs, as more severe volume expansion leads to poor cycle life and sluggish reaction kinetics during K + insertion/extraction. − In contrast, organic potassium-ion batteries (OPIBs) have attracted significant attention recently in view of their sustainability, low cost, structure diversity, and high energy density. − Biomass organic molecules, in particular, are widely available from biomass and are biodegradable, making them significantly greener than other organic molecules from petrochemicals. − However, exploitation of innovative and high-performance organic electrodes remains a primary goal for the commercialization of OPIBs.…”

In situ quantitative polymerization of dopamine on dual functional carbon nanotubes as high stability and rate capacity anodes for potassium ion storage

“…6b)), indicating that K + was more prone to bind to the carbonyl group. 20 Three stages were simulated using the molecular electrostatic potential (ESP) method. As shown in Fig.…”

“…Renewable organic matter extracted from nature has a wide range of applications as organic electrode materials. Their degradation will not pollute the environment and they may replace metal ions as active substances such as covalent organic framework (COF) based organic materials, 17,18 biomass small molecules, 19,20 metal-organic frameworks (MOF), 21,22 organic polymers, 23,24 and so on. Dopamine, the most abundant catecholamine neurotransmitter in biology, is used to help cells transmit impulses, as well as used in ion storage and electron conduction in batteries.…”