Novel Lamellar Tetrapotassium Pyromellitic Organic for Robust High‐Capacity Potassium Storage

Abstract

Redox‐active organics are investigation hotspots for metal ion storage due to their structural diversity and redox reversibility. However, they are plagued by limited storage capacity, sluggish ion diffusion kinetics, and weak structural stability, especially for K+ ion storage. Herein, we firstly reported the lamellar tetrapotassium pyromellitic (K4PM) with four active sites and large interlayer distance for K+ ion storage based on a design strategy, where organics are constructed with the small molecular mass, multiple active sites, fast ion diffusion channels, and rigid conjugated π bonds. The K4PM electrode delivers a high capacity up to 292 mAh g−1 at 50 mA g−1, among the best reported organics for K+ ion storage. Especially, it achieves an excellent rate capacity and long‐term cycling stability with a capacity retention of ≈83 % after 1000 cycles. Incorporating in situ and ex‐situ techniques, the K+ ion storage mechanism is revealed, where conjugated carboxyls are reversibly rearranged into enolates to stably store K+ ions. This work sheds light on the rational design and optimization of organic electrodes for efficient metal ion storage.

Organic–Inorganic Hybridization Engineering of Polyperylenediimide Cathodes for Efficient Potassium Storage

“…Recently, potassium‐ion batteries (PIBs) have attracted intensive attentions as a promising alternative for lithium‐ion batteries due to their low cost, abundant reserves on the earth, weak Lewis acidity, and lower redox potential of K/K + (−2.93 V) [1–3] . While, one enormous challenge for PIBs is to develop suitable cathode hosts for efficient insertion/extraction of the K + with a large ionic size for high‐performance PIBs [4–6] . Among the retrieved cathode electrodes so far, the emerging organic materials are of great interest for advanced PIBs [7–9] .…”

In Situ Monitoring the Potassium-Ion Storage Enhancement in Iron Selenide with Ether-Based Electrolyte

“…Meanwhile, due to different reaction environments of electrodes in ether‐based electrolytes, some unconventional electrochemical reaction phenomena compared with that in carbonate-based (some named as ester-based) electrolytes occur and the detailed mechanism is still unclear. Utilizing in situ techniques to monitor the electrochemical reaction of electrodes and probing the underlying mechanism in ether‐based electrolytes have become necessary [ 31 – 33 ].…”

Two‐Dimensional Organic/Inorganic Hybrid Nanosheet Electrodes for Enhanced Electrical Conductivity toward Stable and High‐Performance Sodium‐Ion Batteries

“…However, LIB systems are not cost‐effective for large‐scale electrical‐energy storage due to the high cost of Li; thus, there is an urgent demand for alternative systems capable of large‐scale energy storage [3] . In this regard, intensive research efforts have been devoted to sodium‐ion battery (SIB) systems, as Na is one of the most abundant elements in the Earth's crust [4–11] …”