A High Capacity and Working Voltage Potassium‐Based Dual Ion Batteries

Abstract

Potassium‐based dual ion batteries (KDIBs) have attracted significant attention owing to high working voltage, high safety, low processing cost, and environmental friendliness. Nevertheless, one great challenge for practical KDIBs is to develop suitable anode materials with high specific capacity. Herein, we report an architecture of hierarchically porous antimony nanoparticles/carbon nanofibers (HPSbCNFs) as flexible, free‐standing anode for high‐performance KDIBs. The HPSbCNFs with hierarchically porous structure, and high‐content nitrogen doping, not only offer sufficient free space to tolerate the repetitive volume expansion of Sb nanoparticles during long‐term cycling, but also greatly facilitate the transport of electrons and ions within electrode, ensuring high material utilization ratio. Thus, the KDIBs, constituted by HPSbCNFs‐700 (calcined at 700 °C) anode and graphite cathode, exhibited a high reversible capacity of 440 mAh g−1 with high discharge medium voltage of 4.5 V at a specific current of 200 mA g−1 (the highest capacity for all KDIBs normalized by the mass of the anode), and excellent cyclic life. Outstanding electrochemical reversibility of the KDIBs was further demonstrated by ex situ XRD, ex situ Raman spectrum, and HRTEM. These results suggest the as‐designed HPSbCNFs‐700 with high‐capacity and long‐term cycling stability is a promising anode material for high‐performance KDIBs.

Yolk–Shell P3‐Type K0.5[Mn0.85Ni0.1Co0.05]O2: A Low‐Cost Cathode for Potassium‐Ion Batteries

“…The organic cathode materials exhibit a higher specific capacity but poor stability, while the Prussian blue and its derivatives, despite their high operating voltage and capacity, suffer from difficulty in controlling defects and water, which makes it challenging for a large-scale preparation. [11,[48][49][50][51][52] On the other hand, the layered transition metal oxides have a high theoretical capacity and are easy to synthesize for cost-effective mass production. Figure 2f and Table S2 also present the comparison of cycle stability, average voltage, and electrolyte between YS-KMNC and other layered cathode materials for PIBs.…”

Designing g‐C3N4/N‐Rich Carbon Fiber Composites for High‐Performance Potassium‐Ion Hybrid Capacitors

“…[1] Meanwhile, storage of potassium metal is as high as 1.5 wt % in the nature, close to 880 times that of lithium metal, [10] and the standard electrode potential of potassium (−2.936 V vs. standard hydrogen electrode (SHE)) is lower than that of sodium (−2.714 V vs. SHE), which is alike to lithium (−3.04 V vs. SHE). [13,14] Moreover, due to the weak Lewis acidity of potassium ions, solvated potassium ions are smaller than lithium ions and sodium ions, which makes potassium ions have a faster migration rate in the electrolyte. [15] In addition, compared with lithium-and sodium-based electrolytes, there are fewer side reactions on the surface of the anode material in potassium-based electrolytes.…”

Flour derived porous carbon as anode for highly robust potassium-ion batteries

“…To date, various materials have been explored as potential anode candidates for PIBs, including carbon materials, metal oxides, metal sulfides, phosphides, MXene based materials. (Wang et al, 2018;Zhang et al, 2019a;Wu et al, 2019b;Chen et al, 2020;Li et al, 2020;Cao et al, 2021;Deng et al, 2021;Luo et al, 2021;Zhang et al, 2021;Cao et al, 2022). Among them, carbon-based materials present great potential toward commercialization due to their abundant reserve, low prices and excellent electrochemical properties.…”