Rapid and Up‐Scalable Flash Fabrication of Graphitic Carbon Nanocages for Robust Potassium Storage

Abstract

Graphitic carbon nanocages (CNCs) have garnered attention as viable candidates for potassium storage, primarily due to their notable crystallinity, large surface area, and rich porosity. Yet, the development of a rapid, scalable, and economically feasible synthesis approach for CNCs persists as a formidable challenge. This study presents a rapid (millisecond‐scale) and scalable (gram‐scale) method for fabricating mesoporous CNCs characterized by high purity and orderly graphitic structures, utilizing the flash Joule heating technique. Employed for potassium storage, the CNC electrode developed herein exhibits exceptional performance metrics, including initial capacity, rate capability, and cycling stability, surpassing numerous carbonaceous materials previously documented. Impressively, it delivers a high initial capacity of 312.3 mAh g−1 at 0.1 A g−1, maintains 175.1 mAh g−1 at a high rate of 2.0 A g−1, and retains 219.6 mAh g−1 over 1000 cycles at 1.0 A g−1. Molecular dynamics simulations and in situ characterizations are employed to elucidate this robust behavior. This work underscores the significant advantages of the flash Joule heating technique in synthesizing carbonaceous materials for potassium storage applications.

Recent advances in rational design for high-performance potassium-ion batteries

“…320–323 Therefore, intercalation-type compounds are mainly carbon materials, including graphite, hard carbon, and soft carbon. 34,321,324–335 Furthermore, some titanium-based oxide materials also follow the insertion mechanism to store potassium. 336,337 Conversion-type materials are largely composed of metal oxides, sulfides, and selenides.…”

“…Constructing graphite nanostructures that can withstand large volume variations, such as porous and hollow structures, is one of the effective ways to improve the cycling stability and rate capability of graphite materials in PIBs. 335,375,451–464 Cao et al 375 prepared highly graphitized carbon nanocages (CNCs) through high temperature treatment of Ketjen carbon black at 2800 °C under an Ar atmosphere. This cage structure can effectively avoid interlayer slippage and ensure structural integrity, thereby effectively accommodating strain relaxation during K + intercalation/deintercalation, thus improving cycle performance (Fig.…”

“…Intriguingly, CNCs can also be synthesized in hundreds of milliseconds using flash Joule heating (FJH) technology. 335 A typical FJH reaction system mainly consists of three parts: an electrode rod, a quartz tube, and a graphite plug (Fig. 34e).…”