Ball‐Milling Strategy for Fast and Stable Potassium‐Ion Storage in Antimony‐Carbon Composite Anodes

Abstract

Potassium‐ion batteries (PIBs) have been considered as promising alternatives to lithium‐ion batteries in large‐scale energy storage systems owing to the high earth abundance and low cost of potassium resources. However, the large radius of the K ion hinders the development of suitable electrode materials. Herein, with commercial antimony (Sb) and mesoCarbon microbead (MCMB) powders as low‐cost raw materials, a facile ball‐milling strategy is developed for constructing high‐performance Sb−C composite electrodes. The as‐prepared Sb@MCMB‐3 electrode exhibits high reversible capacity (525.4 mAh g−1 at 100 mA g−1), superior rate capability (293.9 mAh g−1 at 5000 mA g−1) and stable cycling performance (497.5 mAh g−1 after 80 cycles at 100 mA g−1 and 300.1 mAh g−1 after 500 cycles at 1.0 A g−1). With consecutive CV measurements, the galvanostatic intermittent titration technique, and Randle‐Sevcik equation, the K‐ion diffusion kinetics are insightfully evaluated. Therefore, this work may broaden the pathways for the commercialization of PIBs.

Rational Regulation of Cu−Co Thiospinel Hierarchical Microsphere to Enhance the Supercapacitive Properties

“…As shown in Figures 6(b) and S6, the oxidation current density is linear with the square root of the scanning rate, demonstrating that the electrochemical reaction is the diffusion‐controlled process [24] . The apparent diffusion coefficient ( D ) of OH − ions is calculated according to the Randles–Sevcik equation: [25] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr i{_{{\rm p}}}=2.69\times 10{^{5}}\times n{^{3/2}}\times A\times D{^{1/2}}\times C\times v{^{1/2}}\hfill\cr}}$$$ …”

“…[23] As shown in Figures 6(b) and S6, the oxidation current density is linear with the square root of the scanning rate, demonstrating that the electrochemical reaction is the diffusion-controlled process. [24] The apparent diffusion coefficient (D) of OH À ions is calculated according to the Randles-Sevcik equation: [25] i p ¼ 2:69…”

A Comparative Study on the K-ion Storage Behavior of Commercial Carbons

“…Despite carbons, various anode materials with high reversible capacities were also reported, especially the conversiontype (FeS2, [42] CoS2, [43] etc.) and alloying-type (Sb, [44,45] P, [46,47] Bi, [48,49] Sb2S3, [50,51] SnS2, [52][53][54] Sn4P3, [55][56][57][58] etc.) materials.…”