Impact of Degree of Graphitization, Surface Properties and Particle Size Distribution on Electrochemical Performance of Carbon Anodes for Potassium‐Ion Batteries. Issue 6 (9th March 2022)

• Record Type: Journal Article
• Authors: Wrogemann, Jens M.; Fromm, Olga; Deckwirth, Fabian; Beltrop, Kolja; Heckmann, Andreas; Winter, Martin; Placke, Tobias
• Is Part Of: Batteries & supercaps. Volume 5:Issue 6(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-09
• Subjects: carbonaceous anodes -- degree of graphitization -- graphite -- potassium-ion batteries -- voltage hysteresis; Electrochemistry -- Periodicals; Electrodes -- Periodicals; Electric batteries -- Periodicals; 621.31242
• DOI: 10.1002/batt.202200045
• Languages: English
• ISSNs: 2566-6223

Abstract

Abstract: Carbons are considered as anode active materials in potassium‐ion batteries (PIBs). Here, the correlation between material properties of disordered (non‐graphitic) and ordered graphitic carbons and their electrochemical performance in carbon||K metal cells is evaluated. First, carbons obtained from heat treatment of petroleum coke at temperatures from 800 to 2800 °C are analyzed regarding their microstructure and surface properties. Electrochemical performance metrics for K + ion storage like specific capacity and Coulombic efficiency ( C Eff ) are correlated with surface area, non‐basal planes and microstructure properties, and compared to Li + ion storage. For disordered carbons, the specific capacity can be clearly correlated with the defect surface area. For highly ordered graphitic carbons, the degree of graphitization strongly determines the specific capacity. The initial C Eff of graphitic carbons shows a strong correlation with basal and non‐basal planes. Second, kinetic limitations of ordered graphitic carbons are re‐evaluated by analyzing commercial graphites regarding particle size and surface properties. A clear correlation between particle size, surface area and well‐known challenges of graphitic carbons in terms of low‐rate capability and voltage hysteresis is observed. This work emphasizes the importance of bulk and surface material properties for K + ion storage and gives important insights for future particle design of promising carbon anodes for PIB cells. Abstract : Relates K‐ion battery performance to anode structure : Carbonaceous anodes are considered as promising anode material for potassium‐ion batteries. Here, important material properties of carbons are systematically studied and correlated with their electrochemical performance. Specific capacity, Coulombic efficiency, rate capability and voltage hysteresis can be clearly linked to structural and surface properties, like degree of graphitization, surface area and particle size. This study gives fundamental insights for the understanding of K + ion storage in carbonaceous anodes.