122nd General Meeting of the KCS

Type Poster Presentation
Area Electrochemistry
Room No. Grand Ballroom
Time 10월 19일 (금요일) 11:00~12:30
Code ELEC.P-482
Subject Calcium Storage in Natural Graphite as an Anode for Calcium Ion Battery
Authors Prabakar Richard, Myoungho Pyo*
Department of Printed Electronics Engineering, Suncheon National University, Korea
Abstract The development in calcium ion battery technology (CIB) has been primarily limited by the difficulties in the lack of a reliable cathode/anode material which is capable of reversible intercalation and de-intercalation of Ca2+ ion. The insertion of divalent cation in graphite (Gt) in particular has been difficult due to the high polarization, larger size and energy density of the cations (e.g., Ca2+, Mg2+). Natural Gt which has been well known anode material for Li ion battery has seldom been studied as a suitable anode in divalent ions. Here we report for the first time successful electrochemical co-intercalation of solvated-Ca2+ ions in Gt in an ether based electrolyte. The Gt is able to exhibit exceptionally high stability for solvated-Ca2+ co-intercalation/de-intercalation at very high rates with a reversible capacity reaching ~60 mAhg-1. We observed the solvated-Ca ion storage mechanism in Gt using in operando X-ray diffraction studies. The formation of various stages was observed with the solvated-Ca ion and was quantified, wherein the highest staging observed was to be stage-2. The configuration of various stages in Gt is proposed by DFT calculation based on the experimental results and calculations explaining the difficulty in the formation of stage-1 type Gt intercalation compound (GIC) and observable capacity are described. The rapid intercalation of solvated-Ca ion in Gt is demonstrated by optical observations, using highly oriented pyrolytic graphite (HOPG), in which the electrochemical intercalation of solvated Ca ions were observed by a corresponding volume increase.
E-mail richiechem@gmail.com