title: Feasibility of Full (Li-Ion)-O2Cells Comprised of Hard Carbon Anodes.
abstract: Aprotic Li-O2battery is an exciting concept. The enormous theoretical energy density and cell assembly simplicity make this technology very appealing. Nevertheless, the instability of the cell components, such as cathode, anode, and electrolyte solution during cycling, does not allow this technology to be fully commercialized. One of the intrinsic challenges facing researchers is the use of lithium metal as an anode in Li-O2cells. The high activity toward chemical moieties and lack of control of the dissolution/deposition processes of lithium metal makes this anode material unreliable. The safety issues accompanied by these processes intimidate battery manufacturers. The need for a reliable anode is crucial. In this work we have examined the replacement of metallic lithium anode in Li-O2cells with lithiated hard carbon (HC) electrodes. HC anodes have many benefits that are suitable for oxygen reduction in the presence of solvated lithium cations. In contrast to lithium metal, the insertion of lithium cations into the carbon host is much more systematic and safe. In addition, with HC anodes we can use aprotic solvents such as glymes that are suitable for oxygen reduction applications. By contrast, lithium cations fail to intercalate reversibly into ordered carbon such as graphite and soft carbons using ethereal electrolyte solutions, due to detrimental co-intercalation of solvent molecules with Li ions into ordered carbon structures. The hard carbon electrodes were prelithiated prior to being used as anodes in the Li-O2rechargeable battery systems. Full cells containing diglyme based solutions and a monolithic carbon cathode were measured by various electrochemical methods. To identify the products and surface films that were formed during cells operation, both the cathodes and anodes were examined ex situ by XRD, FTIR, and electron microscopy. The HC anodes were found to be a suitable material for (Li-ion)-O2cell. Although there are still many challenges to tackle, this study offers a more practical direction for this promising battery technology and sets up a platform for further systematic optimization of its various components.
authors: Department of Chemistry, Bar Ilan University , Ramat-Gan 52900, Israel.
authors: Daniel
authors: D
authors: Hirshberg
authors: Department of Chemistry, Bar Ilan University , Ramat-Gan 52900, Israel.
authors: Daniel
authors: D
authors: Sharon
authors: Department of Chemistry, Bar Ilan University , Ramat-Gan 52900, Israel.
authors: Ezequiel
authors: E
authors: De La Llave
authors: Department of Chemistry, Bar Ilan University , Ramat-Gan 52900, Israel.
authors: Michal
authors: M
authors: Afri
authors: Department of Chemistry, Bar Ilan University , Ramat-Gan 52900, Israel.
authors: Aryeh A
authors: AA
authors: Frimer
authors: Department of Energy Engineering, Hanyang University , Seoul 133-791, South Korea.
authors: Won-Jin
authors: WJ
authors: Kwak
authors: Department of Energy Engineering, Hanyang University , Seoul 133-791, South Korea.
authors: Yang-Kook
authors: YK
authors: Sun
authors: Department of Chemistry, Bar Ilan University , Ramat-Gan 52900, Israel.
authors: Doron
authors: D
authors: Aurbach
keywords: FTIR; Li−O2 batteries; XRD; glyme solvents; hard carbon; lithium metal