title: First-principles Study on the Charge Transport Mechanism of Lithium Sulfide (Li2 S) in Lithium-Sulfur Batteries.
abstract: The lithium-sulfur chemistry is regarded as a promising candidate for next-generation battery systems because of its high specific energy (1675 mA h g(-1) ). Although issues such as low cycle stability and power capability of the system remain to be addressed, extensive research has been performed experimentally to resolve these problems. Attaining a fundamental understanding of the reaction mechanism and its reaction product would further spur the development of lithium-sulfur batteries. Here, we investigated the charge transport mechanism of lithium sulfide (Li2 S), a discharge product of conventional lithium-sulfur batteries using first-principles calculations. Our calculations indicate that the major charge transport is governed by the lithium-ion vacancies among various possible charge carriers. Furthermore, the large bandgap and low concentration of electron polarons indicate that the electronic conduction negligibly contributes to the charge transport mechanism in Li2 S.
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Republic of Korea.
authors.forename: B S Do-Hoon
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Republic of Korea.|Center for Nanoparticles Research, Institute for Basic Science (IBS), Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Republic of Korea.
authors.forename: M S Byungju
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Republic of Korea.|Center for Nanoparticles Research, Institute for Basic Science (IBS), Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Republic of Korea.
authors.forename: Kyu-Young
authors.initials: KY
authors.lastname: Park
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Republic of Korea. matlgen1@snu.ac.kr.|Center for Nanoparticles Research, Institute for Basic Science (IBS), Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Republic of Korea. matlgen1@snu.ac.kr.
authors.forename: Kisuk
authors.initials: K
authors.lastname: Kang
keywords: conductivity calculation; first-principles calculation; lithium-sulfide cathode; lithium-sulfur batteries; voltage polarization