Kim B S Do-Hoon, Lee M S Byungju, Park Kyu-Young, Kang Kisuk
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.
Chem Asian J. 2016 Apr 20;11(8):1288-92. doi: 10.1002/asia.201600007. Epub 2016 Mar 17.
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.
锂硫化学因其高比能量（1675 mA h g⁻¹）而被视为下一代电池系统的一个有前景的候选者。尽管该系统存在诸如低循环稳定性和功率能力等问题仍有待解决，但已经进行了广泛的实验研究来解决这些问题。对反应机理及其反应产物有一个基本的了解将进一步推动锂硫电池的发展。在此，我们使用第一性原理计算研究了传统锂硫电池放电产物硫化锂（Li₂S）的电荷传输机制。我们的计算表明，在各种可能的电荷载流子中，主要的电荷传输由锂离子空位主导。此外，大的带隙和低浓度的电子极化子表明，电子传导对Li₂S中的电荷传输机制贡献可忽略不计。
