The rapid growth of portable consumer electronics and electric vehicles demands new battery technologies with greater energy stored at a reduced cost. Energy storage solutions based on multivalent metals, such as Mg, could significantly increase the energy density as compared to lithium-ion based technology. In this paper, we employ density functional theory calculations to systematically evaluate the performance, such as thermodynamic stability, ion diffusivity and voltage, of a group of 3d transition-metal sulfur-spinel compounds (21 in total) for multivalent cathode applications. Based on our calculations, Cr2S4, Ti2S4 and Mn2S4 spinel compounds exhibit improved Mg2+ mobility (diffusion activation energy <650 meV) relative to their oxide counterparts, however the improved mobility comes at the expense of lower voltage and thereby lower theoretical specific energy. Ca2+ intercalating into Cr2S4 spinel exhibits a low diffusion activation barrier of 500 meV and a voltage of ∼2 V, revealing a potential cathode for use in Ca rechargeable batteries.
BT - Energy & Environmental Science DA - 10/2016 DO - 10.1039/C6EE01731B IS - 10 LA - eng N2 -The rapid growth of portable consumer electronics and electric vehicles demands new battery technologies with greater energy stored at a reduced cost. Energy storage solutions based on multivalent metals, such as Mg, could significantly increase the energy density as compared to lithium-ion based technology. In this paper, we employ density functional theory calculations to systematically evaluate the performance, such as thermodynamic stability, ion diffusivity and voltage, of a group of 3d transition-metal sulfur-spinel compounds (21 in total) for multivalent cathode applications. Based on our calculations, Cr2S4, Ti2S4 and Mn2S4 spinel compounds exhibit improved Mg2+ mobility (diffusion activation energy <650 meV) relative to their oxide counterparts, however the improved mobility comes at the expense of lower voltage and thereby lower theoretical specific energy. Ca2+ intercalating into Cr2S4 spinel exhibits a low diffusion activation barrier of 500 meV and a voltage of ∼2 V, revealing a potential cathode for use in Ca rechargeable batteries.
PY - 2016 SP - 3201 EP - 3209 ST - Energy Environ. Sci. T2 - Energy & Environmental Science TI - Evaluation of sulfur spinel compounds for multivalent battery cathode applications VL - 9 SN - 1754-5692 ER -