Key Parameters
Governing the Energy Density of Rechargeable
Li/S Batteries
- Publication date
- Publisher
Abstract
Rechargeable lithium–sulfur
batteries have high theoretical
capacity and energy density. However, their volumetric energy density
has been believed to be lower than that of conventional lithium ion
batteries employing metal oxide cathodes like LiCoO<sub>2</sub>. Here,
we study the effects of sulfur loading percentage, develop a simple
model and calculate the gravimetric and volumetric energy densities
based on the total composition of electrodes in a lithium–sulfur
cell, and compare those results with a typical graphite/LiCoO<sub>2</sub> cell. From the model output, we have identified and established
key parameters governing the energy density of rechargeable Li/S batteries.
We find that the sulfur loading percentage has a much higher impact
on the volumetric energy density than on the gravimetric energy density.
A lithium–sulfur cell can exceed a lithium ion cell’s
volumetric energy density but only at high sulfur loading percentages
(ca. 70%). We believe that these findings may attract more attention
of lithium–sulfur system studies to high sulfur loading levels