TY - JOUR
T1 - Rational Design of Lithium-Sulfur Battery Cathodes Based on Experimentally Determined Maximum Active Material Thickness
AU - Klein, Michael J.
AU - Veith, Gabriel M.
AU - Manthiram, Arumugam
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/7/12
Y1 - 2017/7/12
N2 - Rational design of conductive carbon hosts for high energy density lithium-sulfur batteries requires an understanding of the fundamental limitations to insulating active material loading. In this work, we investigate the electrochemistry of lithium sulfide films ranging in thickness from 30 to 3500 nm. We show that films thicker than approximately 40 nm cannot be charged at local charge densities above 1 μA cm-2, and by implication, the maximum useful pore diameter is near 60 nm in a practical cathode. "Activation" overpotentials for Li2S are identified in thicker films, resulting from polysulfide generation, but are shown not to improve the fundamental areal charge limitations. We develop a model for filling of conductive pores with active material to rationally design composites based on local charge density. For low-electrolyte applications, the importance of matching micropore volume to sulfide loading and cycling rate is emphasized.
AB - Rational design of conductive carbon hosts for high energy density lithium-sulfur batteries requires an understanding of the fundamental limitations to insulating active material loading. In this work, we investigate the electrochemistry of lithium sulfide films ranging in thickness from 30 to 3500 nm. We show that films thicker than approximately 40 nm cannot be charged at local charge densities above 1 μA cm-2, and by implication, the maximum useful pore diameter is near 60 nm in a practical cathode. "Activation" overpotentials for Li2S are identified in thicker films, resulting from polysulfide generation, but are shown not to improve the fundamental areal charge limitations. We develop a model for filling of conductive pores with active material to rationally design composites based on local charge density. For low-electrolyte applications, the importance of matching micropore volume to sulfide loading and cycling rate is emphasized.
UR - http://www.scopus.com/inward/record.url?scp=85024364671&partnerID=8YFLogxK
U2 - 10.1021/jacs.7b03380
DO - 10.1021/jacs.7b03380
M3 - Article
C2 - 28636354
AN - SCOPUS:85024364671
SN - 0002-7863
VL - 139
SP - 9229
EP - 9237
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 27
ER -