TY - JOUR
T1 - High-performance lithium-sulfur batteries with a self-supported, 3D Li2S-doped graphene aerogel cathodes
AU - Zhou, Guangmin
AU - Paek, Eunsu
AU - Hwang, Gyeong S.
AU - Manthiram, Arumugam
N1 - Funding Information:
This work was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award No. DE-AR0000377. G.S.H. gratefully acknowledges the Robert A. Welch foundation (F-1535) for partial financial support of the computational work and the Texas Advanced Computing Center (TACC) for providing HPC resources. The authors thank Dr. C. Zu for XPS measurements and Dr. Y. Zhao and Ms. P. Han for helpful discussions.
Publisher Copyright:
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Lithium-sulfur (Li-S) batteries are being considered as the next-generation high-energy-storage system due to their high theoretical energy density. However, the use of a lithium-metal anode poses serious safety concerns due to lithium dendrite formation, which causes short-circuiting, and possible explosions of the cell. One feasible way to address this issue is to pair a fully lithiated lithium sulfide (Li2S) cathode with lithium metal-free anodes. However, bulk Li2S particles face the challenges of having a large activation barrier during the initial charge, low active-material utilization, poor electrical conductivity, and fast capacity fade, preventing their practical utility. Here, the development of a self-supported, high capacity, long-life cathode material is presented for Li-S batteries by coating Li2S onto doped graphene aerogels via a simple liquid infiltration-evaporation coating method. The resultant cathodes are able to lower the initial charge voltage barrier and attain a high specific capacity, good rate capability, and excellent cycling stability. The improved performance can be attributed to the (i) cross-linked, porous graphene network enabling fast electron/ion transfer, (ii) coated Li2S on graphene with high utilization and a reduced energy barrier, and (iii) doped heteroatoms with a strong binding affinity toward Li2S/lithium polysulfides with reduced polysulfide dissolution based on first-principles calculations. 3D N- or B-doped graphene aerogel cathodes provide a highly conductive network and large surface area for Li2S coating, facilitate fast charge transfer, and immobilize effectively the polysulfide ions. This enables a low initial charge voltage barrier, high specific capacity, high rate capability, and excellent cycling stability.
AB - Lithium-sulfur (Li-S) batteries are being considered as the next-generation high-energy-storage system due to their high theoretical energy density. However, the use of a lithium-metal anode poses serious safety concerns due to lithium dendrite formation, which causes short-circuiting, and possible explosions of the cell. One feasible way to address this issue is to pair a fully lithiated lithium sulfide (Li2S) cathode with lithium metal-free anodes. However, bulk Li2S particles face the challenges of having a large activation barrier during the initial charge, low active-material utilization, poor electrical conductivity, and fast capacity fade, preventing their practical utility. Here, the development of a self-supported, high capacity, long-life cathode material is presented for Li-S batteries by coating Li2S onto doped graphene aerogels via a simple liquid infiltration-evaporation coating method. The resultant cathodes are able to lower the initial charge voltage barrier and attain a high specific capacity, good rate capability, and excellent cycling stability. The improved performance can be attributed to the (i) cross-linked, porous graphene network enabling fast electron/ion transfer, (ii) coated Li2S on graphene with high utilization and a reduced energy barrier, and (iii) doped heteroatoms with a strong binding affinity toward Li2S/lithium polysulfides with reduced polysulfide dissolution based on first-principles calculations. 3D N- or B-doped graphene aerogel cathodes provide a highly conductive network and large surface area for Li2S coating, facilitate fast charge transfer, and immobilize effectively the polysulfide ions. This enables a low initial charge voltage barrier, high specific capacity, high rate capability, and excellent cycling stability.
KW - graphene aerogel cathodes
KW - Li-S batteries
KW - lithium sulfide
KW - nitrogen/boron doping
KW - self-supported electrode
UR - http://www.scopus.com/inward/record.url?scp=84955368914&partnerID=8YFLogxK
U2 - 10.1002/aenm.201501355
DO - 10.1002/aenm.201501355
M3 - Article
AN - SCOPUS:84955368914
SN - 1614-6832
VL - 6
JO - Advanced Energy Materials
JF - Advanced Energy Materials
IS - 2
M1 - 1501355
ER -