Kinetically Enhanced Electrochemical Redox of Polysulfides on Polymeric Carbon Nitrides for Improved Lithium-Sulfur Batteries.
The kinetics and stability of the redox of lithium polysulfides (LiPSs) fundamentally determine the overall performance of lithium-sulfur (Li-S) batteries. Inspired by theoretical predictions, we herein validated the existence of a strong electrostatic affinity between polymeric carbon nitride (p-C3N4) and LiPSs, that can not only stabilize the redox cycling of LiPSs, but also enhance their redox kinetics. As a result, utilization of p-C3N4 in a Li-S battery has brought much improved performance in the aspects of high capacity and low capacity fading over prolonged cycling. Especially upon the application of p-C3N4, the kinetic barrier of the LiPS redox reactions has been significantly reduced, which has thus resulted in a better rate performance. Further density functional theory simulations have revealed that the origin of such kinetic enhancement was from the distortion of molecular configurations of the LiPSs anchored on p-C3N4. Therefore, this proof-of-concept study opens up a promising avenue to improve the performance of Li-S batteries by accelerating their fundamental electrochemical redox processes, which also has the potential to be applied in other electrochemical energy storage/conversion systems.
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , 72 Wenhua Road, Shenyang, Liaoning 110016, China.
Ji
J
Liang
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , 72 Wenhua Road, Shenyang, Liaoning 110016, China.
Lichang
L
Yin
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , 72 Wenhua Road, Shenyang, Liaoning 110016, China.|School of Chemical Engineering, Shandong University of Technology , 266 Cunxi Road, Zibo, Shandong 255000, China.
Xiaonan
X
Tang
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , 72 Wenhua Road, Shenyang, Liaoning 110016, China.|School of Physical Science and Technology, Shanghai Tech University , Shanghai 200031, China.
Huicong
H
Yang
National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China , Hefei, Anhui 230029, China.
Wensheng
W
Yan
National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China , Hefei, Anhui 230029, China.
Li
L
Song
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , 72 Wenhua Road, Shenyang, Liaoning 110016, China.
Hui-Ming
HM
Cheng
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , 72 Wenhua Road, Shenyang, Liaoning 110016, China.
Feng
F
Li
adsorption; carbon nitride; graphene; lithium polysulfide; redox kinetics