Evaluation and Stability of PEDOT Polymer Electrodes for Li-O2Batteries.
Lithium-air (O2) batteries have shown great promise because of their high gravimetric energy density-an order of magnitude greater than Li-ion-but challenges such as electrolyte and electrode instability have led to poor capacity retention and low cycle life. Positive electrodes such as carbon and inorganic metal oxides have been heavily explored, but the degradation of carbon and the limited surface area of the metal oxides limit their practical use. In this work, we study the electron-conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and show it can support oxygen reduction to form Li2O2in a nonaqueous environment. We also propose a degradation mechanism and show that the formation of sulfone functionalities on the PEDOT surface and cleavage of the polymer repeat unit impairs electron conductivity and leads to poor cycling. Our findings are important in the search for new Li-O2electrodes, and the physical insights provided are significant and timely.
Department of Chemical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.|The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Chibueze V
CV
Amanchukwu
Electrochemical Energy Laboratory, Research Laboratory of Electronics, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Magali
M
Gauthier
Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Thomas P
TP
Batcho
Department of Chemistry, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
Chanez
C
Symister
Electrochemical Energy Laboratory, Research Laboratory of Electronics, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.|Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.|Department of Mechanical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Yang
Y
Shao-Horn
Department of Chemistry, Washington University in St. Louis , St. Louis, Missouri 63130, United States.
Julio M
JM
D'Arcy
Department of Chemical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.|The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
Paula T
PT
Hammond