title: The Effect of Potassium Impurities Deliberately Introduced into Activated Carbon Cathodes on the Performance of Lithium-Oxygen Batteries.
abstract: Rechargeable lithium-air (Li-O2) batteries have drawn much interest owing to their high energy density. We report on the effect of deliberately introducing potassium impurities into the cathode material on the electrochemical performance of a Li-O2 battery. Small amounts of potassium introduced into the activated carbon (AC) cathode material in the synthesis process are found to have a dramatic effect on the performance of the Li-O2 cell. An increased amount of potassium significantly increases capacity, cycle life, and round-trip efficiency. This improved performance is probably due to a larger amount of LiO2 in the discharge product, which is a mixture of LiO2 and Li2O2, resulting from the increase in the amount of potassium present. No substantial correlation with porosity or surface area in an AC cathode is found. Experimental and computational studies indicate that potassium can act as an oxygen reduction catalyst, which can account for the dependence of performance on the amount of potassium.
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA.
authors.forename: Dengyun
authors.initials: D
authors.lastname: Zhai
authors.affiliation: Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA.
authors.forename: Kah Chun
authors.initials: KC
authors.lastname: Lau
authors.affiliation: Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA.
authors.forename: Hsien-Hau
authors.initials: HH
authors.lastname: Wang
authors.affiliation: Electron Microscopy Center, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wen
authors.affiliation: Electron Microscopy Center, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA.
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Miller
authors.affiliation: Graduate School at Shenzhen, Tsinghua University, The University Town, Shenzhen, 518055, PR China.
authors.forename: Feiyu
authors.initials: F
authors.lastname: Kang
authors.affiliation: Graduate School at Shenzhen, Tsinghua University, The University Town, Shenzhen, 518055, PR China.
authors.forename: Baohua
authors.initials: B
authors.lastname: Li
authors.affiliation: Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM, 87185, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Zavadil
authors.affiliation: Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA. curtiss@anl.gov.
authors.forename: Larry A
authors.initials: LA
authors.lastname: Curtiss
mesh_terms: D002384:Catalysis; D002606:Charcoal / Q000737:chemistry*; D011211:Electric Power Supplies; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry*
chemical_list: D002606:Charcoal; D008094:Lithium; D011188:Potassium; D010100:Oxygen
keywords: batteries; carbon; lithium; oxygen; potassium