Jeong, Min-Gi Kwak, Won-Jin Islam, Mobinul Park, Jiwon Byon, Hye Ryung Jang, Minchul Sun, Yang-Kook Jung, Hun-Gi 2024-01-19T20:34:36Z 2024-01-19T20:34:36Z 2021-09-02 2019-02-07 0013-4651 https://pubs.kist.re.kr/handle/201004/120357 This paper presents the synthesis and characterization of triple hierarchical porous carbon spheres as cathodes in lithium-oxygen batteries. The porous carbon cathode exhibits a higher discharge capacity and average discharge potential compared to a typical carbon black cathode. This superior electrochemical result can be attributed to the triple hierarchical pores of the cathode: micropores that act as channels for oxygen to flow without interruption by the accumulated discharge product, abundant mesopores that shape the size of the discharge product and transport the electrolyte, and macropores that easily accommodate the accumulation of discharge product. To further promote Li2O2 formation/decomposition, the cathode can be decorated with a Ru catalyst, which strongly influences the oxygen evolution reaction performance. Conspicuously, triple hierarchical porous carbon spheres exhibit a homogeneous distribution of the Ru catalyst and thus provide an appropriate architecture. The synergistic effect from the unique structure and catalytic competence of Ru increases the capacity and rate capability with lower over-potential, and facilitates the formation of Li2O2. This can be decomposed at a low potential during recharge and thus contributes to the very high energy efficiency. (C) 2019 The Electrochemical Society. English ELECTROCHEMICAL SOC INC ORDERED MESOPOROUS CARBON OXYGEN REDUCTION REACTION SURFACE-AREA METAL PERFORMANCE GRAPHENE RECHARGEABILITY REVERSIBILITY ELECTRODES CATALYSTS Triple Hierarchical Porous Carbon Spheres as Effective Cathodes for Li-O-2 Batteries Article 10.1149/2.0021904jes 1 JOURNAL OF THE ELECTROCHEMICAL SOCIETY, v.166, no.4, pp.A455 - A463 JOURNAL OF THE ELECTROCHEMICAL SOCIETY 166 4 A455 A463 scie scopus 000458101100003 2-s2.0-85063144460 Electrochemistry Materials Science, Coatings & Films Electrochemistry Materials Science Article ORDERED MESOPOROUS CARBON OXYGEN REDUCTION REACTION SURFACE-AREA METAL PERFORMANCE GRAPHENE RECHARGEABILITY REVERSIBILITY ELECTRODES CATALYSTS