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Soutenance publique de thèse de doctorat en Sciences chimiques - XING Pengcheng

Designing Transition Metal Oxides as Cathode Materials for Highly Enhanced Performance of Lithium-Oxygen Batteries

Catégorie : défense de thèse
Date : 29/11/2023 14:00 - 29/11/2023 17:00
Lieu : CH21
Orateur(s) : Xing Pengcheng
Organisateur(s) : Bao-Lian Su


  • Dr Luca FUSARO ((Département de Chimie, UNamur), président
  • Prof. Bao-Lian SU (Département de Chimie, UNamur), promoteur et secrétaire
  • Prof. Yu LI (Wuhan University of Technology)
  • Prof. Vincent LIEGEOIS (Département de Chimie, UNamur)
  • Prof. Alain KRIEF (Département de Chimie, UNamur)
  • Dr Tarek BARAKAT (Stûv)
  • Prof. Alexandru VLAD (Institut de la Matière Condensée et des Nanosciences, UCLouvain)


Currently, the increasing scarcity of fossil fuels and environmental pollution have led to a growing focus on the exploration and development of sustainable clean energy sources. Among various energy storage and conversion systems, rechargeable lithium-oxygen (Li-O2) batteries have attracted significant attention due to their ultra-high theoretical energy density. However, practical applications of Li-O2 batteries are still limited by several factors, such as low practical specific capacity, high overpotential, poor cycling stability, and low energy conversion efficiency. The development of catalytic materials that can effectively promote electrode reactions is one of the important approaches to enhance the electrochemical performance of Li-O2 batteries.

Among numerous catalytic materials suitable for Li-O2 batteries, transition metal oxides have been regarded as one of the most promising catalysts due to their excellent catalytic activity in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), as well as their good conductivity, thermal stability, chemical stability, and tunability.In this thesis, we first provide an introduction to the development history of Li-O2 batteries, followed by a detailed explanation of the reaction mechanism and the challenges faced by Li-O2 batteries, along with strategies to address these issues. Our work primarily focuses on the rational design of transition metal oxides as positive electrodes for Li-O2 batteries to improve various aspects of battery performance. The study consists of three main parts:

(1) We investigate the performance of fifth-period transition metal oxides (MOx = Y2O3, ZrO2, NbO2, Nb2O5, MoO3, RuO2, Rh2O3, Ag2O, CdO) as cathodes for Li-O2 batteries, including specific capacity, cycling stability, rate capability, overpotential, and capacity normalized to unit surface area after excluding interference from specific surface area.

(2) Binary transition metal oxides exhibit synergistic enhancement in catalytic activity for ORR and OER. Moreover, the morphology of catalysts significantly affects the electrochemical performance of batteries. Therefore, we select different morphologies of CoMoO4 and study their electrochemical performance as electrodes.

(3) The specific surface area and pore volume of catalysts determine the amount of Li2O2 deposition, thereby influencing the battery performance. Carbon materials derived from renewable biomass sources are considered promising for Li-O2 batteries due to their cost-effectiveness, high specific surface area, and diverse pore structures. Furthermore, we improve the electrochemical performance of Li-O2 batteries by utilizing a composite of Co3O4 with an increased Co3+/Co2+ ratio as a synergistic strategy to enhance the electrocatalytic activity for OER and ORR.


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