Strategies toward High‐Performance Cathode Materials for Lithium–Oxygen Batteries

Abstract

Rechargeable aprotic lithium (Li)-O batteries with high theoretical energy densities are regarded as promising next-generation energy storage devices and have attracted considerable interest recently. However, these batteries still suffer from many critical issues, such as low capacity, poor cycle life, and low round-trip efficiency, rendering the practical application of these batteries rather sluggish. Cathode catalysts with high oxygen reduction reaction (ORR) and evolution reaction activities are of particular importance for addressing these issues and consequently promoting the application of Li-O batteries. Thus, the rational design and preparation of the catalysts with high ORR activity, good electronic conductivity, and decent chemical/electrochemical stability are still challenging. In this Review, the strategies are outlined including the rational selection of catalytic species, the introduction of a 3D porous structure, the formation of functional composites, and the heteroatom doping which succeeded in the design of high-performance cathode catalysts for stable Li-O batteries. Perspectives on enhancing the overall electrochemical performance of Li-O batteries based on the optimization of the properties and reliability of each part of the battery are also made. This Review sheds some new light on the design of highly active cathode catalysts and the development of high-performance lithium-O batteries.

Three-dimensional ordered porous electrode materials for electrochemical energy storage

“…Generally, the ordered macroporous channels enable an effective space for O 2 diffusion and O 2 /Li 2 O 2 conversion, while the ordered mesoporous channels in the electrode can effectively facilitate Li ion diffusion and electron transfer. Although 3DOP carbon materials are commonly utilized in Li-O 2 batteries, one disappointing issue is that carbon-based electrocatalysts are prone to decomposition under the attack of oxygen radicals during the charging process, which may promote the degradation of electrolytes and produce the insulator Li 2 CO 3 141 . The excess byproducts would block further access of Li 2 O 2 to the 3DOP carbon cathode, ultimately leading to premature battery death.…”

Porous Titanium Oxide Microspheres as Promising Catalyst for Lithium–Oxygen Batteries

“…Specifically, oxygen is catalytically reduced in the cathode and reacts with Li + to form Li 2 O 2 during discharge [O 2 + 2Li + + 2e − → Li 2 O 2 , oxygen reduction reaction (ORR)], and Li 2 O 2 is decomposed into Li + and O 2 during charging (Li 2 O 2 → O 2 + 2Li + + 2e − , oxygen evolution reaction) . The practical applications of Li–O 2 batteries have been restricted by many problems, including poor cycle stability, high overpotential during charging, and low charge/discharge rate .…”

Recent Progress on Catalysts for the Positive Electrode of Aprotic Lithium-Oxygen Batteries †

“…To achieve this goal, one of the most effective and direct solutions is to develop positive-electrode catalysts with highly catalytic activity toward the decomposition of Li 2 O 2 [16]. The reported positive-electrode catalysts for Li-O 2 batteries can be mainly divided into three categories, carbon materials, noble-metal-based materials, and transition-metal-based materials [17][18][19][20]. In recent years, tremendous efforts have been devoted to the development of positive-electrode catalysts with better performance and remarkable progress being made, not only with respect to the catalytic performance, but also more importantly, on understanding the recondite electrochemical reactions during battery cycling.…”