Structure and Catalyst Effects on the Electrochemical Performance of Air Electrodes in Lithium‐Oxygen Batteries

Abstract

The lack of systematic understanding of the effects of architecture and catalysts on the electrochemical performance of lithium‐oxygen (Li−O2) batteries hinders the rational design of air electrodes. In this work, we design and synthesize two honeycomb‐like carbon‐based architectures (HCC‐100 and HCC‐500) using a hard template method. With the same amount of Mo2C catalyst loading, the electrochemical performance is compared. At a current density of 100 uA m−2, the discharge capacity of HCC‐100@Mo2C is approximately four times higher than that of HCC‐500@Mo2C m−2. This is attributed to a higher surface area and wider mesopore distribution. Compared to HCC‐100, the material without catalyst loading, the HCC‐100@Mo2C electrode shows a considerable improvement in terms of discharge capacities, cycling stability and capacity retention. The stability of the electrode is tested with IR and SEM analysis after cycling. The SEM micrographs show that discharge products of HCC‐100@Mo2C tend to form on the catalytic site, while the discharge products of HCC‐100 tend to form a thicker layer which could lead to the increased impedance. The results of IR indicate less Li2CO3 by‐product formation with HCC‐100@Mo2C.

Enhanced Electrochemical Behavior of Peanut-Shell Activated Carbon/Molybdenum Oxide/Molybdenum Carbide Ternary Composites

“…From both Figure 8 c,d, it is observed that the PAC/MoO 2 /Mo 2 C-1 electrode depicted the highest C s value in both potential windows reflecting longer charge-discharge pattern which is consistent with the highest current response from the CV curve. However, the smallest C s value of PAC/MoO 2 /Mo 2 C-2 in both potential windows can be explained by the fact that further increasing the molybdenum precursor content could lead to the blockage of some pores in the porous carbon matrix as evidenced by a decrease in SSA of 301 m 2 g −1 and thus limit the ion diffusion at the electrode/electrolyte interface [ 77 ].…”

Ultrafine Ru/RuOx Nanoparticles Uniformly Anchored on Carbon Nanotubes as Cathode Electrocatalyst for Lithium‐Oxygen Batteries

“…Recent years, extensive efforts have been made to solve these problems. Especially the rational design and synthesis of bifunctional electrocatalyst with high activity in catalyzing the ORR and OER involving the reversible reaction of the discharge products of Li 2 O 2 have been proven as an effective strategy. Up to now, various catalysts as cathode materials for Li‐O 2 batteries have been developed, including porous carbon materials, noble metals and alloys and transition metal oxides/nitrides/carbides .…”