In Situ‐Grown ZnCo₂O₄ on Single‐Walled Carbon Nanotubes as Air Electrode Materials for Rechargeable Lithium–Oxygen Batteries

Abstract

The development of highly efficient catalysts is critical for the practical application of lithium-oxygen (Li-O2) batteries. Nanosheet-assembled ZnCo2O4 (ZCO) microspheres and thin films grown in situ on single-walled carbon nanotube (ZCO/SWCNT) composites as high-performance air electrode materials for Li-O2 batteries are reported. The in situ grown ZCO/SWCNT electrodes delivered high discharge capacities, decreased the onset of the oxygen evolution reaction by 0.9 V during the charging process, and led to longer cycling stability. These results indicate that in situ grown ZCO/SWCNT composites can be used as highly efficient air electrode materials for oxygen reduction and evolution reactions. The enhanced catalytic activity displayed by the uniformly dispersed ZCO catalyst on nanostructured electrodes is expected to inspire further development of other catalyzed electrodes for Li-O2 batteries and other applications.

Highly Stable Oxygen Electrodes Enabled by Catalyst Redistribution through an In Situ Electrochemical Method

“…Some new understadnings regarding catalyst effects have been disclosed . Up to now, the reported catalysts can be mainly classified into the following categories: 1) oxides (Co 3 O 4 , NiCo 2 O 4 , MnCo 2 O 4 , ZnCo 2 O 4 , RuO 2 , La 0.75 Sr 0.25 MnO 3 ); 2) carbides (TiC, B 4 C); 3) nitrides (TiN, Co 3 Mo 3 N, Co 4 N); 4) functional carbon materials; 5) noble metals (Au, Pt, PtAu, Ir, Pd, Ag); and 6) conductive polymers (polypyrrole (PPy), polyaniline (PANI)). However, the cycle life of Li−O 2 cells based on most of the abovementioned catalysts is still limited to no more than 100 cycles under a limited discharge/charge capacity protocol of 1000 mAh g −1 in the commonly used electrolytes without the help of efficient redox mediators.…”

Air electrode based on poly(3,4-ethylenedioxythiophene) microflower/graphene composite for superior Li–O2batteries with excellent cycle performance

“…The cycle lives of the non-aqueous Li-O 2 cells are associated with several factors such as the accumulation of reaction products on the air electrode (cathode), electrolyte loss by evaporation and unwanted side reactions, and unstable Li anode. 1,8,9,21 The instability of the Li anode and evaporation of the electrolyte cannot be controlled under our experimental conditions. Thus, the cyclic performance of our electrodes is highly dependent on side reactions such as the formation of Li 2 CO 3 at the Li 2 O 2 /carbon interface and decomposition of the electrolyte during cycling.…”

“…[1][2][3][4][5][6][7] Li-O 2 batteries (also called Li-air batteries) based on new battery chemistry, metal-molecule electrochemical redox couples, have received signicant interest owing to their remarkably high energy density. [8][9][10][11][12][13][14][15] However, the practical application of these batteries is limited by their inherent drawbacks such as high overpotential, low energy efficiency, and short cycle life, which are related to the basic reaction between the oxygen and lithium ions. [8][9][10][11][12][13][14][15] A typical non-aqueous Li-O 2 cell consists of an air electrode (cathode), organic electrolyte, and lithium anode.…”

“…[8][9][10][11][12][13][14][15] However, the practical application of these batteries is limited by their inherent drawbacks such as high overpotential, low energy efficiency, and short cycle life, which are related to the basic reaction between the oxygen and lithium ions. [8][9][10][11][12][13][14][15] A typical non-aqueous Li-O 2 cell consists of an air electrode (cathode), organic electrolyte, and lithium anode. Upon discharging, molecular oxygen is reduced to superoxide, which combines with lithium ions at the air electrode, to form insoluble products (ideally Li 2 O 2 ).…”

Recent Progress on Transition Metal Oxides as Bifunctional Catalysts for Lithium‐Air and Zinc‐Air Batteries

“…Metal ions and graphitic carbon materials can also have a strong beneficial coupling effect ,. Hybrids of atomically thin porous Co 3 O 4 nanosheets and N‐doped reduced graphene oxide (N‐rGO) showed enhanced ORR and OER performance compared to pristine Co 3 O 4 nanosheets and N‐rGO, separately (Figure d–e) .…”