An efficiently bifunctional Co₃Mo₃N cathode catalyst for Li-CO₂ batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-CO2 batteries offer high energy density and carbon conversion capabilities for carbon neutrality.
• Challenges include lithium carbonate insulation, high over-potential, and poor cycle performance, hindering practical application.
• Efficient positive catalysts are crucial to reduce reaction activation energy and overcome these barriers.

Purpose of the Study:

• To develop an efficient and practical positive catalyst for lithium-CO2 batteries.
• To improve the performance of lithium-CO2 batteries by addressing issues like high over-potential and poor cycle life.
• To understand the reaction mechanisms through first-principles calculations.

Main Methods:

• Preparation of a CoMoN/C@PPy positive catalyst using polypyrrole (PPy) as a nitrogen source.
• Anchoring Co3Mo3N nanoparticles onto a carbon substrate via nitridation and carbonization of transition metal oxides.
• Utilizing first-principles physics calculations to analyze discharge and charge mechanisms.

Main Results:

• The prepared Li-CO2 batteries demonstrated excellent performance with a specific discharge capacity of 16,567.2 mAh g-1 at 100 mA g-1.
• A stable discharge platform of approximately 2.68 V was achieved.
• The battery exhibited stable cycling for 85 cycles (>1600 hours), indicating improved cycle performance.

Conclusions:

• The developed CoMoN/C@PPy catalyst significantly enhances the performance of Li-CO2 batteries.
• First-principles calculations provide insights into the reaction mechanisms, aiding in catalyst design.
• This research offers a sustainable and cost-effective method for fabricating high-performance electrocatalysts for energy storage applications.