Enhanced graphitization of CO2-derived carbon anodes via Joule heating reformation for high-performance lithium-ion batteries

Abstract

Molten salt electrolysis of CO2 represents a promising technology for highly efficient CO2 capture and the production of economically valuable CO2-derived carbon materials. In this study, we established a 100-A-scale molten salt CO2 electrolysis cell to synthesize hundreds of grams of CO2-derived carbon. Subsequent Joule heating at 2800 °C transformed these materials into high-quality graphite. Further composite modification with asphalt and petroleum coke effectively reduced surface area, resulting in high-performance graphite for lithium-ion battery. The CO2-derived graphite anodes demonstrated high reversible capacities ranging from 297.7 to 378.1 mAh g−1, exhibiting outstanding rate capability and stability over 300 charge-discharge cycles at a current density of 1 A g−1. Finally, we assembled a coin full-cell using AG-2/2/6 anode and LFP cathode, which demonstrated good cycling performance. XPS analysis revealed a significant reduction in oxygen content by the post-reformation, facilitating the formation of highly graphitized structures. This study not only pioneers the up-class synthesis of CO2-derived carbon but also underscores its potential for sustainable energy applications, particularly in lithium-ion battery technology.